Taxonomy of Wood Products

Engineered Wood Products

WOOD

Composites Solid Wood Pulp and Paper

PanelsEngineered

LumberComposites

SoftwoodLumber

Wood/Non-wood

Wood Based

Wood/Cement

Wood/Plastic

Particleboard

MDF

Plywood

OSB

LVL

OSL

Glulam

HardwoodTreatedGlued

Finger joined

Edge glued

Pulp Paper

Mechanical

Chemical

Boards

Dimension

Timber

MSRSecondary

Wood Products

Furniture

Millwork & Factory-built Housing

Windows & Doors

Cabinets

Wood Products Taxonomy

Engineered WoodProducts

I-Beams

Trusses

CLT

Solid wood products Engineered wood products

Choice of Wood Products

• Relative strength rating ?

(a) 75-85

or

(b) 50-100

• Product composition ?

(a) one large piece of solid wood

or

(b) smaller pieces wood glued together

4

Engineered wood products - benefits compared to solid wood

• More reliable

• Higher strength ratings

• Larger dimensions possible

• Smaller trees can be utilized

Variability in wood products

frequency

strength

Solid wood

6

Variability in wood products

frequency

strength

Solid woodlower 5th percentile

mean

7

÷ safety factors

allowable design stress

Variability in wood products

frequency

strength

Solid woodlower 5th percentile

mean

÷ safety factors

allowable design stress

allowable design stress

lower 5th percentile

÷ safety factors

Wood composite A

mean

8

Variability in wood products

frequency

strength

Solid wood

lower 5th percentile

÷ safety factors

allowable design stress

allowable design stress

lower 5th percentile

÷ safety factors

mean

Wood composite B

mean

9

Solid wood vs. Engineered lumber composite

Which is “stronger”?

strength

frequency

“Stronger” = “Can accept higher design loads”

10

Solid wood

Wood composite

Reduction of natural variability

Initial source ofsolid wood

Wood source reduced to designed elements

Elements combined into more consistent engineered products

Strategic placement of elements

11

Strands

Veneer sheets

Veneer strips Lamstock

Wood Elements

WOOD

Composites Solid Wood Pulp and Paper

PanelsEngineered

LumberComposites

SoftwoodLumber

Wood/Non-wood

Wood Based

Wood/Cement

Wood/Plastic

Particleboard

MDF

Plywood

OSB

LVL

OSL

Glulam

HardwoodTreatedGlued

Finger joined

Edge glued

Pulp Paper

Mechanical

Chemical

Boards

Dimension

Timber

MSRSecondary

Wood Products

Furniture

Millwork & Factory-built Housing

Windows & Doors

Cabinets

Wood Products Taxonomy

Laminated Veneer Lumber

Elements: Sheets of wooden veneer(1/8-1/10” thick, 2’ wide, 8’ long)

Product Width 1½ - 3½ inchesDimensions: Depth up to 24 inches

Length up to 80 feet

Applications: Beams, headers, I-beam flange14

LVL – manufacturing overview

1

2

345

6

Laminated Veneer Lumber (LVL)

Softwood veneers produced as in plywood production Veneers graded prior to assembly Higher quality veneers are placed on the outsides Veneers glued with grain running parallel to each other

LVL used on flat (I-beam flanges) or on edge (beams,

headers)16

Edge

Flat

LVL – end use dimensions

• Width 1 ½ in., 1 ¾ in., and 3 ½ in.

• Depth up to 24 in.

• Length up to 24m

Laminated Veneer LumberVariability is reducedin one plane.

Solid woodVariability is at its greatest level.

Reduction of natural variability

• Defects in veneer can be removed or dispersed • Variability is reduced• Yield of veneer from logs is higher than yield of solid

lumber18

Laminated Veneer Lumber

LVL beamLVL in I-beam

19

LVL - headers

Glue Laminated Timber (Glulam)

Elements: “Lamstock”, high quality dimension lumber(1½” thick, up to 10” wide, up to 20’ long)

Product Width 3½-14 inchesDimensions: Depth up to 8 feet

Length up to 140 feet

Applications: Beams, columns, arches, trusses21

Individuallaminations

Finger joint

Centre for Advanced Wood Processing

Glulam - laminations

Top and bottom laminations might be different species

Finger joints along laminations

Total dimensions = 5.25” x 17.5”

(This is not a commercial sample)

Multiple laminations

Mulitple pieces per width of lamination

Glulam – build up of column

Glue Laminated Lumber (Glulam)

Individual lamstock elements are stress-rated prior to beam fabrication Stiffer elements are placed in more critical locations in member Very large dimensions possible

25

Glue Laminated Lumber (Glulam)

Curved members can be created

Tighter curves require thinner laminations

Architectural as well as structural

26

Glulam - Columns, Beams and Rafters

27

Glulam - Roof Beams

28

Glulam - Curved Roof Beams

29

Glulam - Curved Bridges

30

Glulam – curved members