Lecture 10 Lecture 14

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Wood & Lumber Basics
Arch 330
Fall 2008
Look at Master Format2004
Division 06- Wood, Plastics and Composites
Maintenance
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Cleaning, Rehabilitation, Restoration, Preservation
Wood Treatment
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Fire-Retardant Wood Treatment
Preservation Wood Treatment
Eradication of Insects in Wood
Antiseptic Treatment of wood
Shop Applied Wood Coatings
Look at Master Format2004
Division 06- Wood, Plastics and Composites
Rough Carpentry
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Wood Framing
Structural Panels
Heavy Timber
Treated Wood Foundations
Wood Decking
Sheathing
Shop Fabricated Structural Wood (Manufactured Wood
Products)
Glued-Laminated Construction
Look at Master Format2004
Division 06- Wood, Plastics and Composites
Finish Carpentry
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Millwork
Pre-finished Paneling
Architectural Woodwork
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Wood Casework
Wood Paneling
Wood Stairs and Railings
Ornamental Woodwork
Wood Trim
Wood Frames
Structural Plastics and Composites
Wood Treatment
Fire Retardant Treatment
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New Issues
Decay-Insect Resistance
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Pressure treated –preservatives (30)yrs.
Reduces disadvantages does not eliminate them
“The Future”
Renewable Resources
Old Growth Good
Alternate Wood Products
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Our own material lab- patents on several manufactured
products
SIPs-Structural Insulated Panels
Disadvantages of
Wood Construction
Can decay, needs care with use, treating or
coating
Is flammable –needs covering or treating in
many uses especially in Engineered Wood
Products
Quality and availability have decreased
Poor insulation characteristics – need to
coordinate with insulation
Rays
Wood & Lumber Basics
Trees are divided up into two broad
categories:
Hardwoods
 Softwoods
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Please note:
This has nothing to do with the softness or
hardness of the wood.
Balsa Wood is actually classified as a
hardwood!
Wood & Lumber Basics
Better to divide wood into two broad
categories: (I.e. Botany Terms)
- Thus  Hardwoods are Angiosperms (apple)
Seeds on the inside of the fruit and have a flower.
 With few exceptions they loose there leaves
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Softwoods are Gymnosperms (Pinecone)
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Seeds are exposed usually in a cone.
Wood & Lumber Basics
Main Entry: an·gio·sperm
Pronunciation: 'an-jE-&-"sp&rm
Function: noun
Etymology: ultimately from New Latin angi- + Greek
sperma seed -- more at SPERM
: any of a class (Angiospermae) or division
(Magnoliophyta) of vascular plants (as magnolias, grasses,
oaks, roses, and daisies) that have the ovules and seeds
enclosed in an ovary, form the embryo and endosperm by
double fertilization, and typically have each flower
surrounded by a perianth composed of two sets of floral
envelopes comprising the calyx and corolla -- called also
flowering plant
- an·gio·sper·mous /"an-jE-&-'sp&r-m&s/ adjective
Main Entry: gym·no·sperm
Pronunciation: 'jim-n&-"sp&rm
Function: noun
Etymology: ultimately from Greek gymnos + sperma seed
-- more at SPERM
: any of a group of vascular plants that produce naked
seeds not enclosed in an ovary, that were formerly
considered a class (Gymnospermae) of seed plants, but that
are now considered polyphyletic in origin and divided into
several extinct divisions and four divisions with surviving
members typified by the cycadophytes, conifers, ginkgo,
and ephedras -- compare ANGIOSPERM
Wood & Lumber Basics
Moisture content of wood
Living trees moisture as a percentage of wood
substance can range from 30 to 200 percent.
 Water in trees exist as water or water vapor in
the cell lumens (cavities) or “bound” within the
cell walls.
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Wood & Lumber Basics
Green wood –where the cell walls are completely
saturated with water.
However
Green wood also contains additional water in the
lumens
Thus the term Green wood would mean freshly cut
trees dimensionally stable. As opposed to “green”
wood which is term used in grading lumber.
Wood & Lumber Basics
As we dry wood
Water leaves the cell lumens (cavities).
 However the cell walls are still saturated
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This is process where water remains in the cell
walls but not in the cell lumens or cavities. This
is referred to as the…..
Fiber Saturation Point
Wood & Lumber Basics
“Green” condition of lumber is where the lumber
is dried to a point below the fiber saturation point.
Equilibrium Moisture Content of lumber is where
the lumber is dried to where the wood is neither
gaining or losing moisture.
Once you reach equilibrium moisture content
(max. moisture content around 30%), the wood
can not take on any more water than the 30%.
Wood & Lumber Basics
Orthotropic Nature of Wood
Longitudinal (shrinks least)
 Tangential (shrinks most)
 Radial (Shrinks ½ of tangential)
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Thus wood is anisotropic material in that it does not
shrink equally.
Anisotropic causes us the most difficulty in working
with wood in combination as to how the wood is
milled or cut.
Foot note: Least known by today's craftsperson.
(½ of tangential)
(Shrinks most)
(Shrinks least)
Anisotropic
Milling
Very important for finish work
Wood Materials I
Board Foot
Standard measurement
 Based on Nominal Measurements
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(Remember nominal are not actual measurements)
Calculations
(thickness x width) /12” x Length X
Number of Pieces
Prices are quoted usually by the bf in thousand
board feet or M i.e. $456.00 / Mbf =.456 bf
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Wood is a multiple use building
material
Structural:
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Heavy timber framing
Light Framing
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Studs, Beams, Columns
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Standard Dimensions 2X4 2X6 etc
Manufactured Wood Products
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Glue-Laminated Beams
Wood Trussed Rafters
Exterior Cladding—plywood, sheathing, siding
Engineered Wood Products
Heavy Timber Framing
Wood plank and beam systems
A timber framed custom home
Concerns for the future
 Renewable Resources
 Old Growth Good
 Alternate Wood Products
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Our own material lab- patents on several manufactured
products
SIPs-Structural Insulated Panels
Manufactured Wood Products
Wood products glued and manufactured:
Better Strength
 Better Appearance—more dimensional stable
 More efficient use of wood products
 Can use smaller logs, wood not normally used
for lumber
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Manufactured Wood Products
Glue-Laminated Beams
 Wood Trussed Rafters
 Engineered Wood Products
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Exterior Cladding—plywood, sheathing, siding
Glu-Laminated Beams
(Glu-Lam)
Selected pieces of lumber glued together for
stronger beam
No seasoning cracking
Variety of sizes—long lengths possible
Easy availability
Variety of grades – visual
Wood Trussed Rafters
Trusses can be custom fabricated
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Heavy timber or light dimensional lumber
Truss span large area without intermediate
support
Types of trusses:
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Fan, scissors, Fink, Prat, etc.
Manufactured Wood Products
Manufactured lumber
Laminated decking
Veneer: thin-cut pieces
Slicing of veneers:
Rotary
 Plain
 Quarter
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Manufactured Wood Panels
Exterior ApplicationsSheathing: oriented strand (OSB)(waferboard)
sheathing
 Siding
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Interior Applications (particleboard)
Underlayment
 Cabinets: Overlay finish
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Plywood
Layers of veneer adhered together by glue, heat, pressure
Outside plies are face plies or face and back
Various number of plies: 3, 5, 6
 Effect stability and quality
Structural Plywood:
 Stamped, waterproof, exterior use or interior protected
Veneer Grading: face and back: A,B,C,D-(Ex. CDX)
Plywood Types
Structural Plywood
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Sheathing Roof, Wall, Floor- Exterior Glue
Exterior Use
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Siding, soffit
Cabinet Work
Finish Applications
Sheathing
Sub-floor
Underlayment
Wall Sheathing
Roofing
Box Beams
Engineered Wood Products
From fast-growing species such as aspen or
yellow poplar.
Wood Fiber
Lightweight
Minimum Waste
Compatible
Engineered Services
Product Types
TJI Joist ®(Wood I)
TJS Truss ®(Open Web)
Timber Strand®(LSL)
Microllam ®(LVL)
Parallam ®(PSL)
LSL-Laminated Strand Lumber
LVL-Laminated Veneer Lumber
PSL-Parallel Strand Lumber
Wood Materials I
Wood Panel Products
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Structural Wood Panels
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Three major categories
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Plywood Panels
Composite Panels – Core wood fibers (cabinet making)
Nonveneered Panels
• OSB Oriented Strand Board (best of nonveneers)
• Waferboard
• Particleboard
Wood Materials I
Plywood veneer grades (& Composite Panels)
(Know table and descriptions Table 1 pp. 89)
Add “N” grade
Better than “A” – specialized veneer
N
A
B
C
D
Best grade of face veneer
Worst grade of face veneer
N
Figure 3.32 & 3.32
(See handout)
Figure 3.3
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