SELECTING WOOD & LUMBER

1. SELECTING WOOD & LUMBER Mandi Bañales April 2001 Cal Poly San Luis Obispo Modified by Georgia Agricultural Education Curriculum Office July, 2002

2. KINDS OF WOOD • Softwood comes from needle leaf, evergreen trees called conifers • Hardwood comes from broadleaf trees that lose their leaves each fall season, called deciduous trees. Kinds of Woods

3. Softwood types

4. White pine – shelving, interior finish, exterior trim, and door frames Yellow pine – benches, stairs, where semi-hard surface is desired Fir – framing members, siding, sheathing, and gates Redwood – posts, fences, patios, and siding Cedar – fence posts, sills, and shingles Spruce – aviation and musical instruments Uses of Softwood Types

5. HARDWOOD TYPES

6. Hardwood Identification BIRCH OAK WALNUT MAHAGONY MAPLE

7. Oak - used in floors, interior finish, barrels, furniture Walnut – used for fine furniture, boat building, clock cases Maple – used for floors, interior finish, furniture, and guitar necks Mahogany – is used for fine furniture, boat interiors, pianos, Birch – used for surface veneer on cabinets and doors, Furniture, high-grade joinery, high-grade plywood Uses of Hardwood Types

8. Log Cutting Method #1 • Slash sawing cuts a log so that the annular rings form an angle of less than 45 degrees with the surface of the lumber. • Softwood lumber cut in this fashion is referred to as flat-grained • Hardwood lumber cut in this fashion is referred to as plain-sawed

9. Quarter sawing cuts a log so that the annular rings form an angle of more than 45 degrees with the surface of the lumber. Softwood lumber cut in this fashion is referred to as edge-grained Hardwood lumber cut in this fashion is referred to as quarter-sawed Log Cutting Method #2

10. FINISHES • Rough lumber comes directly from the sawmill unplaned and varying in dimensions from piece to piece • S2S - lumber surfaced on two sides-all pieces to have the same thickness, but varying widths • S4S – Lumber surfaced on four sides allowing exact dimension from piece to piece.

11. Special Notes for FINISHES • THE ACTUAL SIZES ARE ½ INCH LESS THAN THE NOMINAL SIZES! Example: the actual size of a 2 x 4 is Only1 1/2” x 3 1/2”

12. THE BASIS OF LUMBER GRADES APPEARANCE AND SOUNDNESS OF WOOD

13. Examples of Lumber Grades. These would be on the wood at time of purchase.

14. DEFECT VS. BLEMISH • A Lumber defect is an irregularity in or on the wood that reduces its strength, durability, or usefulness • A Lumber blemish is a defect that impairs only the wood’s appearance

15. Knots Holes Splits Shakes Pitch pockets Honey combing Wane Decay Blue Stain Warp Common Lumber Defects

16. Select – Grades A & B suitable for natural finishes Grades C & D are suitable for paint finishes Common – Common #1, 2, and 3 are suitable for use without waste Common # 4 and 5 are suitable for use permitting waste Basic Lumber Grades

17. PLYWOOD GRADES

18. Factors to Consider when Selecting Lumber • Quality construction does not require that all the lumber be of the best grade • Several grades of lumber may be appropriate in a single structure • Good economical construction requires the proper use of the lowest grade lumber suitable for the purpose