wood basics - lunch & learn
DESCRIPTION
Does specifying wood seem like a foreign language? Then this presentation is for you. You'll receive an overview of wood terminology, applications of wood materials, production of wood, characteristics of wood and relationship with properties, grading, durability, specification and handling as well as an overview of manufactured wood products such as laminated veneer lumber (LVL)TRANSCRIPT
Wood Basics
Terminology, Properties & Specification
Wood Basics © 2011 FWPA
Learn more about wood at UTAS
Centre for Sustainable Architecture with WoodGraduate Certificate in Timber (Processing & Building)• 4 units, part time, onlineAreas covered include:• Wood science• Design for durability and service for life• Timber as a renewable resource• Sustainable design and construction• Engineered wood products• International technologies and developments• Plus, selected topics of individual interestMore information: Associate Professor Greg Nolan (03) 6324 4478 or [email protected]
Wood Basics © 2011 FWPA
Learning Objectives
• Participants completing this activity will be able to:– Describe the essential timber and wood product types– Describe the essential properties of timber and wood
products– Specify timber and wood products
• For architects - AACA Competencies:– Design– Documentation
Wood Basics © 2011 FWPA
This Presentation
• Basics:– Product types– Sizes– Grade & grading
• Structural• Appearance
– Moisture content– Species– Durability and treatment
• Specification
Wood Basics © 2011 FWPA
Timber used in its naturally round shape
Product Types: Round timber
Wood Basics © 2011 FWPA
Timber cut from the log
Product Types: Sawn timber
Wood Basics © 2011 FWPA
Manufactured timber products– Laminated Veneer Lumber (LVL)– Glulam– I-beams
Product Types: Engineered wood products
Wood Basics © 2011 FWPA
Laminated Veneer Lumber (LVL)
Product Types: Engineered wood products
Wood Basics © 2011 FWPA
Glulam
Product Types: Engineered wood products
Wood Basics © 2011 FWPA
I-beams
Product Types: Other wood products
Wood Basics © 2011 FWPA
Product Types: Wood panels
Panel products• Plywood• Hardboard• Particleboard • MDF• Veneer
Wood Basics © 2011 FWPA
Sizing: Terminology
Timber is ordered by actual or nominal dimensions• Nominal dimensions
– approximate size of timber based on its unseasoned condition and rough dimension that it was originally cut to. • e.g. a sleeper of nominal size of 200 x 50 mm will have
actual dimensions less than this. This is to account for shrinkage and any machining that may have occurred
• Actual dimensions– are actual timber size
Wood Basics © 2011 FWPA
Generally;– Seasoned timber - uses actual dimensions – Unseasoned (green) timber– uses nominal
dimensions
Sizing: Terminology
Wood Basics © 2011 FWPA
Timber dimensions – Usually nominate the depth first followed by
breadth– “Depth by breadth”– e.g.
• Studs and joists – 90 x 35 mm• Wall plate and battens – 45 x 70 mm• Joist – 190 x 35 mm
– In North America it’s reversed
Sizing: Terminology
Wood Basics © 2011 FWPA
Availability• Seasoned structural timber usually only available in
35 mm and 45 mm breadth for both hardwood and softwood
• Check with local suppliers before specification, especially outside metro area
Sizing: Availability
Wood Basics © 2011 FWPA
Width (mm)
Thickness (mm)
35 45 70 90
35 - 45 70 90
45 - - 70 90
70 35 45 70 -
90 35 45 70 90
120 35 45 - -
140 35 45 - -
170 35 45 - -
190 35 45 - -
220 35 45 - -
240 35 45 - -
Sizing: Pine Sizes
Wood Basics © 2011 FWPA
Width (mm) Thickness (mm)
35 45
70 35 45
90 35 45
120 35 45
140 35 45
170 35 45
190 35 45
220 35 45
240 35 45
Sizing: Hardwood (seasoned) sizes
Wood Basics © 2011 FWPA
Width (mm)
Thickness (mm)
25 38 50 75 100
50 x x x 75 100
75 x 38 50 75 100
100 x 38 50 75 100
125 x 38 50 75 100
150 x 38 50 75 100
175 25 38 50 75 x
200 x 38 50 75 x
250 25 38 50 x x
Sizing: Hardwood (unseasoned) sizes
Wood Basics © 2011 FWPA
Grade & Grading: Structural
Structural stress grades• F-grades – can be graded visually, mechanically or
proof graded• Applicable to sawn structural timber, round and plywoods
• MGP grades – machine graded, softwoods only• Applicable to sawn structural timber
• GL grades – Glulam grades • LVL and I-beams,
• unique properties to each manufacturer – manufacturers grade
Wood Basics © 2011 FWPA
Grade & Grading
Non-structural grades• Merchant (merch) “grade”• Merch was a structural grade in 60’s / 70’s• No longer recognised as a grade
Wood Basics © 2011 FWPA
Grade & Grading
Structural stress grades• F Grades
• e.g. F5, F7, F8, F17, F27• Visual and/or mechanical testing process• Applies to all softwood, hardwood, plywood
and rounds
• MGP (Machine graded pine) Grades • e.g. MGP 10, MGP 12, MGP 15• Machine tests stiffness of timber• Applies only to radiata, slash, hoop, Caribbean
pine. Some spruce is available
Wood Basics © 2011 FWPA
Grade & Grading
Structural stress grades• Characteristics that affect stress grade:
• Sloping grain• Knots• Fractures
• Some companies also sort on appearance after stress grading (e.g. for pergola framing timbers)
Wood Basics © 2011 FWPA
Grade & Grading
Structural stress gradesMain stress grade limiting characteristics
Dead knotsSlope of grain Live knots
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Grade & Grading
Structural stress gradesLesser stress grade limiting characteristics
Core wood – pith – weaker wood – lower load capacity
Surface checks / fractures – only a problem if they become splits
Wood Basics © 2011 FWPA
Grade & Grading
Structural stress gradesLesser stress grade limiting characteristics
Wane - absence of underbark timberWant – absence of timber other than wane
Bow – curvature along the face Spring – curvature along the edge
Wood Basics © 2011 FWPA
Grade & Grading
Structural stress grades Identification• MGP stress grade is marked with either ink marks,
stamp, end tag or sticker- Ink marks may occur every 1.2 m
• Do not rely on the mill colour marks for grade identification
• Rely on actual grade marking or grade on delivery docket
• If there is more than one grade mark on the timber, ALWAYS go with lowest grade
Wood Basics © 2011 FWPA
Grade & Grading
Structural stress gradesImportantGrading applies at time of grading• So if:
• Forklift splits / tears a chunk out of timber; or• Timber is re-sawn into smaller dimensions
• Member no longer has any stress grade• Timber needs to be regraded or considered as non-
structural
Wood Basics © 2011 FWPA
Grade & Grading: Appearance
Appearance grades products• Flooring and light decking• Lining / panelling• Handrails, balusters, balustrades, stringers, and
treads• Dressed boards, joinery and trim: mouldings,
architraves, skirting boards, shelves, door and window frames
• Cabinets: built in cupboards, benches, furniture• Cladding, fascia
Wood Basics © 2011 FWPA
Grade & Grading: Appearance
Appearance grades• Feature, “colonial” meaningless unless it is
accompanied by a grade description• e.g. in Australian Standard for softwood (AS 4785)
and hardwood have appearance grades• Softwood (AS 4785)
• clear, appearance, select, standard or utility
• Hardwood (AS 2796)• select, medium feature, high feature
Wood Basics © 2011 FWPA
Grade & Grading
Appearance grades productsHardwood appearance grades (AS2796):
• select• medium feature• high feature
Wood Basics © 2011 FWPA
Moisture content
Structural products• Seasoned (S) timber:
• Also called kiln-dried (KD)• Average between 10% and less than or equal to 15%• Minimal additional shrinkage - dimensionally stable• Remain straight - little twisting, cupping or bowing • Well suited for painting
• Unseasoned timber• Also called “green”• >15%
Wood Basics © 2011 FWPA
Moisture content
Appearance productsVaries for each product but generally:
- Interior: not more than 14% and not less than 9%- Exterior: not more than 18% and not less than
10%
Wood Basics © 2011 FWPA
Species
Hardwoods• NSW/Qld – blackbutts, ironbarks, spotted gum,
stringybarks,• Victorian/Tasmanian – Tassie oak, ash species• WA – jarrah, karri• Imported – oak, merbau/kwila, belian
Softwoods• Australia plantation pines – radiata, hoop, slash• Australian native - cypress • Imported – radiata, baltic pine, spruce, Douglas
fir, SPF, western red cedar
Wood Basics © 2011 FWPA
Species
Plantation softwoods• Radiata pine most commonly used plantation grown
softwood timber in Australia• Advantages:
• light-weight• easy to handle and cut• can be finished with a variety of coatings and stains• easily treated to extend durability• high strength to weight ratio • reliable supply and low cost
• Other plantation pines: Slash, Caribbean
Wood Basics © 2011 FWPA
Durability: Basics
Wood Basics © 2011 FWPA
Durability
Natural durability AS 5604 (Relates to heartwood only)
Natural durability class
Probable heartwood life expectancy (years) AS 5604
Inside above ground
(Fully protected from weather and termites)
Outside above ground In-ground contact
Class 1 50+ 40+ 25+Class 2 50+ 15 to 40 15 to 25Class 3 50+ 7 to 15 5 to 15Class 4 50+ 0 to 7 0 to 5
Wood Basics © 2011 FWPA
Durability: Protection from weather
AS 1684: Protected from weather
30 deg
Exposed to weather
Protectedfrom weather
Wood Basics © 2011 FWPA
Durability: In-ground
In-groundNatural durability
classSpecies
Class 1 Ironbarks, tallowwood, turpentine, belian
Class 2Spotted gum, blackbutts, cypress, river red
gum, jarrah
Class 3Brush box, Sydney blue gum, rose/flooded
gum, western red cedar, keruing, messmate, karri, stringybarks,
Class 4
Sapwood of any species, radiata pine, Douglas fir (Oregon), mountain ash /
Tasmanian oak, alpine/Vic ash, meranti, baltic pine, unidentified timbers
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Wood Basics © 2011 FWPA
Durability: Outside above-ground
Outside above-ground
Natural durability class Species
Class 1Ironbarks, tallowwood, turpentine, belian, cypress,
river red gum, spotted gum, blackbutt, kwila (merbau)
Class 2Western red cedar, Jarrah, Sydney blue gum, New
England blackbutt, rose gum
Class 3Brush box, Rose/flooded gum, Keruing, Messmate, Karri, Silver topped stringybark, Kempas, American
white oak
Class 4
Radiata pine, Hoop pine, Slash pineDouglas fir (Oregon), Mountain ash / Tasmanian
oak, Alpine/Vic ash, Meranti, Baltic pine, Unidentified timbers, Sapwood of any species
Above ground durability trials, Beerburrum QLD
Wood Basics © 2011 FWPA
Preservative treatment
Why treat with preservatives?• Extends the life of timbers against borers,
termites and decay• Sapwood has less natural resistance to
insect attack and fungal decay than the heartwood of the same species
• Reliability and proven service life• Lengthen the time that is will sequester
carbon – approx. 50% of the dry weight of wood is carbon - other materials contribute to carbon pollution
Wood Basics © 2011 FWPA
Preservative treatment
• Only sapwood can be effectively treated
• Limit non-treatable timber to 20% cross-section
Bark
Sapwood
Heartwood
Log Sawn Section
Heartwoodcannot be treated thereforedictated by natural durability class
Sapwoodcan betreated toappropriate‘H’ level
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Preservative treatment
Hazard Levels
• Select the level of treatment (H level) required to cope with the environment in which the timber will be used
• H level corresponds to the biological hazard and exposure to the environment
Wood Basics © 2011 FWPA
Preservative treatment
AS 1604 Hazard LevelsHAZARD LEVEL
BIOLOGICALHAZARD
EXPOSURE TYPICAL APPLICATIONS
H1 Borers only Inside, above ground, protected from wetting
Framing, furniture, flooring
H2 Borers and termites Inside, above ground, protected from wetting
Framing, roof trusses, beams, interior battens, flooring
H3 Moderate fungal decay and termites
Outside, above ground, subject to moderate wetting
Weatherboard, fascia, pergolas (above ground), window joinery, decking boards, decking bearers & joists
H4 Severe fungal decay, borers and termites
Outside, in-groundsubject to severe wetting
Fence posts, greenhouses, pergolas (in ground) and landscaping timbers e.g. garden walls, beds and edging
H5 Very severe decay, borers and termites
Outside, in-ground and contact with or in fresh water, subject to extreme wetting
Structural retaining walls, piling, house stumps, building poles
H6 Marine borers and decay
Marine waters, immersed in sea water
Boat hulls, marine piles, jetty cross-bracing, landing steps
OK for use all over Australia
Wood Basics © 2011 FWPA
Preservative treatment
AS 1604 Hazard LevelsHAZARD LEVEL
BIOLOGICALHAZARD
EXPOSURE TYPICAL APPLICATIONS
H2 FH2 S
Borers and termites Inside, above ground, protected from wetting
Framing, roof trusses, beams, interior battens, flooring.
H2 Borers and termites Inside, above ground, protected from wetting
Framing, roof trusses, beams, interior battens, flooring
OK for use South of Tropic of Capricorn only
Wood Basics © 2011 FWPA
Preservative treatment
Envelope treatment
• For hazard levels H1 – H6 preservative must penetrate:
• 100% of the sapwood
• 0 – 20mm of the heartwood
• The exception is for timber framing South of Tropic of Capricorn - Hazard level H2F
Wood Basics © 2011 FWPA
Preservative treatment
Types of preservatives
• Water-borne (CCA, ACQ, copper azole)
• Landscape, fencing, decking, framing, outdoor timber
• In-ground and above ground applications
• LOSP (light organic solvent preservatives)
• Joinery, handrails, H2 framing
• Above ground applications only
• Envelope treatments (blue-pine framing)
• H2F framing south of tropic only
Wood Basics © 2011 FWPA
Preservative treatment
Types of preservatives
• Oil-borne (creosote)
• Power poles, marine, vineyard sticks
• In-ground or in water use
• Supplementary brush/spray/dip (e.g. copper naphthenate)
• Glue-line
• LVL, plywood, particleboard flooring
• Hazard level H2S (south of Tropic of Capricorn only)
Wood Basics © 2011 FWPA
Specification
Depth (mm) x Breath (mm) x Length (mm or m)
In-ground / Above Ground Durability Class 1, 2, 3 or 4
Pine: Clear, Appearance, Utility
F5, F7, F8, F14, F17, F22, F27, F32
Wood Basics © 2011 FWPA
Wood Basics: Specification
Wood Basics © 2011 FWPA
Specification
Specifying wood products
• Application – framing, flooring, pergola, kitchen, fascia, cladding, formwork?
• Performance – appearance, structural performance, service life, cost?
• Environment – inside/outside, exposure to decay and/or termites, exposure to weathering, marine, poolside?
Wood Basics © 2011 FWPA
Future Wood Products
Cross Laminated Timber (CLT)
Architects: Waugh ThistletonProject: Murray Grove, London
Wood Basics © 2011 FWPA
More Information
Wood Basics © 2011 FWPA
Learn more about wood at UTAS
Centre for Sustainable Architecture with WoodGraduate Certificate in Timber (Processing & Building)• 4 units, part time, onlineAreas covered include:• Wood science• Design for durability and service for life• Timber as a renewable resource• Sustainable design and construction• Engineered wood products• International technologies and developments• Plus, selected topics of individual interestMore information: Associate Professor Greg Nolan (03) 6324 4478 or [email protected]