lumber one of the world’s oldest construction material
TRANSCRIPT
Lumber one of the World’s oldest construction material
Terminology
Wood has been the main construction material for centuries, terms used:
Lumber - wood that has been sawed and
milled to size Wood - unprocessed fibrous material
of a tree Timber - large size lumber
Wood Classification
Softwood - evergreen, conifer
Hardwood - broadleaf, deciduous
SOFTWOOD HARDWOOD
Softwoods
Cedars Douglas Fir Firs Hemlock Cypress
Larch Pines Redwood Spruce
Hardwood
Birch Beech Cherry Hickory Mahogany
Chestnut Oak Maple Teak Walnut
Lumber Sizes
Nominal size– used for call out– not actual size– example: 2 x 4
Surfaced or Actual size– used for dimensioning in details– actual size– example: 1 1/2” x 3 1/2”
Lumber Sizes (Actual vs Nominal)
Details are always drawn using actual sizes
Dimensional Lumber vs. Veneer
– Dimensional lumber size always nominal callout– Veneers lumber always use actual size on callout
Nominal vs Surfaced Size Lumber
Nominal2x2
2x4
2x6
2x8
2x10
2x12
4x4
4x6
4x8
Surfaced1 1/2 x 1 1/2
1 1/2 x 3 1/2
1 1/2x 5 1/2
1 1/2 x 7 1/4
1 1/2 x 9 1/4
1 1/2 x 11 1/4
3 1/2 x 3 1/2
3 1/2 x 5 1/2
3 1/2 x 7 1/4
Nominal vs. Surfaced Size Lumber
Nominal6x6
6x8
6x10
6x12
6x14
Surfaced5 1/2 x 5 1/2
5 1/2 x 7 1/4
5 1/2 x 9 1/4
5 1/2 x 11 1/4
5 1/2 x 13 1/4
Dressed Abbreviations for Lumber
S1S Surfaced one side
S2S Surfaced two sides
S4S Surfaced four sides
S1S1E Surfaced one side, one edge
S1S2E Surfaced one side, two edges
S1E Surfaced one edge
Species Selection
Species selection determines characteristics of wood– wood color– grain (open and closed)– hardness or durability
Ultimately determines usage Region of growth determines availability
Grade (Set by Am. Lumber Stds) Sets a standard of lumber quality and values between mills Harmonize natural differences Grade Numbers: (best)Select,1,2,3,Utility(worst)
Certification Marks and Examples
Weyerhaeuser Company Timber Structures Simpson Forest Products Western Wood Products Boise Cascade Trus Joist MacMillan
Moisture Content
Moisture grade stamp mark given at the time of surfacing.– S-DRY--moisture content not exceeding
19 percent.– MC 15--moisture content not exceeding
15 percent.– S-GRN--moisture content exceeded
19 percent.
Division of Lumber Grade & Sizes
Board Lumber (up to 1 1/2” Thick)– appearance grade, sheathing, forms, & select
Dimensional Lumber (up to 4 1/2” Thick)– framing, joist, planks
Timbers (5” or thicker)– beams, stringers, post, timbers
Common Defects
Preservative Treatment
Used to improve the durability and longevity of wood
Primary Reasons for treatment– unsafe moisture water content causing decay– prevent insect damage and termite infestation
Preservative Treatment Wood members
which come in contact with concrete, masonry or earth should be of a treated wood
Preservative Treatment Techniques
Wood is treated by impregnating with toxic chemicals at elevated pressures & temperatures– creosote solutions– oil-borne preservatives– water-borne preservatives– water-repellent preservatives
Lamination Structurally glued lumber
– assembly of wood laminations, dimensional lumber
– grain parallel to length– bonded with adhesive– variety of shapes/sizes– callout is actual size– layers commonly 1-2” thick, with
the common being 1 1/2”
Plywood
Thin veneers glued together perpendicular to one another– odd number of veneers - 3,5,7,9– very strong– used for sheathing, flooring– interior or exterior(X) glues– A,B,C,D surface quality– 4’ x 8’ sheets, Thickness 1/16” thru 1 1/4”
Plywood Grading Stamp APA--trademark=American Plywood Association Span Rating--32/16 or 48/24
– 1st # = max spacing for roof structure– 2nd #=max spacing for subfloor structure
Thickness--15/32” Mill number Exposure Rating--(3)
– Exterior– Exposure 1– Exposure 2
Plywood or Box Beam
Lumber and plywood used together Can be nailed or laminated depending on
the design of the engineer
Engineered Lumber Products Comply: both plywood and OSB
– plywood outside & center veneer Laminated Veneer Lumber (LVL):
– MICRO-LAM, GANG-LAM, STRUCLAM Parallel Strand Lumber Wood I-beam: TJI MDF - Medium Density Fiberboard OSB - Oriented Strand Board Particleboard
More Project Information Do not worry about adding your title block
to sheet A-1, A-2, etc. We will be doing that towards the end of the semester. All drawings are to be full scale.
Drawings will be submitted on a ‘B’ size print until the full set is due at the end of the semester at which time a full plotted D-size set will be turned in for a grade.
Assignment:
Sheet A-3 Elevations Develop all four elevations of your hotel Be sure and use proper material symbols
and notes Add necessary dimensions or datum Use your own design – there are no
restrictions on the elevations – have fun (but don’t let the elevations suck-up all your time
A-DWG3--Beam Types (Layout)
BLT-UP
GLU-LAM BOX
SOLID
Required:
1--Dimension/notes for each beam
2--Title each beam specific type as shown
3--Use symbols for materials
4--Use different line thicknesses to show contrast
5--Text Ref: Figure 5.11 Glu-lam, page 94, Figure 5.2 Solid, page 90, 3-2x10s built-up beam , 12” high w/ 2x4s and 3/4” plywood box beam
6--Each detail, Scale 3” = 1’ - 0”