Selecting Selecting LumberLumber

Interest ApproachInterest Approach

Look at the piece of wood you are Look at the piece of wood you are given. Write down as many given. Write down as many observations as possible.observations as possible.

Measure the dimensions of the Measure the dimensions of the piece of wood. Write them down piece of wood. Write them down with your observations.with your observations.

Interest ApproachInterest Approach

What happens between cutting What happens between cutting down a tree and you buying the down a tree and you buying the wood as lumber?wood as lumber?

How is lumber graded and stored? How is lumber graded and stored? How can you determine which type How can you determine which type

of lumber to buy? of lumber to buy?

Problem:Problem:

How are lumber and other How are lumber and other wood products produced wood products produced

and processed?and processed?

Lumber Production and ProcessingLumber Production and Processing

trees are cut down trees are cut down transported to the sawmill transported to the sawmill logs are soaked until sawing timelogs are soaked until sawing time

prevents checking, cracking, and prevents checking, cracking, and warpingwarping

bark is removed bark is removed plain-sawed or quarter-sawedplain-sawed or quarter-sawed

Plain-SawingPlain-Sawing

Cutting the log on a Cutting the log on a tangent to the tangent to the growth ringsgrowth rings faster faster less waste less waste lower cost lumberlower cost lumber used in buildings used in buildings

Quarter-Sawed LumberQuarter-Sawed Lumber

Cutting the log perpendicular to the Cutting the log perpendicular to the growth ringsgrowth rings less likely to warp, shrink, and swellless likely to warp, shrink, and swell used to make furnitureused to make furniture

Drying LumberDrying Lumber

Green lumberGreen lumber Freshly cut lumber with 20 percent or Freshly cut lumber with 20 percent or

more moisture.more moisture. SeasoningSeasoning

Process of drying lumber to the point Process of drying lumber to the point where it is ready to use. where it is ready to use.

Drying LumberDrying Lumber

Air dryingAir drying Set outside to drySet outside to dry Takes 1-3 monthsTakes 1-3 months Moisture content to 15% Moisture content to 15%

Kiln-dried Kiln-dried uses a large oven or kiln to dry uses a large oven or kiln to dry Moisture content to 6% to 12%Moisture content to 6% to 12%

After DryingAfter Drying

Run through a planer to make it Run through a planer to make it smooth and dimensionalsmooth and dimensional

Plywood:Plywood:

a series of layers (3, 5, or 7) glued a series of layers (3, 5, or 7) glued together with the grains arranged at together with the grains arranged at right angles to each other to form a right angles to each other to form a 4×8 sheet4×8 sheet strength is maximizedstrength is maximized

Particle BoardParticle Board

4×8 sheet made by gluing wood 4×8 sheet made by gluing wood chips, splinter, and sawdust chips, splinter, and sawdust togethertogether used under countertops and in some used under countertops and in some

furniturefurniture cheaper cheaper warps quickly when it gets wetwarps quickly when it gets wet

Waferboard (OSB or Chip board)Waferboard (OSB or Chip board)

gluing wood chips to form 4×8 gluing wood chips to form 4×8 sheetssheets cheaper cheaper more water resistantmore water resistant Used in roof sheathing and Used in roof sheathing and

subflooringsubflooring

PanelingPaneling

1/8 or ¼ inch sheet of wood or 1/8 or ¼ inch sheet of wood or hardboard with a wood grain hardboard with a wood grain surfacesurface Cheap paneling may be wood with Cheap paneling may be wood with

wood grain contact paper on the wood grain contact paper on the surface.surface.

VeneerVeneer

Thin layer of material that is glued Thin layer of material that is glued to an inferior quality material. to an inferior quality material.

low cost furniture is often particle low cost furniture is often particle board with a veneer wood grain board with a veneer wood grain surface layersurface layer

Problem:Problem:

How is lumber graded and How is lumber graded and selected for use?selected for use?

Lumber Grading and Selection Lumber Grading and Selection

Wood for lumber is divided into two Wood for lumber is divided into two broad categories, “softwood” and broad categories, “softwood” and “hardwood”. “hardwood”. Refers to the type of tree they come Refers to the type of tree they come

fromfrom

HardwoodHardwood

lumber cut from broad-leaved lumber cut from broad-leaved (deciduous) trees that drop their (deciduous) trees that drop their leaves in the fallleaves in the fall Oak, maple, cherryOak, maple, cherry Fine furnitureFine furniture

SoftwoodSoftwood

Lumber cut from coniferous (cone-Lumber cut from coniferous (cone-bearing) evergreen trees with bearing) evergreen trees with needle-like leavesneedle-like leaves construction lumberconstruction lumber

Softwood GradingSoftwood Grading

Softwood grading is based on:Softwood grading is based on: Appearance,Appearance, Strength, or Strength, or Combination of the two. Combination of the two.

Softwood GradingSoftwood Grading

Defects which can affect both Defects which can affect both appearance and strength include:appearance and strength include: knots,knots, checks, checks, splits,splits, decay,decay, stains, stains, insect holesinsect holes

Matching Lumber to jobMatching Lumber to job

Use the lowest quality of lumber Use the lowest quality of lumber suitable for the purpose. suitable for the purpose.

Requires a knowledge of the Requires a knowledge of the characteristics of each species of characteristics of each species of wood.wood.

Properties of WoodProperties of Wood Good understanding of wood Good understanding of wood

properties is essential for intelligent properties is essential for intelligent lumber selection.lumber selection.

Properties Include:Properties Include: Hardness Hardness Bending strength Bending strength Stiffness Stiffness Compression strength Compression strength ToughnessToughness

Problem:Problem:

How is lumber sized, How is lumber sized, purchased, and stored?purchased, and stored?

Worked lumberWorked lumber

Wood that has beenWood that has been Shaped (trim)Shaped (trim) Matched (tongue-and-groove)Matched (tongue-and-groove) Patterned (molding)Patterned (molding)

Actual vs. Nominal DimensionsActual vs. Nominal Dimensions

The difference between nominal The difference between nominal and actual (dressed) dimensions of and actual (dressed) dimensions of lumber is the result of:lumber is the result of: Planing,Planing, Shrinkage that occurs during drying. Shrinkage that occurs during drying.

Actual vs. Nominal DimensionsActual vs. Nominal Dimensions

Nominal dimensions (2×4, 1×6, etc.) Nominal dimensions (2×4, 1×6, etc.) are used when ordering lumberare used when ordering lumber

Project planner uses the actual Project planner uses the actual planed dimensions (¾×3½ , planed dimensions (¾×3½ , 1½×7¼, etc.) to determine the 1½×7¼, etc.) to determine the number and length of boards number and length of boards needed needed

Actual vs. Nominal DimensionsActual vs. Nominal Dimensions

Softwood nominal widths are 2, 3, Softwood nominal widths are 2, 3, 4, 6, 8, 10, and 12 inch. 4, 6, 8, 10, and 12 inch.

Standard available lengths are even Standard available lengths are even feet from 6 to 20. feet from 6 to 20.

Actual vs. Nominal DimensionsActual vs. Nominal Dimensions

To find the actual width for nominal To find the actual width for nominal widths of 6 inches or less drop ½ widths of 6 inches or less drop ½ inch. inch.

For nominal widths of over 6 inches For nominal widths of over 6 inches drop ¾ inch to find the actual width.drop ¾ inch to find the actual width.

Linear feetLinear feet

length in feet without regard to length in feet without regard to thickness or widththickness or width Thickness of these sheets vary through Thickness of these sheets vary through

a range of ¼, 3/8, ½, 5/8, to ¾ incha range of ¼, 3/8, ½, 5/8, to ¾ inch Generally sold by the 4×8 sheetGenerally sold by the 4×8 sheet

Plywood, Plywood, Particle board, Particle board, Paneling are generally sold by the 4×8 sheet. Paneling are generally sold by the 4×8 sheet.

Actual vs. Nominal DimensionsActual vs. Nominal Dimensions

All of these materials are priced All of these materials are priced either by the square foot or by the either by the square foot or by the sheet. sheet.

Other building materials, such as Other building materials, such as roofing and siding, are sold by “the roofing and siding, are sold by “the square”. square”. ““The square” actually means 100 The square” actually means 100

square feet of surface coverage.square feet of surface coverage.

Ordering LumberOrdering Lumber Do not order large quantities of Do not order large quantities of

lumber long in advancelumber long in advance When storing lumber, care should be When storing lumber, care should be

taken to avoid:taken to avoid: Warping,Warping, Staining, and Staining, and Moisture absorption problems.Moisture absorption problems.

(Picture Courtesy, Interstate Publishers, Inc.)