ms 544 part 2 2001 permissible stress design of solid timber

8/10/2019 MS 544 PART 2 2001 Permissible Stress Design of Solid Timber

http://slidepdf.com/reader/full/ms-544-part-2-2001-permissible-stress-design-of-solid-timber 1/67

MS 544 : PART 2 : 2001

CODE OF PRACTICE FOR STRUCTURALUSE OF TIMBER :PART 2 : PERMISSIBLE STRESS DESIGNOF SOLID TIMBER(FIRST REVISION)

ICS : 91.080.20

Descriptors : permissible stress design, solid timber, timber grades, strength group, flexuralmember, compression member, tension member, built-up beam, spaced column

MALAYSIANSTANDARD

© Copyright

DEPARTMENT OF STANDARDS MALAYSIA

L i c e n s e d t o U N

I V E R S I T I M A L A Y S I A P A H A N G /

D o w n l o

a d e d o n : 2 2 - J u l y - 2 0 0 9 / S i n g l e u s e r l i c e n s e o n l y , c o p y i n g a n d n e t w o r k i n g p r o h i b i t e d



DEVELOPMENT OF MALAYSIAN STANDARDS

The Department of Standards Malaysia (DSM) is the national standardisation and

accreditation body.

The main function of the Department is to foster and promote standards, standardisation and

accreditation as a means of advancing the national economy, promoting industrial efficiency

and development, benefiting the health and safety of the public, protecting the consumers,

facilitating domestic and international trade and furthering international cooperation in relation

to standards and standardisation.

Malaysian Standards are developed through consensus by committees which comprise of

balanced representation of producers, users, consumers and others with relevant interests,

as may be appropriate to the subject in hand. These standards where appropriate are

adoption of international standards. Approval of a standard as a Malaysian Standard is

governed by the Standards of Malaysia Act 1996 (Act 549). Malaysian Standards are

reviewed periodically. The use of Malaysian Standards is voluntary except in so far as they

are made mandatory by regulatory authorities by means of regulations, local by-laws or any

other similar ways.

The Department of Standards appoints SIRIM Berhad as the agent to develop Malaysian

Standards. The Department also appoints SIRIM Berhad as the agent for distribution and

sale of Malaysian Standards.

For further information on Malaysian Standards, please contact:

Department o f Standards Malaysia OR SIRIM Berhad

Tingkat 21, Wisma MPSA 1, Persiaran Dato' MenteriPersiaran Perbandaran P.O. Box 7035, Section 240675 Shah Alam 40911 Shah AlamSelangor D.E. Selangor D.E.

Tel: 60 3 5519 8033 Tel: 60 3 5544 6000Fax: 60 3 5519 2497 Fax: 60 3 5510 8095

http://www.dsm.gov.my http://www.sirim.my

Email:[email protected]



D o w n l o


http://www.dsm.gov.my/

http://www.sirim.my/

mailto:[email protected]

mailto:[email protected]

http://www.sirim.my/

http://www.dsm.gov.my/



MS 544 : PART 2 : 2001

i

CONTENTS

Page

Committee representation............................................................................……………… iv

Foreword……...............................................................................................……………… vi

1 Scope……………………………………………………………………………………. 1

2 Referenced documents……………………………………………………………….. 1

3 Timber specification…………………………………………………………………… 2

4 Species…………………………………………………………………………………. 2

5 Dimensions and geometrical properties…………………………………………….. 2

6 Grades………………………………………………………………………………….. 3

7 Grade stresses for individual species and strength group ……………………….. 3

8 Permissible stresses………………………………………………………………….. 19

9 Duration of loading……………………………………………………………………. 19

10 Load-sharing systems………………………………………………………………… 20

11 Flexural members…………………………………………………………………….. 21

12 Compression members………………………………………………………………. 26

13 Tension members…………………………………………………………………….. 34

Tables

1 Wet grade stresses of timber (N/mm2) moisture content > 19 %………………. 5

2 Dry grade stresses of timber (N/mm2) moisture content ≤ 19 %……………….. 11

3 Strength groups of timber…………………………………………………………… 17



D o w n l o




MS 544 : PART 2 : 2001

ii

CONTENTS (continued)

Page

4 Wet and dry grade stresses for various strength groups of timber (stresses and moduli expressed in N/mm

2)………………………………………. 18

5 Modification factor K1 for duration of loading………………………………………. 20

6 Modification factor K3 for bearing stress……………………………………………. 22

7 Maximum depth to breadth ratios (solid and laminated members)……………… 24

8 Modification factor K7 used to modify the minimum modulus of elasticity for trimmer joints and lintels……………………………………………………………… 26

9 Effective length of compression members………………………………………… 27

10 Modification factor K8 for compression members…………………………………. 29

11 Modification factor K9 for the effective length of spaced columns………………. 33

Tables

Al Names, densities and specific gravity of some structural timbers…………….. 35

Bl Common commercial timber sizes………………………………………………….. 41

B2 Permissible deviations on surfaced timber sizes at 19 % moisture content……. 42

B3a Geometrical properties of sawn timber at wet condition…………………………… 43

B3b Geometrical properties of sawn timber at 19 % moisture content………………. 45

B4 Geometrical properties of dressed sawn timber at 19 % moisture content……. 47

C1 Maximum size of shakes and checks……………………………………………….. 50

C2 Maximum slope of grain………………………………………………………………. 50

C3 Maximum amount of wane……………………………………………………………. 51

C4 Maximum amount of pin, shot and borer holes…………………………………….. 52



D o w n l o




MS 544 : PART 2 : 2001

iii

CONTENTS (continued)

Page

C5 Maximum amount of curvature………………………………………………………. 53

C6 Permissible deviations in curvature…………………………………………………. 54

C7 Maximum width of permissible sound knots……………………………………….. 55

C8 Maximum width of permissible unsound knots…………………………….………. 55

Figures

1 Position of end bearing………………………………………………………………. 21

2 Notched beams………………………………………………………………………. 23

3 Axes in spaced columns…………………………………………………………….. 32

Cl Extent of wane……………………………………………………………………….. 51

C2 Extent of sapwood…………………………………………………………………… 53

C3 Swivel-handed scriber for the determination of slope of grain in wood…………. 56

C4 Use of scriber…………………………………………………………………………. 56

C5 Measurement of slope grain………………………………………………………… 57

Appendices

A Grading of Malaysian structural timbers……………………………….…………… 35

B Sizes and geometrical properties of Malaysian structural timbers……………… 41

C Grading of Malaysian structural timbers……………………………………………. 49

D Modification factor for compression members……………………………………. 58

E Bibliography………………………………….……………………………………….. 59



D o w n l o




MS 544 : PART 2 : 2001

iv

Committee representation

The Building and Civil Engineering Industry Standards Committee (ISC D) under whose supervision this MalaysianStandard was developed, comprises representatives from the following Government Ministries, Trade, Commerceand Manufacturing Associations, and Scientific and Professional Bodies:

Association of Consulting Engineers MalaysiaConstruction Industry Development Board MalaysiaDepartment of Standards MalaysiaDepartment of Occupational Safety and HealthJabatan Bomba dan PenyelamatPertubuhan Akitek MalaysiaMaster Builders Association MalaysiaMinistry of Housing and Local Government (Housing Department)Ministry of Works (Public Works Department)The Institution of Engineers, Malaysia

Universiti Teknologi Malaysia

The development of this Malaysian Standard is under the supervision of the following representatives of the CIDBStandard Committee :

Ir. Mohamed bin Mohd Nuruddin General Manager Technology Development DivisionMegat Kamil Azmi bin Megat Rus Kamarani Senior Manager Standard and Quality UnitPuan Zainora bt Zainal Manager Standard and Quality UnitPuan Hanishahani Othman The Secretary of CIDB Standard Committee

The Technical Committee on Structural Use of Timber which developed this Malaysian Standard consists of thefollowing representatives:

Dr. Abdul Rashid bin Hj. Ab. Malik(Chairman) Forest Research Institute Malaysia

Puan Hanishahani Othman (Secretary) Construction Industry Development Board Malaysia

Tuan Hj. Mohd Shukari bin Midon Forest Research Institute Malaysia

Encik Hilmi bin Md. Tahir Jabatan Kerja Raya Malaysia

Encik Chow Wah/Puan Dang Anom Md. Zin Jabatan Perumahan Negara

Prof. Madya Dr. Sabaruddin bin Mohd Universiti Sains Malaysia

Prof. Dr. Zainai bin Mohamed/Prof. Madya Dr. Abd. Latif bin Saleh Universiti Teknologi Malaysia

Prof. Madya Ir. Dr. Mohd Zamin bin Jumaat Universiti Malaya

Dr. Mohd Ariff bin Jamaludin Universiti Putra Malaysia

Encik Nor Zamri bin Mat Amin Malaysian Timber Industry Board

Ir. Yap Chin Tian Timber Trade Federation Malaysia

Tuan Hj. Wahab bin Abdul Razak General Lumber Fabricators and Builders Bhd

Dr. Peter Kho C.Seng Sarawak Timber Association

Encik Lall Singh Gill Malaysian Wood Moulding and Joint Council

Encik Mohamad Omar b Mohamad Khaidzir Forest Research Institute Malaysia



D o w n l o




MS 544 : PART 2 : 2001

v

Committee representation (continued)

The Working Group on Solid Timber which developed this Malaysian Standard consists of the following

representatives:

Tuan Hj. Mohd Shukari bin Midon (Chairman) Forest Research Institute Malaysia

Puan Hanishahani Othman (Secretary) Construction Industry Development Board Malaysia

Encik Hilmi bin Md. Tahir Jabatan Kerja Raya

Dr. Mohd Ariff bin Jamaludin Universiti Putra Malaysia

Prof. Madya Ir. Dr. Mohd Zamin bin Jumaat Universiti Malaya

Encik Mohd Nor Zamri bin Mat Amin Malaysian Timber Industry Board

Dr. Peter Kho C.Seng Sarawak Timber Association

Ir. Yap Chin Tian Timber Trade Federation Malaysia

Encik Nicolas Roulant General Lumber Fabricators and Builders Bhd.



D o w n l o




MS 544 : PART 2 : 2001

vi

FOREWORD

This Malaysian Standard was developed by the Technical Committee on Structural Use of Timber established at the Construction Industry Development Board Malaysia (CIDB) under the authority of the Building and Civil Engineering Industry Standards Committee.

CIDB is the Standards-Writing Organisation (SWO) appointed by SIRIM Berhad to developstandards for the construction industry.

This standard is referred to BS 5268 : Part 2 : 1996, ‘Code of practice for permissible stress

design, materials and workmanship’.

MS 544 consists of the following parts and sections, under the general title, ‘Code of practice

for structural use of timber’ :

Part 1 : General

Part 2 : Permissible stress design of solid timber

Part 3 : Permissible stress design of glued laminated timber

Part 4 : Timber panel products:

Section 1 : Structural plywood

Section 2 : Marine plywood

Section 3 : Cement bonded particleboard

Section 4 : Oriented strand board

Part 5 : Timber joints

Part 6 : Workmanship, inspection and maintenance

Part 7 : Testing

Part 8 : Design, fabrication and installation of prefabricated timber for roof trusses

Part 9 : Fire resistance of timber structures

Section 1 : Method of calculating fire resistance of timber members

Part 10 : Preservative treatment of structural timbers

Part 11 : Recommendation for the calculation basis for span tables

Section 1 : Domestic floor joistsSection 2 : Ceiling joistsSection 3 : Ceiling bindersSection 4 : Domestic rafters

Part 12 : Laminated veneer lumber for structural application.

This Malaysian Standard supersedes MS 544 : 1978, ‘Code of practice for the structural useof timbers’.

Compliance with a Malaysian Standard does not of itself confer immunity from legal

obligations.



D o w n l o




MS 544 : PART 2 : 2001

1

CODE OF PRACTICE FOR STRUCTURAL USE OF TIMBER :PART 2 : PERMISSIBLE STRESS DESIGN OF SOLID TIMBER

(FIRST REVISION)

1. Scope

This Part gives recommendations for the structural use of the Malaysian hardwood and

softwood timber species in load bearing members. It includes recommendations on quality,

grade stresses and modification factors applicable to these timber when used as simple

members, or as parts of built-up components, or as parts of structures incorporating other

materials. It does not, and it is not intended to deal comprehensively with all aspects of timber construction. In particular it does not cover well tried and traditional methods of timber

construction which have been employed successfully over a long period of time.

2. Referenced documents

The following referenced documents contain provision which, through reference in this text,constitute provisions of this Malaysian Standard. For dated references, where they aresubsequent amendments to, or revisions of, any of these publications do not apply. However,parties to agreements based on this Malaysian Standard are encouraged to investigate thepossibility of applying the most recent editions of the referenced documents. For undated

references, the latest edition of the publication referred to apply.

MS 544 : Part 1 Code of practice for structural use of timber : Part 1 : General.

MS 544 : Part 3 Code of practice for structural use of timber : Part 3 : Permissible stress

design of glued laminated timber.

MS 544 : Part 5 Code of practice for structural use of timber: Part 5 : Timber joints.

BS 6399 : Part 1 : 1984 Loading for buildings: Part 1 : Code of practice for dead and

imposed loads.

BS 6399 : Part 2 : 1995 Loading for buildings : Part 2 : Code of practice for wind loads.

BS 6399 : Part 3 : 1988 Loading for buildings : Part 3 : Code of practice for imposed roof

loads.

CP3 : Chapter V : Part 2 : 1972 Wind loads.

MS 837 : 1985 Method for determination of moisture content of timber.

MS 360 : 1991 Specification for treatment of timber with copper/chrome/arsenic

preservative.



D o w n l o




MS 544 : PART 2 : 2001

2

3. Timber specification

Specifiers should consider and, where necessary, specify requirements under each of the

following headings. All relevant standards should be referenced.

a) Strength group, grade and species.

b) Sizes and surface condition.

c) Service class or moisture content.

d) Durability (see MS 837 : 1985).

e) Preservation and preservatives of timber.

f) Special requirements. These may include more restrictive grade, requirements for

distortion, wane and marking and preservation treatment (see Appendix C).

4. Species

Many factors are involved in the choice of species but from the purely structural view, it is the

grade stresses which are of prime importance. These differ for each species and grade. To

provide an alternative method of specification for the designer and specifiers and greater

flexibility of supply, MS 544 : Part 2 gives a series of strength groups which for design use

can be considered as being independent of species. The list of species under each strength

groups is given in Table 3. For some applications it may be necessary to specify particular

species from within a strength group to take into account of particular characteristics, e.g.

natural durability, amenability to preservatives (see MS 360), glues and fasteners.

Stress values for individual species and grades are given in Tables 1 and 2.

5. Dimensions and geometrical properties

It is essential to include the required actual dimensions of members in specifications, designs,

and drawings. The common commercial timber sizes are given in Table B1 and their

geometrical properties given in Tables B3 and B4 of Appendix B.

Specification should also provide limits and permissible deviations for dimensions as given inTable B2 of Appendix B.

For timber specified in accordance with Appendix B, the design should be based on itsminimum size.

No modifications need to be made to the geometrical properties which change size withmoisture content.



D o w n l o




MS 544 : PART 2 : 2001

3

6. Grades

All timbers used for structural work should be stress graded. The stresses given in MS 544 :Part 2 apply only to timber graded in accordance with Appendix C.

It should be noted that Appendix C is prepared based on the grading limit of Part III : SectionJ of the Malaysian Grading Rules for Sawn Hardwood Timber .

7. Grade stresses for individual species and strength group

7.1 General

Grade stresses for wet and dry conditions are given in Tables 1 and 2 for individual hardwoodand softwood species and Table 4 for each strength groups and grades. As it is difficult andexpensive to artificially dry timber more than 75 mm thick, the wet stresses and moduli shouldnormally be used for solid timber members more than 75 mm thick, unless they are speciallydried.

Design may be based either on the grade stresses for the strength group or on those for theindividual species and grades.

7.2 Clear wood st resses in timber

The clear wood stresses applicable to some structural timber are given in Tables 1 and 2.These are governed by the general characteristics of the particular species, free from all

visible defects and are related to the strength of the timber in wet and dry conditionsrespectively.

In the derivation of clear wood stresses, the following factors have been considered:

a) moisture content;

b) variability; and

c) factors of safety (which includes duration of loading, size and shape of member,accidental overloading, errors in design assumptions, etc.)

7.3 Grade s tresses in sawn t imber

Grade stresses are related to clear wood stresses of the individual species (see 7.2) andgoverned by the effect of visible gross features such as knots, sloping grain etc. (see Appendix C).

The reduction in strength due to a defect is expressed in terms of the strength ratio whichmay be defined as the ratio of the strength of a piece of timber with a defect to the strength of the same piece without a defect. Strength ratios used in reducing the clear wood stresses tothe grade stresses are related to the particular grade and are also governed by the defectswhich influence the particular strength property.

It should be noted that the intrinsic material cost rises with the grade, whilst generalavailability is reduced. At the design stage, reference should be made to commercial sources

for information on the availability of particular species, grades quantities and dimensions.



D o w n l o




MS 544 : PART 2 : 2001

4

The stresses of different grades of timber are given in Tables 1 and 2.

7.4 Strength groups of timbers

Timbers having similar strength and stiffness properties have been grouped together for simplicity in design procedure (see Tables 1 and 4).

The groups thus formed are necessarily based on the weakest species in the particular group.To overcome possible shortages of certain timber species in different regions of Malaysia it is recommended that designs be based on strength groups, and that designersspecify structural timber requirements in terms of strength groups. Where designers wish totake full advantage of the strength of particular species, and where commercial supplies areknown to exist, a particular timber species may be specified, and the grade quoted for

individual species may be used.



D o w n l o




5

Table 1. Wet grade stresses of t imber (N/mm2)

moisture content >>>> 19 %

Bendingparallel to grain

Tensionparallel to grain

Compressionparallel to grain

Compression

perpendicular to grain1)

Timber

Sel Std Com2)

Sel Std Com Sel Std Com Basic Sel Std Com

1 Agoho 22.9 18.1 14.3 13.8 10.8 8.6 20.3 16.0 12.7 4.82 4.10 3.86 3.61

2 Alan bunga3)

13.8 10.9 8.6 8.3 6.5 5.2 12.4 9.8 7.7 1.29 1.10 1.03 0.97

3 Ara 6.9 5.4 4.33)

4.1 3.2 2.6 7.7 6.0 4.8 1.03 0.87 0.82 0.77

4 Babai 12.5 9.8 7.83)

7.5 5.9 4.73)

10.7 8.4 6.7 1.86 1.58 1.49 1.40

5 Balau 30.3 23.9 18.9 18.2 14.3 11.3 26.8 21.1 16.8 4.59 3.90 3.67 3.44

6 Balau, red 18.1 14.2 11.3 10.9 8.5 6.8 15.3 12.0 9.5 2.38 2.02 1.90 1.78

7 Balek angin bopeng 10.8 8.5 6.7 6.5 5.1 4.0 14.7 11.6 9.2 2.59 2.20 2.07 1.94

8 Batai 8.7 6.8 5.4 5.2 4.1 3.2 6.1 4.8 3.8 0.62 0.53 0.50 0.46

9 Bayur 12.2 9.6 7.6 7.3 5.8 4.6 8.5 6.7 5.3 1.64 1.39 1.31 1.23

10 Bekak 20.8 16.4 13.0 12.5 9.8 7.8 17.2 13.5 10.7 3.20 2.72 2.56 2.403

11 Belian3)

29.0 22.8 18.1 17.4 13.7 10.9 28.6 22.6 17.9 5.43 4.62 4.34 4.07

12 Berangan 14.3 11.3 8.9 8.5 6.7 5.4 13.8 10.8 8.6 3.03 2.57 2.42 2.27

13 Bintangor 11.7 9.2 7.3 7.0 5.5 4.4 10.6 8.4 6.6 1.52 1.29 1.22 1.14

14 Bitis 30.0 23.6 18.8 18.0 14.2 11.3 32.3 25.5 20.2 5.53 4.70 4.42 4.15

15 Brazil nut 18.1 14.2 11.3 10.8 8.5 6.8 11.7 9.2 7.3 3.01 2.56 2.41 2.26

16 Chengal 31.6 24.9 19.7 19.0 14.9 11.8 30.2 23.8 18.9 5.85 4.97 4.68 4.39

17 Damar Minyak 9.6 7.6 6.0 5.8 4.6 3.6 8.2 6.5 5.2 1.08 0.92 0.86 0.813

5

L i c e n s e d t o U N I V E R S I T I M A L A Y S I A P A H A N G /

D o w n l o a d e d o n : 2 2 - J

u l y - 2 0 0 9 / S i n g l e u s e r l i c e n s e o n l y , c o p y i n

g a n d n e t w o r k i n g p r o h i b i t e d



MS 544 : PART 2 : 2001

6


moisture content >>>> 19 % (continued)




Compressionperpendicular to gra

Timber

Sel Std Com2)

Sel Std Com Sel Std Com Basic Sel Std Co

18 Dedali 14.2 11.2 8.8 8.5 6.7 5.3 12.2 9.6 7.7 2.26 1.92 1.81 1.

19 Dedaru 28.6 22.5 17.9 17.2 13.5 10.7 23.7 18.7 14.9 3.50 2.97 2.80 2.

20 Delek 21.5 16.9 13.4 12.9 10.1 8.0 16.2 12.7 10.1 3.95 3.36 3.16 2.

21 Derum 15.4 12.1 19.6 9.2 7.3 5.8 14.3 11.3 8.9 2.54 2.16 2.03 1.9

22 Durian 13.1 10.3 8.2 7.9 6.2 4.9 11.4 8.9 7.1 1.41 1.20 1.13 1.

23 Geronggang 9.5 7.5 5.9 5.7 4.5 3.5 6.6 5.2 4.1 0.94 0.80 0.75 0.

24 Gerutu 16.3 12.9 10.2 9.8 7.7 6.1 15.6 12.3 9.7 1.69 1.44 1.35 1.

25 Giam 26.0 20.5 16.3 15.6 12.3 9.8 21.9 17.3 13.7 5.33 4.53 4.26 4.

26 Jelutong 9.4 7.4 5.9 5.6 4.4 3.5 8.0 6.3 5.0 1.02 0.87 0.82 0.7

27 Jenitri 10.1 7.9 6.2 6.0 4.7 3.8 7.8 6.2 4.9 1.02 0.87 0.82 0.

28 Jongkong 11.3 8.9 7.0 6.8 5.3 4.2 9.4 7.4 5.9 1.02 0.87 0.82 0.7

29 Kapur 19.2 15.1 12.0 11.5 9.1 7.2 17.2 13.5 10.8 2.70 2.30 2.16 2.

30 Kasah 10.0 7.9 6.2 6.0 4.7 3.7 9.1 7.2 5.7 1.53 1.30 1.22 1.

31 Kasai 14.9 11.7 9.33)

8.9 7.0 5.63)

12.6 9.9 7.8 2.40 2.04 1.92 1.

32 Kayu Kundur 13.9 11.0 8.7 8.4 6.6 5.2 12.3 9.6 7.7 2.37 2.01 1.90 1.

33 Kedondong 13.3 10.5 8.3 8.0 6.3 5.0 11.4 8.9 7.1 1.50 1.28 1.20 1.

34 Kekatong 26.4 20.8 16.5 15.8 12.5 9.9 22.3 17.6 13.9 4.46 3.79 3.57 3.

6


D o w n l o a d e d o n : 2 2 - J





7






Compressionperpendicular to gra

Timber

Sel Std Com2)


35 Kelat 20.1 15.8 12.53)

12.1 9.5 7.53)

19.7 15.5 12.3 2.41 2.05 1.93 1.

36 Keledang 14.4 11.3 9.0 8.6 6.8 5.4 11.4 8.9 7.1 2.00 1.70 1.60 1.5

37 Kembang semangkok 20.9 16.5 13.1 12.5 9.9 7.9 17.8 14.0 11.1 2.38 2.02 1.90 1.7

38 Kempas 20.7 16.3 13.0 12.4 9.8 7.8 22.3 17.6 13.9 3.73 3.17 3.00 2.

39 Keranji 23.5 18.5 14.7 14.1 11.1 8.8 18.6 14.6 11.6 3.60 3.06 2.88 2.7

40 Keruing 12.3 9.7 7.7 7.4 5.8 4.6 10.2 8.0 6.4 1.97 1.67 1.58 1.

41 Keruntum 17.2 13.5 10.7 10.3 8.1 6.4 16.1 12.7 10.0 2.71 2.30 2.17 2.0

42 Ketapang 14.6 11.5 9.1 8.8 6.9 5.5 9.6 7.6 6.0 1.53 1.30 1.22 1.

43 Kulim 20.2 15.9 12.6 12.1 9.5 7.6 19.1 15.0 11.9 2.55 2.17 2.04 1.

44 Kungkur 16.7 13.2 10.5 10.0 7.9 6.3 12.8 10.1 8.0 2.00 1.70 1.60 1.5

45 Laran 8.8 6.9 5.5 5.3 4.1 3.3 7.6 6.0 4.7 0.95 0.81 0.76 0.7

46 Machang 11.0 8.7 6.9 6.6 5.2 4.1 9.3 7.3 5.8 2.24 1.90 1.79 1.

47 Malabera 17.4 13.7 10.8 10.4 8.2 6.5 13.7 10.8 8.5 3.26 2.77 2.61 2.

48 Mata ulat 27.9 22.0 17.4 16.7 13.2 10.4 23.6 18.6 14.8 4.58 3.89 3.66 3.

49 Medang 13.7 10.8 8.6 8.2 6.5 5.2 11.6 9.1 7.2 1.21 1.03 0.97 0.

50 Melantai/Kawang 10.6 8.4 6.6 6.4 5.0 4.0 8.7 6.9 5.4 1.20 1.02 0.96 0.

51 Melunak 12.8 10.1 8.0 7.7 6.1 4.8 13.7 10.8 8.6 1.92 1.63 1.54 1.

7


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

8






Compression


Timber

Sel Std Com2)


52 Mempening 16.5 13.0 10.3 9.9 7.8 6.2 14.2 11.2 8.9 3.39 2.88 2.71 2.5

53 Mempisang 13.0 10.2 8.1 7.8 6.1 4.9 10.2 8.1 6.4 1.25 1.06 1.00 0.

54 Mengkulang 15.5 12.2 9.7 9.3 7.3 5.8 11.3 8.9 7.1 2.03 1.72 1.62 1.

55 Meransi 21.2 16.7 13.2 12.7 10.0 7.9 17.0 13.3 10.6 3.95 3.36 3.16 2.

56 Meranti bakau 16.1 12.7 10.0 9.7 7.6 6.0 12.4 9.8 7.7 1.83 1.55 1.46 1.

57 Meranti, dark red 14.1 11.1 8.8 8.5 6.7 5.3 11.4 9.0 7.1 1.12 0.95 0.90 0.

58 Meranti, light red 10.8 8.5 6.7 6.5 5.1 4.0 9.6 7.6 6.0 1.10 0.93 0.88 0.

59 Meranti, white 14.8 11.7 9.2 8.9 7.0 5.5 13.4 10.6 8.4 1.28 1.09 1.02 0.

60 Meranti, yellow 11.7 9.2 7.3 7.0 5.5 4.4 10.0 7.9 6.2 1.55 1.32 1.24 1.

61 Merawan 22.9 18.0 14.3 13.7 10.8 8.6 20.3 16.0 12.7 2.72 2.31 2.18 2.

62 Merbatu 24.2 19.0 15.1 14.5 11.4 9.1 18.8 14.8 11.7 3.50 2.97 2.80 2.6

63 Merbau 21.1 16.6 13.2 12.7 10.0 7.9 15.7 12.3 9.8 3.23 2.74 2.58 2.

64 Merpauh 15.7 12.4 9.8 9.4 7.4 5.9 14.4 11.3 9.0 2.35 2.00 1.88 1.

65 Mersawa 12.6 10.0 7.9 7.6 6.0 4.7 10.2 8.0 6.4 2.26 1.92 1.81 1.

66 Mertas 24.8 19.5 15.5 14.9 11.7 9.3 20.1 15.9 12.5 3.50 2.97 2.80 2.6

67 Nyalin 18.2 14.4 11.4 10.9 8.6 6.8 15.0 11.8 9.4 3.53 3.00 2.82 2.

68 Nyatoh 13.7 10.8 8.6 8.2 6.5 5.2 11.8 9.3 7.4 1.99 1.69 1.59 1.

8


D o w n l o a d e d o n : 2 2 - J





9






Compression


Timber

Sel Std Com2)

Sel Std Com Sel Std Com Basic Sel Std C

69 Pauh Kijang 22.2 17.5 13.93)

13.3 10.5 8.33)

25.1 19.8 15.7 2.60 2.21 2.08 1

70 Pelajau 8.2 6.5 5.1 4.9 3.9 3.1 9.3 7.3 5.8 0.68 0.58 0.54 0

71 Penaga 29.2 23.0 18.2 17.5 13.8 10.9 28.9 22.8 18.1 6.68 5.68 5.34 5

72 Penarahan 12.6 9.9 7.9 7.6 5.9 4.7 11.2 8.8 7.0 2.84 2.41 2.27 1

73 Penyau3)

23.4 18.4 14.6 14.0 11.0 8.8 25.2 19.8 15.7 6.05 5.14 4.84 4

74 Perah 19.7 15.5 12.33)

11.8 9.3 7.4 24.8 19.5 15.7 2.73 2.32 2.18 2

75 Perupok 17.5 13.8 10.9 10.5 8.3 6.5 13.8 10.8 8.6 2.00 1.70 1.60 1

76 Petai 11.0 8.7 6.9 6.6 5.2 4.1 9.1 7.2 5.7 1.35 1.15 1.08 1

77 Petaling 19.0 15.0 11.93)

11.4 9.0 7.13)

19.3 15.2 12.0 2.59 2.20 2.07 1

78 Pulai 7.2 5.6 4.5 4.3 3.4 2.7 5.3 4.2 3.3 0.83 0.70 0.66 0

79 Punah 19.3 15.2 12.1 11.6 9.1 7.3 15.0 11.8 9.4 2.64 2.24 2.11 1

80 Ramin 14.2 11.2 8.9 8.5 6.7 5.3 12.4 9.8 7.8 1.87 1.59 1.50 1

81 Ranggu 20.8 16.4 13.0 12.5 9.8 7.8 19.4 15.3 12.1 3.34 2.84 2.67 2

82 Rengas 18.8 14.8 11.8 11.3 8.9 7.1 12.1 9.5 7.6 2.63 2.23 2.10 1

83 Resak 21.1 16.6 13.2 12.7 10.0 7.9 15.0 11.8 9.3 2.92 2.48 2.34 2

84 Rubberwood 12.6 9.9 7.9 7.6 5.9 4.7 9.1 7.2 5.7 2.21 1.88 1.77 1

85 Sengkuang3)

17.0 13.4 10.6 10.2 8.0 6.4 15.2 12.0 9.5 2.26 1.92 1.81 1

9


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

10


moisture content >>>> 19 % (concluded)




Compressionperpendicular to grain

1)Timber

Sel Std Com2)


86 Sepetir 11.0 8.6 6.8 6.6 5.2 4.1 9.4 7.4 5.9 1.92 1.63 1.54 1

87 Sesendok 10.8 8.6 6.8 6.5 5.2 4.1 9.1 7.2 5.7 0.99 0.84 0.79 0

88 Simpoh 16.5 13.0 10.3 9.9 7.8 6.2 18.2 14.3 11.4 2.87 2.44 2.30 2

89 Surian batu 21.0 16.5 13.1 12.6 9.9 7.9 16.7 13.2 10.4 5.06 4.30 4.05 3

90 Teak 16.2 12.8 10.1 9.7 7.7 6.1 12.8 10.1 8.0 2.99 2.54 2.39 2

91 Tembusu 14.2 11.2 8.9 8.5 6.7 5.3 14.8 11.7 9.3 3.20 2.72 2.56 2

92 Terap 10.2 8.1 6.4 6.1 4.9 3.8 7.9 6.2 5.0 1.37 1.16 1.10 1

93 Terentang 6.6 5.2 4.2 4.0 3.1 2.5 5.3 4.2 3.3 0.62 0.53 0.50 0

94 Tualang 22.4 17.6 14.0 13.4 10.6 8.4 18.2 14.3 11.4 3.67 3.12 2.94 2

1) When there is no wane at the bearing area, the basic stress figures may be used for all grades.

2)Sel, Std and Com stand for select structural, standard structural and common building grades respectively as defined in the Malaysian G

3)Figures are estimated due to data not fully available but can be safely used in design.

1 0


D o w n l o a d e d o n : 2 2 - J





11

Table 2. Dry grade stresses of timber (N/mm2)

moisture content ≤≤≤≤ 19 %

Bending

parallel to grain

Tension

parallel to grain

Compression

parallel to grain

Compression


Timber

Sel Std Com2)


1 Agoho 27.1 21.4 17.0 16.3 12.8 10.2 23.3 18.3 14.5 6.00 5.10 4.80 4.

2 Alan bunga3)

15.4 12.2 9.6 9.2 7.3 5.8 14.2 11.2 8.9 1.42 1.21 1.14 1.

3 Ara 8.4 6.6 5.23)

5.0 4.0 3.13)

9.2 7.2 5.7 1.56 1.32 1.25 1.

4 Babai 14.7 11.6 9.2 8.8 7.0 5.5 13.1 10.3 8.2 2.13 1.81 1.70 1.

5 Balau 33.6 26.5 21.0 20.2 15.9 12.6 28.5 22.5 17.8 4.67 3.97 3.74 3.

6 Balau, red 20.2 15.9 12.6 12.1 9.5 7.6 17.8 14.0 11.1 2.82 2.40 2.26 2.

7 Balek angin bopeng 15.8 12.5 9.9 9.5 7.5 5.9 19.1 15.0 11.9 3.82 3.25 3.06 2.

8 Batai 9.7 7.6 6.0 5.8 4.6 3.6 7.0 5.5 4.4 0.77 0.65 0.62 0.

9 Bayur 13.7 10.8 8.6 8.2 6.5 5.2 10.2 8.1 6.4 1.64 1.39 1.31 1.

10 Bekak 26.8 21.1 16.7 16.1 12.7 10.0 22.2 17.5 13.9 3.61 3.07 2.89 2.7

11 Belian3)

31.1 24.5 19.5 18.7 14.7 11.7 30.0 23.6 18.7 5.83 4.96 4.66 4.

12 Berangan 16.8 13.2 10.5 10.1 7.9 6.3 16.8 13.2 10.5 3.34 2.84 2.67 2.

13 Bintangor 15.9 12.5 9.9 9.5 7.5 5.9 14.1 11.2 8.8 1.68 1.43 1.34 1.

14 Bitis 35.9 28.3 22.5 21.5 17.0 13.5 36.0 28.4 22.5 5.60 4.76 4.48 4.

15 Brazil nut 19.0 14.9 11.9 11.4 8.9 7.1 12.8 10.1 8.0 3.40 2.89 2.72 2.

16 Chengal 35.8 28.1 22.3 21.5 16.9 13.4 31.9 25.1 19.9 5.85 4.97 4.68 4.

17 Damar Minyak 13.1 10.3 8.2 7.9 6.2 4.9 11.4 9.0 7.1 1.35 1.15 1.08 1.

1 1


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

12


moisture content ≤≤≤≤ 19 % (continued)





1Timber

Sel Std Com2)


18 Dedali 17.6 13.9 11.0 10.6 8.3 6.6 14.8 11.7 9.3 2.35 2.00 1.88 1

19 Dedaru 32.3 25.5 20.2 19.4 15.3 12.1 26.7 21.0 16.7 3.82 3.25 3.05 2

20 Delek 22.8 17.9 14.2 13.7 10.7 8.5 18.1 14.2 11.3 4.15 3.53 3.32 3

21 Derum 18.2 14.4 11.4 10.9 8.6 6.8 17.7 13.9 11.0 4.37 3.71 3.50 3

22 Durian 15.6 12.3 9.7 9.4 7.4 5.8 13.1 10.3 8.2 1.46 1.24 1.17 1

23 Geronggang 11.0 8.6 6.8 6.6 5.2 4.1 7.8 6.1 4.8 1.13 0.96 0.90 0

24 Gerutu 18.0 14.2 11.2 10.8 8.5 6.7 17.9 14.1 11.2 1.84 1.56 1.47 1

25 Giam 29.7 23.4 18.6 17.8 14.0 11.2 23.3 18.3 14.6 5.89 5.00 4.71 4

26 Jelutong 11.3 8.9 7.1 6.8 5.3 4.3 9.2 7.2 5.8 1.28 1.09 1.02 0

27 Jenitri 12.3 9.7 7.7 7.4 5.8 4.6 10.1 7.9 6.3 1.28 1.09 1.02 0

28 Jongkong 15.0 11.8 9.4 9.0 7.1 5.6 12.3 9.7 7.7 1.36 1.16 1.09 1

29 Kapur 22.0 17.3 13.7 13.2 10.4 8.2 20.4 16.0 12.7 3.00 2.55 2.40 2

30 Kasah 11.3 8.9 7.0 6.8 5.3 4.2 9.6 7.6 6.0 1.68 1.43 1.34 1

31 Kasai 17.2 13.5 10.73)

10.3 8.1 6.43)

15.6 12.3 9.7 2.90 2.46 2.32 2

32 Kayu Kundur 14.6 11.5 9.1 8.8 6.9 5.5 13.5 10.6 8.5 2.68 2.27 2.15 2

33 Kedondong 15.8 12.4 9.8 9.5 7.4 5.9 14.5 11.4 9.1 1.74 1.48 1.39 1

34 Kekatong 33.4 26.3 20.8 20.0 15.8 12.5 26.3 20.7 16.4 4.60 3.91 3.68 3

1 2


D o w n l o a d e d o n : 2 2 - J





13


Moisture content ≤≤≤≤ 19 % (continued)





1Timber

Sel Std Com2)


35 Kelat 23.1 18.2 14.4 13.9 10.9 8.6 24.3 19.2 15.2 2.87 2.44 2.30 2

36 Keledang 15.9 12.5 9.9 9.5 7.5 5.9 12.9 10.1 8.0 2.24 1.90 1.79 1

37 Kembangsemangkok

24.1 19.0 15.0 14.5 11.4 9.0 22.2 17.5 13.9 2.73 2.32 2.18 2

38 Kempas 23.3 18.3 14.6 14.0 11.0 8.8 24.9 19.6 15.6 4.16 3.54 3.33 3

39 Keranji 27.4 21.6 17.2 16.4 13.0 10.3 22.9 18.0 14.3 4.13 3.51 3.30 3

40 Keruing 17.5 13.8 11.0 10.5 8.3 6.6 15.4 12.1 9.6 2.11 1.79 1.67 1

41 Keruntum 20.8 16.4 13.0 12.5 9.8 7.8 19.9 15.7 12.4 3.00 2.55 2.40 2

42 Ketapang 17.8 14.0 11.1 10.7 8.4 6.7 13.6 10.7 8.5 1.91 1.62 1.53 1

43 Kulim 24.7 19.4 15.4 14.8 11.6 9.2 22.5 17.7 14.1 2.77 2.35 2.22 2

44 Kungkur 19.1 15.0 11.9 11.5 9.0 7.1 14.5 11.4 9.0 2.66 2.26 2.13 2

45 Laran 9.9 7.8 6.2 5.9 4.7 3.7 9.6 7.6 6.0 1.30 1.10 1.04 0

46 Machang 13.9 10.9 8.7 8.3 6.5 5.2 11.8 9.3 7.4 2.74 2.33 2.19 2

47 Malabera 20.3 16.0 12.7 12.2 9.6 7.6 16.2 12.7 10.1 3.79 3.22 3.03 2

48 Mata ulat 31.2 24.6 19.5 18.7 14.8 11.7 25.9 20.4 16.2 4.93 4.19 3.94 3

49 Medang 16.0 12.6 10.0 9.6 7.6 6.0 14.4 11.3 9.0 1.44 1.22 1.15 1

50 Melantai/Kawang 11.8 9.3 7.4 7.1 5.6 4.4 10.6 8.3 6.6 1.35 1.15 1.08 1

51 Melunak 14.7 11.6 9.2 8.8 7.0 5.5 15.7 12.3 9.8 2.15 1.83 1.72 1

1 3

L i c e n s e d t o U N I V E R S I T I M A

L A Y S I A P A H A N G /

D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

14






CompressionPerpendicular to grain

1Timber

Sel Std Com2)


52 Mempening 21.9 17.3 13.7 13.1 10.3 8.2 18.6 14.6 11.6 3.68 3.13 2.94 2

53 Mempisang 16.1 12.7 10.1 9.7 7.6 6.1 14.6 11.5 9.1 1.95 1.66 1.56 1

54 Mengkulang 17.8 14.0 11.1 10.7 8.4 6.7 13.4 10.6 8.4 2.47 2.10 1.98 1

55 Meransi 24.2 19.0 15.1 14.5 11.4 9.1 19.5 15.4 12.2 4.68 3.98 3.74 3

56 Meranti bakau 18.2 14.3 11.4 10.9 8.6 6.8 14.1 11.1 8.8 2.06 1.75 1.65 1

57 Meranti, dark red 18.2 14.3 11.4 10.9 8.6 6.8 13.9 11.0 8.7 1.53 1.30 1.22 1

58 Meranti, light red 13.3 10.4 8.3 8.0 6.2 5.0 11.4 8.9 7.1 1.23 1.04 0.98 0

59 Meranti, white 17.1 13.5 10.7 10.3 8.1 6.4 15.7 12.3 9.8 1.62 1.38 1.30 1

60 Meranti, yellow 13.2 10.4 8.2 7.9 6.2 4.9 12.4 9.8 7.7 1.73 1.47 1.38 1

61 Merawan 25.1 19.8 15.7 15.1 11.9 9.4 23.0 18.1 14.4 2.95 2.51 2.36 2

62 Merbatu 29.0 22.8 18.1 17.4 13.7 10.9 23.8 18.8 14.9 4.07 3.46 3.25 3

63 Merbau 24.6 19.4 15.4 14.8 11.6 9.2 17.9 14.1 11.2 4.00 3.40 3.20 3

64 Merpauh 19.2 15.1 12.0 11.5 9.1 7.2 17.4 13.7 10.9 3.22 2.74 2.58 2

65 Mersawa 14.7 11.6 9.2 8.8 7.0 5.5 11.5 9.1 7.2 2.42 2.06 1.94 1

66 Mertas 28.5 22.4 17.8 17.1 13.4 10.7 23.4 18.5 14.7 3.82 3.25 3.05 2

67 Nyalin 22.5 17.7 14.1 13.5 10.6 8.5 19.6 15.5 12.3 4.44 3.77 3.55 3

68 Nyatoh 16.2 12.3 10.1 9.7 7.7 6.1 14.5 11.4 9.0 2.08 1.77 1.66 1

1 4


D o w n l o a d e d o n : 2 2 - J





15







1Timber

Sel Std Com2)


69 Pauh kijang 25.0 19.7 15.603)

15.0 11.8 9.43)

27.7 21.8 17.3 4.80 4.08 3.84 3

70 Pelajau 9.1 7.2 5.7 5.5 4.3 3.4 10.3 8.1 6.4 0.77 0.65 0.62 0

71 Penaga 35.3 27.8 22.1 21.2 16.7 13.3 33.9 26.8 21.2 8.55 7.27 6.84 6

72 Penarahan 14.3 11.3 8.9 8.6 6.8 5.3 13.0 10.2 8.1 4.30 3.65 3.44 3

73 Penyau3)

26.9 21.2 16.8 16.1 12.7 10.1 27.0 21.3 16.9 6.74 5.73 5.39 5

74 Perah 21.8 17.2 13.6 13.1 10.3 8.2 27.0 21.3 16.9 2.99 2.54 2.39 2

75 Perupok 20.6 16.2 12.9 12.4 9.7 7.7 17.9 14.1 11.2 2.80 2.38 2.24 2

76 Petai 12.1 9.5 7.5 7.3 5.7 4.5 11.0 8.6 6.8 1.55 1.32 1.24 1

77 Petaling 21.2 16.6 13.2 12.7 10.0 7.93)

22.4 17.6 14.0 2.61 2.22 2.09 1

78 Pulai 9.0 7.0 5.6 5.4 4.2 3.4 7.7 6.0 4.8 1.02 0.87 0.82 0

79 Punah 25.4 20.0 15.8 15.2 12.0 9.5 21.5 16.9 13.4 3.58 3.04 2.86 2

80 Ramin 19.8 15.5 12.3 11.9 9.3 7.4 17.0 13.4 10.6 2.15 1.83 1.72 1

81 Ranggu 25.2 19.8 15.7 15.1 11.9 9.4 22.9 18.0 14.3 3.65 3.10 2.92 2

82 Rengas 23.1 18.2 14.4 13.9 10.2 8.6 15.2 12.0 9.5 3.32 2.82 2.65 2

83 Resak 23.4 18.4 14.6 14.0 11.0 8.8 17.0 13.4 10.6 3.27 2.78 2.62 284 Rubberwood 13.9 11.0 8.7 8.3 6.6 5.2 10.8 8.5 6.7 2.68 2.28 2.14 2

85 Sengkuang3)

19.8 15.6 12.4 11.9 9.4 7.4 18.3 14.4 11.4 2.59 2.20 2.07 1

1 5


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

16


moisture content ≤≤≤≤ 19 % (concluded)




CompressionPerpendicular to grain

1Timber

Sel Std Com2)


86 Sepetir 13.2 10.3 8.2 7.9 6.2 4.9 11.2 8.8 7.0 2.42 2.06 1.94 1

87 Sesendok 12.2 9.6 7.6 7.3 5.8 4.6 10.9 8.5 6.8 1.11 0.94 0.89 0

88 Simpoh 18.1 14.2 11.3 10.9 8.5 6.8 20.8 16.4 13.0 3.14 2.67 2.51 2

89 Surian batu 23.8 18.7 14.8 14.3 11.2 8.9 21.6 17.0 13.5 6.13 5.20 4.90 4

90 Teak 17.9 14.1 11.2 10.7 8.5 6.7 14.9 11.7 9.3 3.12 2.65 2.50 2

91 Tembusu 17.3 13.6 10.8 10.4 8.2 6.5 16.5 13.0 10.3 3.75 3.19 3.00 2

92 Terap 11.4 8.9 7.1 6.8 5.3 4.3 8.8 6.9 5.5 1.68 1.43 1.34 1

93 Terentang 8.2 6.5 5.1 4.9 3.9 3.1 6.9 5.4 4.3 0.95 0.80 0.76 0

94 Tualang 25.7 20.2 16.1 15.4 12.1 9.7 20.4 16.1 12.8 4.00 3.40 3.20 3

1)When there is no wane at the bearing area, the basic stress figures may be used for all grades.

2)Sel, Std and Com stand for select structural, standard structural and common building grades respectively as defined in the Malaysian G

3)Figures are estimated due to data not fully available but can be safely used in design.

1

6


D o w n l o a d e d o n : 2 2 - J





17

Table 3. Strength groups of timber

S.G. 1 S.G.2 S.G. 3 S.G. 4 S.G. 5 S.G. 6

A) Naturall y Durab le

Balau Belian Bekak Giam TeakBitis Mata ulat Delek Malabera Tembusu

Chengal Kekatong Keranji Merbau

Penaga Resak

B) Requiring Treatment

Dedaru Agoho Berangan Alan bunga Bayur A

Kempas Balau, red Dedali Babai Damar Minyak B

Merbatu Kelat Derum Balek angin bopeng Durian G

Mertas Kembang semangkok Kapur Bintangor Jelutong L

Kulim Kasai Brazil nut Jenitri P

Pauh kijang Keruntum Gerutu Jongkong P

Penyau Mempening Kayu kundur Kasah S

Perah Meransi Kedondong Machang T

Petaling Meranti bakau Keledang MedangRanggu Merawan Keruing Melantai/Kawang

Durian batu Merpauh Ketapang Meranti, light red

Tualang Nyalin Kungkur Meranti, yellow

Perupok Melunak Mersawa

Punah Mempisang Terap

Rengas Mengkulang

Simpoh Meranti, dark red

Meranti, white

Nyatoh

Penarahan

Petai

Ramin

RubberwoodSengkuangSepetir

NOTES:1. For naturally durable timbers, sapwood should be excluded. If sapwood is included, preservative treatment is necessary.(Source: MS360, 192. For timber requiring treatment, they should be amenable to preservative treatment.

1 7


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

18

Table 4. Wet and dry grade stresses for various strength groups of timber

(Stresses and moduli expressed in N/mm2)




Compression


ShStrengthgroups

Condition1)

Sel Std Com3)

Sel Std Com Sel Std Com Basic Sel Std Com Sel

SG 1 Wet 29.2 23.0 18.2 17.5 13.8 10.9 26.8 21.1 16.8 4.59 3.90 3.67 3.44 2.54Dry 33.6 26.5 21.0 20.2 15.9 12.6 28.5 22.5 17.8 4.67 3.97 3.74 3.50 2.94

SG 2 Wet 20.7 16.3 13.0 12.4 9.8 7.8 18.8 14.8 11.7 3.50 2.97 2.80 2.62 2.24Dry 23.3 18.3 14.6 14.0 11.0 8.8 23.4 18.5 14.7 3.82 3.25 3.05 2.86 2.51

SG 3 Wet 18.1 14.2 11.3 10.9 8.5 6.8 15.3 12.0 9.5 2.38 2.02 1.90 1.78 1.84Dry 20.2 15.9 12.6 12.1 9.5 7.6 17.8 14.1 11.1 2.61 2.22 2.09 1.96 2.07

SG 4 Wet 14.2 11.2 8.8 8.5 6.7 5.3 12.1 9.5 7.6 1.83 1.55 1.46 1.37 1.53

Dry 16.8 13.2 10.5 10.1 7.9 6.3 14.1 11.1 8.8 2.06 1.75 1.65 1.54 1.58

SG 5 Wet 11.0 8.6 6.8 6.6 5.2 4.1 9.1 7.2 5.7 1.12 0.95 0.90 0.84 1.21Dry 12.1 9.5 7.5 7.3 5.7 4.5 10.8 8.5 6.7 1.42 1.21 1.14 1.06 1.37

SG 6 Wet 9.4 7.4 5.9 5.6 4.4 3.5 7.9 6.2 5.0 1.02 0.87 0.82 0.76 1.05Dry 11.3 8.9 7.1 6.8 5.3 4.3 8.8 6.9 5.5 1.28 1.09 1.02 0.96 1.11

SG 7 Wet 6.6 5.2 4.2 4.0 3.1 2.5 5.3 4.2 3.3 0.62 0.53 0.50 0.46 0.91Dry 8.2 6.5 5.1 4.9 3.9 3.1 6.9 5.4 4.3 0.77 0.65 0.62 0.58 0.98

1)Moisture content for Wet > 19 %, for dry ≤ 19 %.

2)When there is no wane at the bearing area, the basic stress figures may be used for all grades.

3)Sel, Std and Com stand for select structural, standard structural and common building grades respectively as defined in the Malaysian Gra

1 8


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

19

8. Permissible stresses

8.1 General

Permissible stresses in timber are governed by the particular conditions of service and loading.

8.2 Load inclined to grain

Where the direction of the load is inclined to the grain by an angle α αα α , the permissible compression

stress for the inclined surface is given by the equation:

σσσσc,adm, α = σσσσc,adm,ll − (σσσσc,adm,ll _ σσσσc,adm,⊥)sin α αα α

where σσσσc,adm,ll and σσσσc,adm,⊥ are the grade compression stresses parallel and perpendicular to the grain

respectively, modified as appropriate, for moisture content and / or duration of load (see Clause 9).

8.3 Additional properties

In the absence of specific test data, values which are one-third of those for shear parallel to the grain

(see Tables 1, 2 and 4) should be use for tension perpendicular to the grain, torsional shear and

rolling shear.

For modulus of elasticity perpendicular to grain, a value of one-twentieth (i.e. 0.05) of permissible

modulus of elasticity (see Tables 1, 2 and 4) should be used.

For shear modulus, a value of one-sixteenth (i.e. 0.0625) of permissible modulus of elasticity (see

Tables 1, 2 and 4) should be used.

9. Duration of loading

The stresses given in Tables 1, 2 and 4 apply to long term loading. Table 5 gives the modification

factor K1 by which these should be multiplied for various duration of loading. When advantage is taken

of this clause to use a modification factor K1, greater than unity, the design should be checked to

ensure that the permissible stresses are not exceeded for any other condition of loading that might be

relevant. This modification factor is applicable to all strength properties but is not applicable to moduli

of elasticity or to shear moduli.

For domestic floors, the possible concentrated loading condition given in BS 6399: Part 1 (i.e. 1.4 kN)

may be superimposed on the dead load and both treated as of medium term duration.



D o w n l o




MS 544 : PART 2 : 2001

20

Table 5. Modification factor K1 for duration of loading

Duration of loading Value of K1

Long term (e.g. dead + permanent imposed1))

Medium term (dead + temporary imposed)

Short term (e.g. dead + imposed + wind2))

Very short term (e.g. dead + imposed + wind3)

)

1.00

1.25

1.50

1.75

NOTES:

1)

For uniformly distributed imposed floor loads K1 = 1 except for type 2 and type 3buildings (see Table 5 of BS 6399 : Part 1:1984 (UBBL: 1997) where, for corridors,hallways, landings and stairways only, K1 may be assumed to be 1.5.

2)For wind , short term category applies to class C (15 s gust) as defined in CP3:

Chapter V: Part 2 or, where the largest diagonal dimension of the loaded area a, asdefined in BS 6399: Part 2, exceeds 50 m.

3)For wind, very short term category applies to class A and B ( 3 s or 5 s gust) as

defined in CP3: Chapter V : Part 2 or, where the largest diagonal dimension of the

loaded area a, as defined in BS 6399 : Part 2, does not exceed 50 m.

10. Load-shar ing systems

In a load-sharing system which consists of four or more members such as rafters, joists, trusses or wall studs, spaced a maximum of 610 mm centre to centre, and which has adequate provision for the

lateral distribution of loads by means of purlins, binders, boarding, battens, etc., the following

permissible stresses and moduli of elasticity appropriate to the strength class or species and grade

should apply.

a) The appropriate grade stresses should be multiplied by the load sharing modification factor K2

which has a value of 1.1.

b) The mean modulus of elasticity should be used to calculate deflections and displacements

under both dead and imposed load unless the imposed load is for an area intended for

mechanical plant and equipment, or for storage, or for floors subject to vibrations, e.g.

gymnasia and ballrooms, in which case the minimum modulus of elasticity should be used.

Special provisions for built-up beams, trimmer joists and lintels, and laminated beams, are given in11.10, 11.11 and MS 544 : Part 3 respectively.

The provisions of this clause do not extend to the calculation of modification factor K8 given in Table

10 and Appendix D for load-sharing columns.



D o w n l o




MS 544 : PART 2 : 2001

21

11. Flexural members

11.1 General

Permissible stresses for timber flexural members are governed by the particular conditions of service

and loading as given in Clauses 9 and 10 and by the additional factors given in this clause. They

should be taken as the product of the grade stress given in Clause 7 and the appropriate modification

factors.

11.2 Length and posit ion of bearing

The grade stresses for compression perpendicular to the grain apply to bearings of any length at the

ends of a member, and bearings 150 mm or more in length at any position.

For bearings less than 150 mm long located 75 mm or more from the end of a member, as shown in

Figure 1 the grade stress should be multiplied by the modification factor K3 given in Table 6.

NOTES:

1. At any bearing on the side grain of timber, the permissible stress in compression perpendicular to the grain is dependent onthe length and position of the bearing.

2. No allowance need be made for the difference in intensity of the bearing stress due to rotation of a beam at the supports.

75 mm or Bearing less than

more 150 mm

Figure 1. Position of end bearing



D o w n l o




MS 544 : PART 2 : 2001

22

Table 6. Modification factor K3 for bearing stress

Length of bearing

1)

(mm)

10 15 25 40 50 75 100 150 or

more

Value of K3 1.74 1.67 1.53 1.33 1.20 1.14 1.10 1.00

1)Interpolation is permitted

11.3 Ef fect ive span

The span of flexural members should be taken as the distance between the centres of bearings.

Where members extend over bearings which are longer than is necessary, the spans may be

measured between the centres of bearings of a length which could be adequate according to MS 544

: Part 2. Where advantage is taken of this clause, due attention should be paid to the eccentricity of

the load on the supporting structure.

11.4 Shear at notched ends

Square cornered notches at the ends of a flexural member cause a stress concentration, which

should be allowed for as follows.

The shear strength should be calculated by using the effective depth, he (see Figure 2) and apermissible stress equal to the grade stresses multiplied by the factor K4

where,

a) for a notch on the top edge (see Figure 2(a))

h (he- a) + a h e

K4 = for a ≤ h e

he

2

K4 = 1.0 for a > h e

b) for a notch on the underside (see Figure 2 (b)),

he

K4 =

h

where,

h is the total depth of the beam (mm);

a is as shown in Figure 2 (mm).



D o w n l o




MS 544 : PART 2 : 2001

23

The effective depth, he should be not less than 0.6 h.

a

h

he

a) Beam with notch on the top edge

he

h

b) Beam with notch on the underside.

Figure 2. Notched beams

11.5 Form factor

Grade bending stresses apply to solid timber members of rectangular cross section. For other shapesof cross section, the grade bending stresses should be multiplied by the modification factor K5

where,

K5 = 1.18 for solid circular sections; and

K5 = 1.41 for solid square sections loaded on a diagonal.

11.6 Depth factor

The grade bending stresses given in Tables 1, 2 and 4, apply to material having a depth, h, up to 300

mm.

For depths of beams greater than 300 mm, the grade bending stresses should be multiplied by the

depth modification factor K6 where:

( h2 + 92300)

K6 = 0.81 for solid and glued laminated beams.

(h2

+ 56800)



D o w n l o




MS 544 : PART 2 : 2001

24

11.7 Def lection and st if fness

The dimensions of flexural member should be such as to restrict deflection within limits appropriate to

the type of structure, having regard to the possibility of damage to surfacing materials, ceilings,

partitions and finishing, and to the functional needs as well as aesthetic requirements.

For glued laminated members in addition to the deflection due to bending, the shear deflection may

be significant and should be taken into account.

For most general purposes, this recommendation may be assumed to be satisfied if the deflection of

member when fully loaded does not exceed 0.003 of the span. For domestic floor joists, the deflection

under full load should not exceed 0.003 times the span or 14 mm, whichever is the lesser.

NOTE. 14 mm deflection limitation is to avoid undue vibration under moving or impact loading.

Subject to consideration being given to the effect of excessive deformation, members may be

precambered to account for the deflection under full dead or permanent load, and in this case the

deflection under live or intermittent load should not exceed 0.003 of the span.

The deflection of solid timber members acting alone should be calculated using the minimum modulus

of elasticity for the strength group or species and grade.

The deflections of load-sharing systems, built-up beams, trimmer joists and lintels should be

calculated using the provisions of Clauses 10, 11.10 and 11.11 respectively.

11.8 Lateral support

The depth to breadth ratio of solid and laminated beams of rectangular section should be checked toensure that there is no risk of buckling under design load. Alternatively, the recommendations of Table7 should be followed.

Table 7. Maximum depth to breadth ratios (solid and laminated members)

Degree of lateral support Maximum depth to

breadth ratio

No lateral support 2Ends held in position 3

Ends held in position and member held in line as by purlins or tie rods at centres not more

than 30 times breadth of the member

4

Ends held in position and compression edge held in line, as by direct connection of

sheathing, deck or joists

5

Ends held in position and compression edge held in line, as by direct connection of

sheathing, deck or joists, together with adequate bridging or blocking spaced at intervals

not exceeding 6 times the depth.

6

Ends held in position and both edges held firmly in line 7



D o w n l o




MS 544 : PART 2 : 2001

25

11.9 Notched beams

In calculating the strength of notched or drilled beams, allowance should be made for the notches or

holes, the effective depth being taken as the minimum depth of the net section.

The effect of notches and holes need not be calculated in simply supported floor and roof-joist not

more than 250 mm deep where:

a) notches not exceeding 0.125 of the depth of a joist are located between 0.07 and 0.25 of the

span from the support; and

b) holes drilled at the neutral axis with diameter not exceeding 0.25 of the depth of a joist and

not less than three diameters (centre to centre) apart are located between 0.25 and 0.4 of thespan from the support.

11.10 Bui lt - up beams

Built-up beams should be checked to ensure that there is no risk of buckling under design load.

In built-up members with thin webs, web stiffeners should be provided to ensure the strength and

stability of the member at all points of concentrated load, or elsewhere as may be necessary.

The lateral stability should be determined by calculation, or by consideration of the compression

flange as a column which tends to deflect sideways between points of lateral support, or in

accordance with one of the following:

a) if the ratio of the second moments of area of the cross section about the neutral axis to the

second moment of area about the axis perpendicular to the neutral axis does not exceed 5 to

1, no lateral support is required;

b) if the ratio of the second moments of area is between 5 to 1 and 10 to 1, the ends of the beam

should be held in position at the bottom flange at the supports;

c) if the ratio of the second moments of area is between 10 to 1 and 20 to 1, the beam should be

held in line at the ends;

d) if the ratio of the second moments of area is between 20 to 1 and 30 to 1, one edge should be

held in line;

e) if the ratio of the second moments of area is between 30 to 1 and 40 to 1, the beam should be

restrained by bridging or other bracing at intervals of not more than 2.4 m; and

f) if the ratio of the second moments of area is greater than 40 to 1, the compression flanges

should be fully restrained.

The modification factors K17, K18 and K19 given in Table 7 of MS 544 : Part 3 may be used for the

flanges of glued built-up beams such as box and I-beams. The number of pieces of timber in each

flange should be taken as the number of laminations, irrespective of their orientation, to determine the

value of the stress modification factor K17, K18, and K19 for that flange.



D o w n l o




MS 544 : PART 2 : 2001

26

The total number of pieces of timber in both flanges should be taken as the number of laminations to

determine the value of K18 that is to be applied to the minimum modulus of elasticity for deflection

calculations.

In addition to the deflection of a built-up beam due to bending, the shear deflection may be significant

and should be taken into account.

11.11 Trimmer joists and l intels

For trimmer joists and lintels comprising two or more pieces connected together in parallel and acting

together to support the loads, the grade stresses in bending and shear parallel to the grain, and in

compression perpendicular to the grain should be multiplied by the load-sharing stress modification

factor K2, which has a value of 1.1.

The minimum modulus of elasticity modified by the factor K7 given in Table 8 should be used for the

calculation of deflection.

Table 8. Modification factor K7 used to modify the minimum

modulus of elasticity for trimmer joists and lintels

Number of pieces Values of K7

1 1.00

2 1.06

3 1.08

4 or more 1.10

12. Compression members

12.1 General

The limitations on bow in most stress grading rules are inadequate for the selection of material for

columns. Particular attention should therefore be paid to the straightness of columns, e.g. by limiting

bow to approximately 1/300 of the length.

Permissible stresses for timber members subjected to compression in the direction of the grain aregoverned by the particular conditions of loading given in Clauses 9 and 10 and by the additional

factors given in this clause.

12.2 Size factors

The grade compression stresses given in Tables 2, 3 and 4 apply to all solid timber members graded

in accordance with Section J of the Malaysian Grading Rules.



D o w n l o




MS 544 : PART 2 : 2001

27

12.3 Ef fec tive length

The effective length of a compression member should be derived from either:

a) Table 9 for the particular end conditions; or

b) the deflected form of the compression member as affected by any restraint and/or fixing

moment(s), the effective length being the distance between adjacent points of zero bending

between which the member is in single curvature.

Table 9. Effective length of compression members

End conditionsEffective length

Actual length L

Restrained at both ends in position and in direction 0.7

Restrained at both ends in position and one end in direction 0.85

Restrained at both ends in position but not in direction 1.0

Restrained at one end in position and in direction and at the

other end in direction but not in position

1.5

Restrained at one end in position and in direction and free at

the other end

2.0

12.4 Slenderness rat io

The slenderness ratio of compression members should be calculated as the effective length, Le

divided by the radius of gyration, i.

The slenderness ratio should not exceed 180 for:

a) any compression member carrying dead and imposed loads other than loads resulting from

wind; and

b) any compression member, however loaded, which by its deformation will adversely affect the

stress in another member carrying dead and imposed loads other than wind.

The slenderness ratio should not exceed 250 for:

a) any member normally subject to tension or combined tension and bending arising from dead

and imposed loads, but subject to a reversal of axial stress solely from the effect of wind; and

b) any compression member carrying self weight and wind loads only (e.g. wind bracing).



D o w n l o




MS 544 : PART 2 : 2001

28

12.5 Members subject to axial compression (without bending)

For compression members with slenderness ratios of less than 5, without undue eccentricity of

loading, the permissible stress should be taken as the grade compression parallel to the grain stress

modified as appropriate for duration of load and load sharing (Clauses 9 and 10).

For compression members with slenderness ratios equal to or greater than 5, the permissible stress

should be calculated as the product of the grade compression parallel to the grain stress, modified as

appropriate for size, moisture content, duration of load and load sharing, and the modification factor

K8 given in Table 10 or calculated using the equation in Appendix D.

The value of modulus of elasticity used to enter Table 10 or the equation in Appendix D for bothcompression members acting alone and compression members in load-sharing systems should be

the minimum modulus of elasticity. For members comprising two or more pieces connected together

in parallel and acting together to support the loads, the minimum modulus of elasticity should be

modified by K7 ( see Table 8 ) or K18 (see Table 7 of MS 544: Part 3). For horizontally laminated

members, the modified mean modulus of elasticity should be used (see Clauses 4 and 8 of MS 544 :

Part 3). The compression parallel to the grain stress σ c used to enter Table 10 or the equation in

Appendix D should be the grade stress modified only for duration of loading, and size where

applicable.

When checking that the permissible stresses of a compression member are not exceeded,

consideration should be given to all relevant loading conditions, since in the expression E /σ c,ll , used to

enter Table 10 or the equation in Appendix D, the modulus of elasticity is constant for all load

duration, whereas the compression stress should be modified for duration of loading (Clause 9).



D o w n l o




29

Table 10. Modification factor K8 for compression members

Value of K8

Values of slenderness ratio λ λλ λ (= Le/i )

E/σ σσ σ c,ll < 5 5 10 20 30 40 50 60 70 80 90 100 120 140 160

Equivalent Le/b (for rectangular sections)

< 1.4 1.4 2.9 5.8 8.7 11.6 14.5 17.3 20.2 23.1 26 28.9 34.7 40.5 46.2

400 1.000 0.975 0.951 0.896 0.827 0.735 0.621 0.506 0.408 0.330 0.271 0.225 0.162 0.121 0.094

500 1.000 0.975 0.951 0.899 0.837 0.759 0.664 0.562 0.466 0.385 0.320 0.269 0.195 0.148 0.115

600 1.000 0.975 0.951 0.901 0.843 0.774 0.692 0.601 0.511 0.363 0.363 0.307 0.226 0.172 0.135

700 1.000 0.975 0.951 0.902 0.848 0.784 0.711 0.629 0.545 0.399 0.399 0.341 0.254 0.195 0.154

800 1.000 0.975 0.952 0.903 0.851 0.792 0.724 0.649 0.572 0.430 0.430 0.371 0.280 0.217 0.172

900 1.000 0.976 0.952 0.904 0.853 0.797 0.734 0.665 0.593 0.456 0.456 0.397 0.304 0.237 0.188

1000 1.000 0.976 0.952 0.904 0.855 0.801 0.742 0.677 0.609 0.478 0.478 0.420 0.325 0.255 0.204

1100 1.000 0.976 0.952 0.905 0.856 0.804 0.748 0.687 0.623 0.497 0.497 0.440 0.344 0.272 0.2191200 1.000 0.976 0.952 0.905 0.857 0.807 0.753 0.695 0.634 0.513 0.513 0.457 0.362 0.288 0.233

1300 1.000 0.976 0.952 0.905 0.858 0.809 0.757 0.757 0.643 0.527 0.527 0.472 0.378 0.303 0.247

1400 1.000 0.976 0.952 0.906 0.859 0.811 0.760 0.760 0.651 0.539 0.539 0.486 0.392 0.317 0.259

1500 1.000 0.976 0.952 0.906 0.860 0.813 0.763 0.763 0.658 0.550 0.550 0.498 0.405 0.330 0.271

1600 1.000 0.976 0.952 0.906 0.861 0.814 0.766 0.766 0.664 0.559 0.559 0.508 0.417 0.342 0.282

1700 1.000 0.976 0.952 0.906 0.861 0.815 0.768 0.768 0.669 0.567 0.567 0.518 0.428 0.353 0.292

1800 1.000 0.976 0.952 0.906 0.862 0.816 0.770 0.770 0.673 0.574 0.574 0.526 0.438 0.363 0.302

1900 1.000 0.975 0.952 0.907 0.862 0.817 0.772 0.772 0.677 0.581 0.581 0.534 0.447 0.373 0.312

2000 1.000 0.976 0.952 0.907 0.863 0.818 0.773 0.773 0.681 0.587 0.587 0.541 0.455 0.382 0.320

2 9


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

30

12.6 Members subject to axial compression and bending

A member restrained at both ends, in position but not in direction, and subject to bending and axial

compression should be so proportioned that:

σ m,a,|| σ c,a,||

- + ≤ 1 1.5 σ c,a,|| σ c,adm,||

σ m,adm,|| 1 - x K8

σ e

where,

σ m,a,|| is the applied bending stress;

σ m,adm,|| is the permissible bending stress;

σ c,a,|| is the applied compression stress;

σ c,adm,|| is the permissible compression stress (including K8); and

σ e is the Euler critical stress π2E/(Le / i)2,

where E is the modulus of elasticity given in 12.5.

The effective length of a member subject to axial compression and bending should be that given in12.3.

For members in load-sharing systems (see Clause 10), the permissible bending stress, σm,adm,II, and

the permissible compression stress σc,adm,II, should be multiplied by the load-sharing stressmodification factor K2, which has a value of 1.1, or K17 or K18 ,of MS 544 : Part 3 as applicable.

The dimensions of compression members subject to bending should be such as to restrict deflectionwithin limits appropriate to the type of structure.

12.7 Notch ing and dri ll ing

When it is necessary to notch or drill a compression member, allowance for the notches or holesshould be made in the design.

NOTE. The effect of holes need not be calculated where circular holes with diameters not exceeding 25 % of the width of themember are positioned on the neutral axis at between 25 % and 40 % of the actual length from the end or from a support.

12.8 Spaced columns

A spaced column is composed of two or more equal shafts, spaced apart by end and intermediatepacking blocks, which are glued, bolted, screwed, nailed or connectored in position in accordancewith 12.9 and MS 544 : Part 5.



D o w n l o




MS 544 : PART 2 : 2001

31

The clear space between individual shafts (in which packings are inserted), should not be greater thanthree times the thickness of the shaft, measured in the same plane.

12.9 Packing for spaced columns

12.9.1 End packs

12.9.1.1 Mechanical connections

End packings should be of a length sufficient to accommodate the nails, screws or connectorsrequired to transmit, between the abutting face of the packing and one adjacent shaft, a shear forceequal to:

1.3 Abσ c,a,II

na

where,

A is the total section area of the column;

b is the thickness of the shaft;

σ c,a,II is the applied compression stress;

n is the number of shafts; and

a is the distance between the centres of adjacent shafts.

In addition, the length of the packing measured along the axis of the column should be not less thansix times the thickness of the individual shafts.

12.9.1.2 Glued connections

End packings should be of a length sufficient to provide the glue area required to transmit a shear force between the abutting face of the packing and one adjacent shaft, calculated as given for endpackings mechanically connected. In addition, the length of the packing measured along the axis of the column should be not less than six times the thickness of the individual shaft.

Shop fabrication of spaced columns employing glued packings may be carried out using suitableclamps, or clamping pressure may be obtained by screwing or bolting between column shafts and thepackings. In the latter case, at least four screws or bolts should be provided per packing and theseshould be so spaced as to obtain an even pressure over the area of the packing.



D o w n l o




MS 544 : PART 2 : 2001

32

12.9.2 Intermediate packs

Intermediate packings should be not less than 230 mm long, measured along the axis of column, andshould be designed to transmit, between the abutting face of the packing and one adjacent shaft, ashear force of not less than one half of the corresponding shear force for the end packing (see12.9.1.1).

Where the length of the column does not exceed 30 times the thickness of the shaft, only oneintermediate packing need be provided. In any event, sufficient packings should be provided to ensurethat the greater slenderness ratio ( Le /i ) of the local portion of an individual shaft between packings islimited to either 70, or to 0.7 times the slenderness ratio of the whole column, whichever is the lesser.For the purpose of calculating the slenderness ratio of the local portion of an individual shaft, theeffective length (Le ) should be taken as the length between the centroids of the groups of mechanicalconnectors or glue areas in adjacent packings.

12.10 Permissible stresses for spaced columns

For the purpose of calculating the permissible stress on a spaced column, the radii of gyration shouldbe calculated about the axes X-X and Y-Y as indicated in Figure 3.

The effective length of the column, for buckling about the axes X-X and Y-Y, should be assessed inaccordance with the requirement of Table 11.

a

Y

X X

b b

Y

Figure 3. Axes in spaced columns



D o w n l o




MS 544 : PART 2 : 2001

33

The permissible load should then be taken as the least of the following:

a) that for a solid column (whose area is that of the area of timber) bending about axis X-X;

b) that for a solid column whose area is that of one member of the built-up column, and whoseeffective length is equal to the spacing of the packing pieces, multiplied by the number of shafts; and

c) that for a column bending about the Y-Y axis whose geometrical properties of cross-sectionare those of the built-up column, but whose effective length is multiplied by the modificationfactor K9 given in Table 11 .

Table 11. Modification factor K9 for the effective length of spaced columns

Value of K9

Ratio of space to thickness of the thinner member Method of connection

0 1 2 3Nailed 1.8 2.6 3.1 3.5

Screwed or bolted 1.7 2.4 2.8 3.1

Connectored 1.4 1.8 2.2 2.4

Glued 1.1 1.1 1.3 1.4

12.11 Compression members in triangulated frameworks

Compression members in triangulated frameworks such as trusses and girders (but excluding trussed

rafters designed in accordance with Part 3 of BS 5268) should be designed in accordance with theprevious clauses subject to the following.

a) With continuous compression members, the effective length for the purpose of determiningthe slenderness ratio may be taken as between 0.85 and 1.0 (depending upon the degree of fixity and the distribution of load between node points) times the distance between the nodepoints of the framework for buckling in the plane of the framework and times the actualdistance between effective lateral restraints for buckling perpendicular to the plane of theframework. With roof trusses, purlins or tiling battens may be taken as providing effectivelateral restraints, provided they are adequately fastened to the top chord and are carried backto effective bracing or other support.

With roofs employing rafters adequately fastened to a continuous restraint, e.g. a boarded

covering, it can be taken that effective lateral restraint is provided along the whole length of the rafter.

b) With non-continuous compression members, such as web members in a framework, theeffective length for buckling depends on the type of connection at the ends of the membersand may be calculated using the appropriate end fixity (see Table 9 ).

Where a single bolt or connector at the end of a compression member permits rotation of themember, its effective length should be taken as the actual distance between bolts or connectors.



D o w n l o




MS 544 : PART 2 : 2001

34

Where a web member fastened by glued gusset plates is partially restrained at both ends inposition and direction, the effective lengths for buckling in and out of the plane of the trussshould be taken as 0.9 times the actual distance between the points of intersection of thelines passing through the centroids of the members connected.

c) The recommendations in the first sentences of 12.9.1.1 and 12.9.2 do not apply to spacedcompression members in triangulated frameworks. Intermediate packings should be not lessthan 200 mm long and should be fixed in such a manner as to transmit a tensile force parallelto axis X-X, between the individual members, of not less than 2.5 % of the total axial force inthe spaced compression member.

13. Tension members

13.1 General

Permissible stresses for timber tension members are governed by the particular conditions of loadingas given in Clauses 7, 9 and 10 and by the additional factors given in this clause. They should bedetermined as the product of the grade stress and the appropriate modification factors.

13.2 Members subject to axial tension and bending

Members subject to both bending and axial tension should be so proportioned that :

σ m,a,II σ t,a,II

++++ ≤ 1σ m,adm,II σ t,adm,II

where,

σ m,a,II is the applied bending stress;

σ m,adm,II is the permissible bending stress;

σ t,a,II is the applied tension stress; and

σ t,adm,II is the permissible tension stress.



D o w n l o




35

Appendix AGrading of Malaysian structural timbers

Table A1. Name, densities and specific gravit y of some structural timbers

Class Standard nameor species

combination

Other common name(s) Species yielding the timber Density at 19 %moisturecontent (kg/m

3)

Specificgravity

HeavyHardwoods

Balau Selangan batu (Sab.)Balau, Selangan batu (Sar.)

Shorea spp.; Barbata and Ciliata sub-group of section Eushorea

1000 0.84

Balau red Selangan batu merah (Sab.)Red balau, Red selangan (Sar.)

910 0.65

Belian Eusideroxylon zwageri 1000 0.98

Bitis Nyatoh batu (Sab.)Nyatoh batu (Sar.)

Madhuca utilis, Palaquium ridleyi and P.stellatum

1100 0.98

Chengal Balanocarpus heimii 980 0.82

Giam Selangan (Sab.)Giam (Sar.) A few Hopea spp. producing hard heavytimbers 1000 0.81

Kekatong Katong-katong (Sab.)Katong-katong (Sar.)

Cynometra spp. 1000 0.87

Keranji Keranji (Sab.), Keranji (Sar.) Dialium spp. 1000 0.79

Malangangai Malangangai (Sar.) Eusideroxylon malagangai 750 0.63

Merbau Merbau (Sab.)Merbau (Sar.)

Intsia (Afzelia) palembanica 830 0.69

Penaga Penaga (Sar.) Mesua ferrea 1100 0.97

Penyau Upun (Sab.)Penyau (Sar.)

Upuna borneensis 1000 0.84

Resak Resak (Sab.)Resak (Sar.)

Vatica spp.; Cotylelobium spp. 980 0.82

Tembusu Tamasuk (Sab.)Tembusu (Sar.)

Fagraea spp. 800 0.75

NOTE. Specific gravity (based on oven-dried weight and volume at test).

3 5


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

36

Table A1. Name, densities and specific gravit y of some structural timbers (cont

ClassStandard name

or speciescombination

Other common name (s) Species yielding the timber Density at 19 %

moisturecontent(kg/m

3)

Specificgravity

MediumHardwoods

Alan batu Alan batu, Meraka, Meraka alan, Seringawan(Sar.)

Shorea albida (heavier form) 850 0.71

Bekak Lantupak (Sab.)Jelungan sasak (Sar.)

Amoora spp. 1000 0.76 A

Derum Geronggang, Serungan batu (Sab.)Geronggang, Entemu (Sar.)

Cratoxylum spp. 800 0.69

Entapuloh Buak-buak (Sab.), Entapuluh Teijsmanniodendron spp. 800 0.67

Geriting, Teruntum (Sar.) Lumnitzera spp. 800 0.67

Kandis Bebata (Sab.), Kandis (Sar.) Garcinia spp. 1000 0.84

Kapur Kapur (Sab.)Kapur, Kapur bukit ( Sar.)

Dryobalanops spp. 780 0.69

Kasai Kasai (Sab.), Kasai (Sar.) Pometia spp. 830 0.64

Kayu malam Sabah ebony (Sab.)Kayu malam (Sar.)

Diospyros spp. 830 0.69

Tulang daing Merbau jalat (Sab.), Kedang belum (Sar.) Millettia spp. 830 0.70

Kelat Obah (Sab.)Ubah (Sar.)

Eugenia spp. 830 0.73

Keledang Anjaburi, Buruni (Sab.)Pudau (Sar.)

Most Artocarpus spp. 850 0.51

Kempas Impas (Sab.), Kempas, Menggris (Sar.) Koompassia malaccensis 910 0.74

Keruing Keruing (Sab.), Keruing (Sar.) Dipterocarpus spp. 830 0.64

Keruntum Perepat paya (Sab.)Keruntum (Sar.) Combretocarpus rotundatus 750 0.63Kulim Bawang hutan (Sab.), Bawang hutan(Sar.) Scorodocarpus borneensis 870 0.71

Mata ulat Perupok kuning (Sab.), Bajan (Sar.) Kokoona spp. 950 0.79

Mempening Jabor(Sab.), Empenit (Sar.) Lithocarpus spp. andQuercus spp.

950 0.76

Mengkulang Kembang (Sab.), Mengkulang (Sar.) Heritiera spp. 800 0.55

3 6


D o w n l o a d e d o n : 2 2 - J





37

Table A1. Name, densities and specific gravit y of some structural timbers (cont

ClassStandard nameor Speciescombination

Other common name (s ) Species yi el di ng the timber Density at 19 %moisturecontent(kg/m

3)

Specificgravity

MediumHardwoods(continued)

Meransi Perepat hutan, Meransi (Sab.)Rabong (Sar.)

Carallia spp. 800 0.65 Red-brown w

Merawan, Gagil Gagil, Selangan (Sab.)Giam, Luis, Selangan (Sar.)

Hopea spp. 800 0.67 Yellow when

Merbatu Nyalin, Bangkawang, Merbatu (Sab.)Nyalin, Merbatu (Sar.)

Maranthes corymbosa andParinari spp.

800 0.77 Red-brown w

Merpauh Swintonia spp. 780 Principally Slight-brown t

Mertas Besi (Sab.)Litoh (Sar.)

Ctenolophon parvifolius 900 0.81 Brown to pur

Nyalin Minyak berokNyalin (Sar.)

Xanthophyllum spp. 900 0.76 White to brigstrong orang

Pauh Kijang Tenggilan (Sar.) Irvingia malayana 1100 0.80 Yellow browncore is found

Perah Lampias (Sab.)Perah, Kelampai (Sar.)

Elateriospermum tapos 1100 0.82 Dark-brown wand darker st

Petaling Sentikal (Sar.) Ochanostachys amentacea 1000 0.79 Red-brown to

Punah Tuyot (Sab.)Entuyut (Sar.)

Tetramerista glabra 750 0.67 Straw colour

Ranggu Ranggu (Sab.)Ranggu (Sar.)

Koordersiodendron pinnatum 800 0.67 Pink-brown t

Rengas Rengas (Sab.)Rengas (Sar.)

Gluta spp.; Melanochyla spp. 870 0.65 Bright red witfurniture woopersons.

Semayur Semayur (Sar.) Shorea inaequilateralis 850 0.70 Reddish dark

Senumpul Senumpul (Sar.) Hydnocarpus spp. 850 0.71 Pale yellow t

Simpoh Simpor, Simpoh (Sab.), Simpoh(Sar.)

Dillenia spp. 760 0.63 Red-brown to

Tampoi Belimbing hutan, Kunau-kunau,Limpaung , Rambai hutan (Sab.)Tampoi (Sar.)

Baccaurea spp. 850 0.71 Light yellow-orange-yellow

Tualang Kayu raja, Mengaris (Sab.)Tapang (Sar.)

Koompassia excelsa 850 0.76 Reddish browto a deep cho

3 7


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

40

Table A1. Name, densities and specific gravit y of some structural timbers (conc

ClassStandard name or

speciescombination

Other common name(s ) Spec ies yi el di ng the timber Density at 19 %

moisturecontent

(kg/m3)

Specificgravity

LightHardwoods(continued)

Petai Petai (Sab.)Petai (Sar.)

Parkia spp. 800 0.44

Pulai Pulai (Sab.)Pelai (Sar.)

Alstonia spp. 480 0.35

Ramin, Melawis Ramin, Bidaru (Sab.)Ramin (Sar.)

Gonystylus spp. 650 0.59

Rubberwood Kayu getah, Para rubber (Sab.)Kayu getah, Para rubber (Sar.)

Hevea brasiliensis 600 0.55

Sengkuang Sengkuang (Sab.)Sengkuang (Sar.)

Dracontomelon dao 650 0.54

Sentang Limpaga (Sab.)Ranggu, Sentang (Sar.)

Azadirachta excelsa 750 0.62

Sepetir Sepetir (Sab.)Sepetir, Tampar hantu (Sar.) Sindora spp. 700 0.59

Sesendok Sesendok (Sab.)Terbulan (Sar.)

Endospermum malaccensis 550 0.46

Terap Terap (Sab.)Terap (Sar.)

Artocarpus elasticus, A. scortechniiand Parartocarpus spp.

600 0.42

Terentang Terentang (Sab.)Terentang (Sar.)

Campnosperma spp. 450 0.32

White seraya White seraya (Sab.)Urat mata (Sar.)

Parashorea spp. 600 0.51

Softwoods Damar minyak,Malayan kauri

Mengilan (Sab.)Bindang (Sar.)

Agathis borneensis 480 0.43

Podo Kayu china, Lampias, Rempayan(Sab.)Landin (Sar.)

Podocarpus spp. 700 0.59

Sempilor Sempilor (Sar.) Dacrydium spp. and Phyllocladus

spp.

700 0.58


D o w n l o a d e d o n : 2 2 - J





MS 544 : PART 2 : 2001

41

Appendix B

Sizes and geometrical properties of Malaysian structural timbers

Table B1. Common Commercial Timber Sizes

Minimum timber sizes (mm)Shape Nominal Size (mm x mm)

1

Fullsawn Baresawn Dressed Timber

Square 25 x 25 (1” x 1”)

50 x 50 (2” x 2”)

75 x 75 (3” x 3”)

100 x 100 (4” x 4”)

125 x 125 (5” x 5”)

150 x 150 (6” x 6”)

28 x 28

55 x 56

80 x 81

106 x 106

131 x 131

159 x 159

25 x 25

50 x 50

75 x 75

100 x 100

125 x 125

150 x 150

20 x 20

45 x 45

70 x 70

90 x 90

115 x 115

140 x 140

25 x 50 (1” x 2”)

25 x 75 (1” x 3”)

25 x 100 (1” x 4”)

25 x 125 (1” x 5”)

25 x 150 (1” x 6”)

25 x 175 (1” x 7”)

25 x 200 (1” x 8”)

28 x 56

28 x 81

28 x 106

28 x 131

28 x 159

28 x 184

28 x 212

25 x 50

25 x 75

25 x 100

25 x 125

25 x 150

25 x 175

25 x 200

20 x 45

20 x 70

20 x 90

20 x 115

20 x 140

20 x 165

20 x 190

38 x 50 (1½” x 2”)

38 x 75 (1½” x 3”)

38 x 100 (1½” x 4”)

38 x 125 (1½” x 5”)

38 x 150 (1½” x 6”)

38 x 175 (1½” x 7”)

38 x 200 (1½” x 8”)

41 x 56

41 x 81

41 x 106

41 x 131

41 x 159

41 x 184

41 x 212

38 x 50

38 x 75

38 x 100

38 x 125

38 x 150

38 x 175

38 x 200

33 x 45

33 x 70

33 x 90

33 x 115

33 x 140

33 x 165

33 x 190

50 x 75 (2” x 3”)

50 x 100 (2” x 4”)

50 x 125 (2” x 5”)

50 x 150 (2” x 6”)

50 x 175 (2” x 7”)

50 x 200 (2” x 8”)

55 x 81

55 x 106

55 x 131

55 x 159

55 x 184

55 x 212

50 x 75

50 x 100

50 x 125

50 x 150

50 x 175

50 x 200

45 x 70

45 x 90

45 x 115

45 x 140

45 x 165

45 x 190

63 x 100 (2½” x 4”)

63 x 125 (2½” x 5”)

63 x 150 (2½” x 6”)

63 x 175 (2½” x 7”)

63 x 200 (2½” x 8”)

68 x 106

68 x 131

68 x 159

68 x 184

68 x 212

63 x 100

63 x 125

63 x 163

63 x 175

63 x 200

58 x 90

58 x 115

58 x 140

58 x 165

58 x 190

Rectangle

75 x 100 (3” x 4”)

75 x 125 (3” x 5”)

75 x 150 (3” x 6”)

80 x 106

80 x 131

80 x 159

75 x 100

75 x 125

75 x 175

70 x 90

70 x 115

70 x 140



D o w n l o




MS 544 : PART 2 : 2001

42

Table B2. Permissible deviations on surfaced timber sizes at 19 % moisture content

Permissible deviationNominalDimension , x

(mm)

Maximum reduction by surfacing(mm)

Low (-) High (+)

x ≤100

100 < x < 150

x ≥ 150

3

5

6

0

0

0

0.8

0.8

0.8



D o w n l o




MS 544 : PART 2 : 2001

43

Table B3a. Geometrical properties of sawn timber at wet condit ion

NOMINAL SIZE MINIMUM SIZE AREA SECOND MOMENT OF AREA SECTION MODULUS RADIUS OF GYRATION

X-X Y-Y X-X Y-Y X-X Y-Y

mm x mm mm x mm mm2

mm4

mm4

mm3

mm3

mm mm

25 x 25 22 x 22 625 32552 32552 2604 2604 7.22 7.22

25 x 38 22 x 35 950 114317 49479 3958 6017 10.97 7.22

25 x 50 22 x 47 1250 260417 65104 5208 10417 14.43 7.22

25 x 63 22 x 60 1575 520931 82031 6563 16538 18.19 7.22

25 x 75 22 x 72 1875 878906 97656 7813 23438 21.65 7.22

25 x 100 22 x 95 2500 2083333 130208 10417 41667 28.87 7.22

25 x 125 22 x 120 3125 4069010 162760 13021 65104 36.08 7.22

25 x 150 22 x 145 3750 7031250 195313 15625 93750 43.30 7.22

25 x 175 22 x 169 4375 11165365 227865 18229 127604 50.52 7.22

25 x 200 22 x 194 5000 16666667 260417 20833 166667 57.74 7.22

38 x 38 35 x 35 1444 173761 173761 9145 9145 10.97 10.97

38 x 50 35 x 45 1900 395833 228633 12033 15833 14.43 10.97

38 x 63 35 x 60 2394 791816 288078 15162 25137 18.19 10.97

38 x 75 35 x 72 2850 1335938 342950 18050 35625 21.65 10.97

38 x 100 35 x 95 3800 3166667 457267 24067 63333 28.87 10.97

38 x 125 35 x 120 4750 6184896 571583 30083 98958 36.08 10.97

38 x 150 35 x 145 5700 10687500 685900 36100 142500 43.30 10.97

38 x 175 35 x 169 6650 16971354 800217 42117 193958 50.52 10.97

38 x 200 35 x 194 7600 25333333 914533 48133 253333 57.74 10.97

50 x 50 47 x 47 2500 520833 520833 20833 20833 14.43 14.43

50 x 63 47 x 60 3150 1041863 656250 26250 33075 18.19 14.43

50 x 75 47 x 72 3750 1757813 781250 31250 46875 21.65 14.43

50 x 100 47 x 95 5000 4166667 1041667 41667 83333 28.87 14.43

50 x 125 47 x 120 6250 8138021 1302083 52083 130208 36.08 14.43

50 x 150 47 x 145 7500 14062500 1562500 62500 187500 43.30 14.43

50 x 175 47 x 169 8750 22330729 1822917 72917 255208 50.52 14.43

50 x 200 47 x 194 10000 33333333 2083333 83333 333333 57.74 14.43

63 x 63 60 x 60 3969 1312747 1312747 41675 41675 18.19 18.19

63 x 75 60 x 72 4725 2214844 1562794 49613 59063 21.65 18.19

63 x 100 60 x 95 6300 5250000 2083725 66150 105000 28.87 18.19

63 x 125 60 x 120 7875 10253906 2604656 82688 164063 36.08 18.19

63 x 150 60 x 145 9450 17718750 3125588 99225 236250 43.30 18.19

63 x 175 60 x 169 11025 28136719 3646519 115763 321563 50.52 18.19

63 x 200 60 x 194 12600 42000000 4167450 132300 420000 57.74 18.19

75 x 75 72 x 72 5625 2636719 2636719 70313 70313 21.65 21.65

75 x 100 72 x 95 7500 6250000 3515625 93750 125000 28.87 21.65

75 x 125 72 x 120 9375 12207031 4394531 117188 195313 36.08 21.65

75 x 150 72 x 145 11250 21093750 5273438 140625 281250 43.30 21.65

75 x 175 72 x 169 13125 33496094 6152344 164063 382813 50.52 21.65

75 x 200 72 x 194 15000 50000000 7031250 187500 500000 57.74 21.65



D o w n l o




MS 544 : PART 2 : 2001

44

Table B3a. Geometrical properties of sawn timber at wet condi tion (concluded)



mm x mm mm x mm mm2

mm4

mm4

mm3

mm3

mm mm

100 x 100 95 x 95 10000 8333333 8333333 166667 166667 28.87 28.87

100 x 125 95 x 120 12500 16276042 10416667 208333 260417 36.08 28.87

100 x 150 95 x 145 15000 28125000 12500000 250000 375000 43.30 28.87

100 x 175 95 x 169 17500 44661458 14583333 291667 510417 50.52 28.87

100 x 200 95 x 194 20000 66666667 16666667 333333 666667 57.74 28.87

125 x 125 120 x 120 15625 20345052 20345052 325521 325521 36.08 36.08

125 x 150 120 x 145 18750 35156250 24414063 390625 468750 43.30 36.08

125 x 175 120 x 169 21875 55826823 28483073 455729 638021 50.52 36.08

125 x 200 120 x 194 25000 83333333 32552083 520833 833333 57.74 36.08

150 x 150 145 x 145 22500 42187500 42187500 562500 562500 43.30 43.30

150 x 175 145 x 169 26250 66992188 49218750 656250 765625 50.52 43.30

150 x 200 145 x 194 30000 100000000 56250000 750000 1000000 57.74 43.30

175 x 175 169 x 169 30625 78157552 78157552 893229 893229 50.52 50.52

175 x 200 169 x 194 35000 116666667 89322917 1020833 1166667 57.74 50.52

200 x 200 194 x 194 40000 133333333 133333333 1333333 1333333 57.74 57.74



D o w n l o




MS 544 : PART 2 : 2001

45

Table B3b. Geometrical properties of sawn timber at 19 % moisture content



mm x mm mm x mm mm2

mm4

mm4

mm3

mm3

mm mm

25 x 25 22 x 22 484 19521 19521 1775 1775 6.35 6.35

25 x 38 22 x 35 770 78604 31057 2823 4492 10.10 6.35

25 x 50 22 x 47 1034 190342 41705 3791 8100 13.57 6.35

25 x 63 22 x 60 1320 396000 53240 4840 13200 17.32 6.35

25 x 75 22 x 72 1584 684288 63888 5808 19008 20.78 6.35

25 x 100 22 x 95 2090 1571854 84297 7663 33092 27.42 6.35

25 x 125 22 x 120 2640 3168000 106480 9680 52800 34.64 6.35

25 x 150 22 x 145 3190 5589146 128663 11697 77092 41.86 6.35

25 x 175 22 x 169 3718 8849150 149959 13633 104724 48.79 6.35

25 x 200 22 x 194 4268 13385871 172143 15649 137999 56.00 6.35

38 x 38 35 x 35 1225 125052 125052 7146 7146 10.10 10.10

38 x 50 35 x 45 1645 302817 167927 9596 12886 13.57 10.10

38 x 63 35 x 60 2100 630000 214375 12250 21000 17.32 10.10

38 x 75 35 x 72 2520 1088640 257250 14700 30240 20.78 10.10

38 x 100 35 x 95 3325 2500677 339427 19396 52646 27.42 10.10

38 x 125 35 x 120 4200 5040000 428750 24500 84000 34.64 10.10

38 x 150 35 x 145 5075 8891823 518073 29604 122646 41.86 10.10

38 x 175 35 x 169 5915 14078193 603823 34504 166606 48.79 10.10

38 x 200 35 x 194 6790 21295703 693146 39608 219543 56.00 10.10

50 x 50 47 x 47 2209 406640 406640 17304 17304 13.57 13.57

50 x 63 47 x 60 2820 846000 519115 22090 28200 17.32 13.57

50 x 75 47 x 72 3384 1461888 622938 26508 40608 20.78 13.57

50 x 100 47 x 95 4465 3358052 821932 34976 70696 27.42 13.57

50 x 125 47 x 120 5640 6768000 1038230 44180 112800 34.64 13.57

50 x 150 47 x 145 6815 11940448 1254528 53384 164696 41.86 13.57

50 x 175 47 x 169 7943 18905002 1462174 62220 223728 48.79 13.57

50 x 200 47 x 194 9118 28597087 1678472 71424 294815 56.00 13.57

63 x 63 60 x 60 3600 1080000 1080000 36000 36000 17.32 17.32

63 x 75 60 x 72 4320 1866240 1296000 43200 51840 20.78 17.32

63 x 100 60 x 95 5700 4286875 1710000 57000 90250 27.42 17.32

63 x 125 60 x 120 7200 8640000 2160000 72000 144000 34.64 17.32

63 x 150 60 x 145 8700 15243125 2610000 87000 210250 41.86 17.32

63 x 175 60 x 169 10140 24134045 3042000 101400 285610 48.79 17.32

63 x 200 60 x 194 11640 36506920 3492000 116400 376360 56.00 17.32

75 x 75 72 x 72 5184 2239488 2239488 62208 62208 20.78 20.78

75 x 100 72 x 95 6840 5144250 2954880 82080 108300 27.42 20.78

75 x 125 72 x 120 8640 10368000 3732480 103680 172800 34.64 20.78

75 x 150 72 x 145 10368 17915904 4478976 124416 248832 41.57 20.78

75 x 175 72 x 169 12168 28960854 5256576 146016 342732 48.79 20.78

75 x 200 72 x 194 13968 43808304 6034176 167616 451632 56.00 20.78



D o w n l o




MS 544 : PART 2 : 2001

46

Table B3b. Geometrical properties of sawn timber at 19 % moisture content (concluded)



mm x mm mm x mm mm2

mm4

mm4

mm3

mm3

mm mm

100 x 100 95 x 95 9025 6787552 6787552 142896 142896 27.42 27.42

100 x 125 95 x 120 11400 13680000 8573750 180500 228000 34.64 27.42

100 x 150 95 x 145 13680 23639040 10288500 216600 328320 41.57 27.42

100 x 175 95 x 169 16055 38212238 12074698 254204 452216 48.79 27.42

100 x 200 95 x 194 18430 57802623 13860896 291808 595903 56.00 27.42

125 x 125 120 x 120 14400 17280000 17280000 288000 288000 34.64 34.64

125 x 150 120 x 145 17400 30486250 20880000 348000 420500 41.86 34.64

125 x 175 120 x 169 20280 48268090 24336000 405600 571220 48.79 34.64

125 x 200 120 x 194 23280 73013840 27936000 465600 752720 56.00 34.64

150 x 150 145 x 145 21025 36837552 36837552 508104 508104 41.86 41.86

150 x 175 145 x 169 24505 58323942 42934802 592204 690224 48.79 41.86

150 x 200 145 x 194 28130 88225057 49286104 679808 909537 56.00 41.86

175 x 175 169 x 169 28561 67977560 67977560 804468 804468 48.79 48.79

175 x 200 169 x 194 32786 102827825 78033412 923472 1060081 56.00 48.79

200 x 200 194 x 194 37636 118039041 118039041 1216897 1216897 56.00 56.00



D o w n l o




MS 544 : PART 2 : 2001

47

Table B4. Geometrical properties of dressed sawn timber at 19 % moisture content

NOMINAL SIZE MINIMUM SIZE AREA SECOND MOMENT OF AREA

SECTION MODULUSRADIUS OFGYRATION


mm x mm mm x mm mm2

mm4

mm4

mm3

mm3

mm mm

13 x 100 12 x 90 1080 729000 12960 2160 16200 25.98 3.46

13 x 125 12 x 115 1380 1520875 16560 2760 26450 33.20 3.46

13 x 150 12 x 140 1680 2744000 20160 3360 39200 40.41 3.46

13 x 175 12 x 165 1980 4492125 23760 3960 54450 47.63 3.46

13 x 200 12 x 190 2280 6859000 27360 4560 72200 54.85 3.46

25 x 25 20 x 20 400 13333 13333 13333 13333 5.77 5.77

25 x 38 20 x 33 660 59895 22000 2200 3630 9.53 5.77

25 x 50 20 x 45 900 151875 30000 30000 6750 12.99 5.7725 x 63 20 x 58 1160 325187 38667 3867 11213 16.74 5.77

25 x 75 20 x 70 1400 571667 46667 4667 16333 20.21 5.77

25 x 100 20 x 90 1800 1215000 60000 6000 27000 25.98 5.77

25 x 125 20 x 115 2300 2534792 76667 7667 44083 33.20 5.77

25 x 150 20 x 140 2800 457333 93333 9333 65333 40.41 5.77

25 x 175 20 x 165 3300 7486875 110000 11000 90750 47.63 5.77

25 x 200 20 x 190 3800 11431667 126667 12667 120333 54.85 5.77

38 x 38 33 x 33 1089 98827 98827 5990 5990 9.53 9.53

38 x 50 33 x 45 1485 250594 134764 8168 11138 12.99 9.53

38 x 63 33 x 58 1914 536558 173696 10527 18502 16.74 9.53

38 x 75 33 x 70 2310 943250 209633 12705 26950 20.21 9.53

38 x 100 33 x 90 2970 2004750 209633 16335 44550 25.98 9.53

38 x 125 33 x 115 3795 4182406 269528 20872 72738 33.20 9.53

38 x 150 33 x 140 4620 7546000 344396 25410 107800 40.41 9.53

38 x 175 33 x 165 5445 12353344 419265 29948 149738 47.63 9.53

50 x 50 33 x 190 6270 18862250 494134 34485 198550 54.85 9.53

45 x 45 2025 341719 341719 341719 15188 12.99 12.99

50 x 63 45 x 58 2610 731670 731671 440438 25230 16.74 12.99

50 x 75 45 x 70 3150 1286250 1286250 531563 36750 20.21 12.99

50 x 100 45 x 90 4050 2733750 2733750 683438 60750 25.98 12.99

50 x 125 45 x 115 5175 5703281 5703281 873281 99188 33.20 12.99

50 x 150 45 x 140 6300 10290000 10290000 1063125 147000 40.41 12.99

50 x 175 45 x 165 7425 16845469 16845469 1252969 204187 47.63 12.99

50 x 200 45 x 190 8550 25721250 25721250 1442813 270750 54.85 12.99

63 x 63 58 x 58 3364 943041 943041 32519 32519 16.74 16.7463 x 75 58 x 70 4060 1657833 1138153 39247 47367 20.21 16.74

63 x 100 58 x 90 5220 3523500 1463340 50460 78300 25.98 16.74

63 x 125 58 x 115 6670 7350896 1869823 64477 127842 33.20 16.74

63 x 150 58 x 140 8120 13262667 2276307 78493 189467 40.41 16.74

63 x 175 58 x 165 9570 21711938 2682790 92510 263175 47.63 16.74

63 x 200 58 x 190 11020 33151833 3089273 106527 348967 54.85 16.74

75 x 75 70 x 70 4900 2000833 2000833 57167 57167 20.21 20.21

75 x 100 70 x 90 6300 4252500 2572500 73500 94500 25.98 20.21

75 x 125 70 x 115 8050 8871771 3287083 93917 154292 33.20 20.21

75 x 150 70 x 140 9800 16006667 4001667 114333 228667 40.41 20.21



D o w n l o




MS 544 : PART 2 : 2001

48

Table B4. Geometrical properties of dressed sawn timber at 19 % moisture content(concluded)

NOMINAL SIZE MINIMUM SIZE AREA SECOND MOMENT OF AREA

SECTION MODULUSRADIUS OFGYRATION


mm x mm mm x mm mm2

mm4

mm4

mm3

mm3

mm mm

75 x 175 70 x 165 11550 26204063 4716250 134750 317625 47.63 20.21

75 x 200 70 x 190 13300 40010833 5430833 155167 421167 54.85 20.21

100 x 100 90 x 90 8100 5467500 5467500 121500 121500 25.98 25.98

100 x 125 90 x 115 10350 11406563 6986250 155250 1983375 33.20 25.98100 x 150 90 x 140 12600 20580000 8505000 189000 294000 40.41 25.98

100 x 175 90 x 165 14850 33690938 10023750 222750 408375 47.63 25.98

100 x 200 90 x 190 17100 51442500 11542500 256500 541500 54.85 25.98

125 x 125 115 x 115 13225 14575052 14575052 253479 253479 33.20 33.20

125 x 150 115 x 140 16100 26296667 17743542 308583 375667 40.41 33.20

125 x 175 115 x 165 18975 43049531 20912031 363688 521813 47.63 33.20

125 x 200 115 x 190 21850 65732083 24080521 418792 691917 54.85 33.20

150 x 150 140 x 140 19600 32013333 32013333 457333 457333 40.41 40.41

150 x 175 140 x 165 23100 52408125 37730000 539000 635250 47.63 40.41

150 x 200 140 x 190 26600 80021667 43446667 620667 842333 54.85 40.41

175 x 175 165 x 165 27225 61766719 61766719 748688 748688 47.63 47.63

175 x 200 165 x 190 31350 94311250 71125313 862125 992750 54.85 47.63

200 x 200 190 x 190 36100 108600833 108600833 1143167 1143167 54.85 54.85

NOTE. For more than 200 mm, 6 % reduction on nominal size when calculating the geometrical properties.



D o w n l o




MS 544 : PART 2 : 2001

49

Appendix C

Grading of Malaysian structural timbers

C1. Grade

The timber should be graded, by assessing the characteristics covered by Clauses C1 to C11inclusive on each piece, in the size and condition in which it is to be used, into the followinggrades:

a) select structural;

b) standard structural; and

c) common building.

The grades are multipurpose grades i.e. applicable to all structural timbers whether used asbending members, or in endwise compression. In the case of timber used as beams, therecommended working stresses (as given in Clause 6 Design considerations of MS 544 : Part1) will apply no matter which way up the members intended for resawing to shorter lengths.

The standard structural grade should be specified for normal purposes.

The select structural grade is intended for special purposes, particularly when thestrength/weight ratio of the timber is to be a maximum, for example in towers for transmissionlines and trusses of very long span.

The common building grade is intended for wooden members used in less important parts of building frames, which are not usually designed by means of engineering calculations.

C2. Open shakes, surfaces checks and end checks

C2.1 Measuremen t

The size of an open shake or surface check should be taken as its depth projected into asurface at right angles to the face on which it occurs. The projected depths of all checksoccurring within the middle half of the face should be added together to assess the magnitudeof the total defect.

A feeler gauge of 0.13 mm thickness should be used in measuring the size of an open shake

or surface check.

C2.2 Grad ing limit s

To quality for a particular grade, a member should not have shakes or checks whose size,expressed as a fraction of the width of the face at right angles to the one on which the defectsoccur, exceeds the maximum value given in Table C1.



D o w n l o




MS 544 : PART 2 : 2001

50

Table C1. Maximum size of shakes and checks

Grade Maximum permissible limit

Select

Standard

Common

1/6 thickness

1/3 thickness

½ thickness

C3. Slope of grain

C3.1 Measuremen t

The slope of grain should be measured over a distance sufficiently great to determine thegeneral slope, disregarding slight local deviations (round small knots, etc.). The minimumdistance over which the slope of grain is measured should not ordinarily be less than thedistance over which a deviation of 25 mm is permitted, e.g. a slope of 1 in 15 should bemeasured over distance of not less than 375 mm if possible. A cranked scribe with a freelyswivelling handle should be used. The slope of grain shall be measured on the face or edgewhere it is most severe (see C12).


To quality for a particular grade, a member should not have a slope of grain steeper than the

value given in Table C2.

Table C2. Maximum slope of grain

Grade Maximum slope of grain

Select

Standard

Common

1 in 16

1 in 10.7

1 in 8

C4. Spiral grain

Where spiral grain occurs, the slope of grain should be determined by measuring the worst

slope of grain on the faces and edges and taking the square root of the sum of the square of

the slopes. For example if these slope are 1 in 18 and 1in 12, the combined slope is :

(1/18)

2 + (

1/12)

2 1/2 =

1/10 or a slope of 1 in 10

NOTE. This procedure is intended to apply where it is deemed necessary to measure the slope of grain in mostcases, it will be sufficient for the grader to use his judgement in rejecting timber containing spiral grain to anundesirable extent.



D o w n l o




MS 544 : PART 2 : 2001

52

C6. Borer holes and pin holes

C6.1 Measuremen t

The size of a borer hole shall be taken as the maximum diameter of its visible cross section,no matter where it occurs. Where only a portion of the cross section is visible, the maximumdimension of that portion should be measured.


To qualify for a particular grade, a member shall not have holes that exceed the amount givenin Table C4. However, scattered pinholes and small occasional wormholes are permissible inall grades.

Table C4. Maximum amount of pin, shot and borer holes

Maximum amount of holesGrade

Pin <<<< 1.6 mm φφφφ Shot (1.6 – 3.2 mm φφφφ) Borer (3.2 to 6.4 mm φφφφ)

Select

Standard

Common

16 in 100 cm2

32 in 100 cm2

Unlimited

2 per 900 cm2

4 per 900 cm2

8 per 900 cm2

None

2 per 900 cm2

4 per 900 cm2

C7. Sapwood

Sapwood, though not a structural defect, is liable to attack by fungi and termites if not treated,whether or not the timber is a naturally durable species. Therefore, where durability is themain consideration, the timber with sapwood, even of a naturally durable specifies, should betreated. If not, the sapwood shall be limited so as not to exceed the amount given in TableC3, expressed as a fraction of the width of the surface on which it occurs.



D o w n l o




MS 544 : PART 2 : 2001

53

Figure C2. Extent of sapwood

C8. Stain

Stain, provided the timber is free from decay, is not a structural defect and shall be

acceptable.

C9. Curvature

C9.1 Measuremen t

The extent of curvature is determined by measuring the maximum deviation from a tightly

stretched string or wire, expressed as a ratio of the length of the timber.


To qualify for a particular grade, a member shall not have curvature whose deviation exceedsthe amount given in Table C5.

Table C5. Maximum amount of curvature

Grade Maximum amount of the curvature

Select

Standard

Common

5 mm in 3 m

10 mm in 3 m

15 mm in 3 m

Table C6 shows permissible deviations in curvature for some common lengths.



D o w n l o




MS 544 : PART 2 : 2001

54

Table C6. Permissible deviations in curvature

Permissible deviation (mm)Length of Timber, m

Select grade(5 mm in 3 m)

Standard grade(10 mm in 3 m)

Common grade(15 mm in 3 m)

2 3 7 10

3 5 10 15

4 7 13 20

5 8 17 25

6 10 20 30

7 12 23 35

8 13 27 40

C10. Knots

C10.1 Measurement

The size of a knot shall be taken as the maximum diameter of its visible cross section, nomatter where it occurs. Where the knot can be seen in longitudinal section as well as in crosssection, the longitudinal section should be ignored.

Where two or more knots occur in the same cross section, each knot should be measured as just described and the sum of these measurements taken as a diameter of an equivalentsingle knot.

C10.2 Grading l imits

To qualify for a particular grade, a member shall not have knots whose sizes exceed the

maximum values given in Tables C7 and C8.

C11. Other defects

All pieces showing fungal decay, brittleheart or other abnormal defects affecting strength shallbe excluded from all grades, except in pieces of standard structural and common buildinggrades that have unsound or hollow knots which contain fungal decay. In such cases thepermissible size of unsound knots for the respective grades are as shown in Table C8.



D o w n l o




MS 544 : PART 2 : 2001

55

Table C7. Maximum width of permissible sound knots

Grade Maximum width of knots

Select1/8 dimension of face, to maximum of 38 mm in diameter. 1 per 1 m in length

Standard1/4 dimension of face, to maximum of 75 mm in diameter , 1 per 1 m in length

Common1/3 dimension of face, to maximum of 100 mm in diameter, 1 per 1 m in length

Table C8. Maximum width of permissible unsound knots

Grade Maximum width of knots

Select None

Standard1/6 dimension of face, to maximum of 50 mm diameter, 1 per 2.4 m in length

Common1/4 dimension of face, to maximum of 75 mm diameter, 1 per 2.4 m in length

C12. Guide to the determination of slope of grain

To ascertain the slope of the grain in timber it is necessary to study both the quartered andflat–sawn faces of the member.

If seasoning checks are present, these will indicate the slope of the grain.

Slope of grain can be more accurately determined by means of a scribe, as shown in FigureC3 comprising a cranked rod with a swivel handle and a needle, similar to a gramophoneneedle, at the tip, set to a slight trailing angle. The needle is pressed into the wood and thescribe is drawn along with a steady action in the apparent dissection of the grain, which isindicated more precisely as the needle forms a groove. If the pressure on the needles isinsufficient it may be dragged across the grain: on the other hand, a steady action isimpossible if the pressure is excessive and the needle penetrates too far into the wood.

If the action is correct the needle follows the grain even when the direction of pull of the scribeis slightly out of line. This may be used to check that the scribe does follow the grain byscribing another groove in close proximity on each side of the original one with direction of pull diverging slightly outwards in each case when, if the grooves are following the grain, theywill be parallel to each other.

The inclination of grain on a face is measured as shown in Figures C4 and C5, in which AB isthe line indicating grain direction, AC is a line drawn parallel to the edge of the member, BC isof length one unit (any convenient unit may be used) and is at right angles to AC. Graininclination is expressed as ‘one in x’, where x is the length of AC measured in terms of BC.

The slope of grain should be measured on two adjacent faces, and from the values obtainedthe true inclination of the grain to the longitudinal axis of the member should be determined inaccordance with C4.



D o w n l o




MS 544 : PART 2 : 2001

56

Figure C3. Swivel–handed scriber for the determination of slope of grain in wood

Figure C4. Use of scriber



D o w n l o




MS 544 : PART 2 : 2001

57

Figure C5. Measurement of slope grain



D o w n l o




MS 544 : PART 2 : 2001

58

Appendix D

Modification factor for compression members

The value of the modification factor K8 for compression members with slenderness ratios

equal to or greater than 5 is given by the equation :

1 (1+η)π2E 1 (1+η)π

2E

2π

2E

1/2

K8 = + - + -

2 2Nλ2σ c 2 2Nλ

2σ c Nλ

2σ c

where,

σ c is the compression parallel to the grain stress for the particular conditions of loading

(see 12.5);

E is the appropriate modulus of elasticity for the particular exposure condition (see

12.5);

λ is the slenderness ratio , i.e. the effective column length divided by the radius of gyration (Le/i);

η is the eccentricity factor (taken as 0.005λ in deriving the values given in Table 10);

and

N is the reduction factor used to derive grade compression stresses and moduli of

elasticity and, in this case, has the value 1.5.

For the specific purposes of calculating K8, the minimum value of E (modified if applicable by

K7 or K18 of MS 544 : Part 3, see 8.5) should be used and σc should not include any

allowance, for load sharing.

For compression members acting alone, the permissible stress is :

σc, adm = K8 σc

For compression members in load-sharing systems (see Clause 10), the permissible stress is:

σc, adm = 1.1K8 σc



D o w n l o




MS 544 : PART 2 : 2001

Appendix E

(informative)

Bibliography

E1. AS 1720.1-1998 Timber structures code : Part 1 : Design methods.

E2. AS 1720-1975 Timber engineering code.

E3. BS 6100 : Glossary of building and civil engineering terms.

E4. BS EN 384 : 1995 Structural Timber – Determination of characteristic values of

mechanical properties and density.

E5. Malaysian Grading Rules for Sawn Hardwood Timber 1984 (Ed), MTIB.

E6. Timber Design Handbook. Malayan Forest Records No. 42. 1997, FRIM.

I A P A H A N G /

D o w n l o


ms 544 part 2 2001 permissible stress design of solid timber

Documents