Cm 2101- Ch. 3

Bark

Outermost protective layer of tree

Cambium Layer

New wood cells in tree

Sapwood

living cells that store and transport nutrients

Heartwood

dead cells that contribute to structural strength

pithe

first years growth, innermost layer

Softwoods

cone bearing trees
simple cells structure
N/A forests

Hardwoods

harvested around the world

FSC (Forest Stewardship Council)

only certified org. recognized by LEED certification

Sawing

first stage in lumber production

Plainsawn

growth rings parallel to wide face of board

Quartersawn

growth rings perpendicular to wider face of baord

Quartersawn

narrow spaced grain pattern on wider face

Ritesawn

angle of grain falls perfectly between plainsawn and quaretrsawn

Seasoning

second step in lumber production

Seasoning

drying lumber after it is sawn

Below 20%

Decay fungi cant live with MC content:

Below 30%

Wood shrinks after the MC content:

diff between tangential and radial shrinkage

causes distortions in lumber shape

EMC (Equilibrium Moisture Content)

when wood dries equal to air

15-19%

EMC content for exterior uses:

5-11%

EMC content for interior uses

Surfacing

third stage in lumber production

Surfacing

making lumber smooth and of perfect dimensions

framing lumber
(S4S)

type of surfacing on 4 sides

finishing lumber
(S4S or S2S)

four sides surfaced, or two sides and the other two left for woodworker

surfacing after seasoning
(S-Dry)

removes some drying distortions

surfacing after seasoning
(S-GRN)

more economical
better for wood that doesnt excessively distort

construction planking

unsurfaced
results in stronger plank bc no material is removed
more slip resistant

Structural Grading

way of rating lumber
higher ratings means less defects
performed visually or machines

Appearance Grading

way of rating lumber
for extent defects (knots)
always visually

Compression and Tension

Wood has good strength in:

less

Actual sizes are ___________ than normal sizes in lumber

3/4" x 3.5"
1.5" x 3.5"
1.5" x 9.25

Actual dimensions of a 1x4? 2x4? 2x10?

sometimes stronger and stiffer

Manufactured wood products are __________

Nominal
(by board foot)

In US, we price lumber by nominal or actual sizes?

Glue Laminated Wood

readily available wood that can be curved
uses high grade pieces ONLY at points of high stress

1. Laminated Strand Lumber and Oriented Strand Lumber
(LSL) (OSL)
2. Laminated Veneer Lumber (LVL)
3. Parallel Strand Lumber (PSL)

List in order by increasing strength the 3 structural composite lumber products?

beams and headers

what are structural composite lumber used for?

headers

short beams over openings

Wood-Plastic Composties

less stiff and greater thermal expansion than solid lumber

Plastic Lumber
(aka Wood plastic composite)

greater than 50% plastic

1. Plywood
2. Composite Panels
3. Oriented Strand Board
4. Particleboard
5. Fiberboard

List 5 Structural Wood Panels

4x8'
5/16"
1 and 1/8" thick

standard sizes of structural wood panels

sheathing and subflooring

Structural Wood Panels used for:

exposure 1

most common durability classification

1. Fire-retardent Wood
2. Preservative Treated Wood

2 types of chemically treated wood

1. Nails
2. Screws
3. Bolts

3 types of wood fasteners

Bolts

require pre-drilled hole

screws

_________ CAN require pilot holes

screws

require more time but hold better than nails

trusses

type of manufactured wood products
lightweight, joined with tooth plates

I-Joists
raw material

type of manufactured wood product
span further than solid lumber
uses less ___________

Panel Components

type of manufactured wood product
act structurally or attached to frame

1. Manufactured Homes (Mobile Homes)]
built to HUD standard
2. Modular Construction
factory

2 types of factory built housing
1. built to ________ ______
2. built in ______ and trucked to site