This document provides an overview of wood as a construction material, including its properties, types of wood, lumber production processes, engineered wood products, and fasteners. It discusses the qualities and composition of wood, softwoods and hardwoods, lumber grading and sizing, drying and surfacing methods, and common uses of wood in construction such as framing, sheathing, and trim. Engineered wood products like glulam, I-joists, and wood trusses are also summarized.

1. “ Crisscrossing light wood frame recalls Gothic and surrounding trees while lifting the mind skyward.” E. Fay Jones and Associates. Thorncrown Chapel Eureka Springs, Arkansas 1980 WOOD

2. Qualities of Wood Strong & Stiff Light Easily worked / shaped Fastened quickly & economically Recyclable Biodegradable Renewable Resource

3. Undesirable Characteristics of Wood Not perfectly straight nor precise Size & shape affected by moisture Contains growth defects Can spilt & warp Burns easily Decays Susceptible to Insect Damage

4. Tree Composition Bark Cambium Sapwood Heartwood Pith

5. Softwoods : Conifer Trees (pine, fir, spruce) for framing and sheathing

6. Hardwoods - Deciduous trees (leaf trees) Like maple, oak ash, beech, birch Used for Flooring, moldings, furniture

7. Tree Cells Primarily Hollow, Cylindrical Cells Axis running parallel to the tree (grain direction) Tough Cellulose bound by Lignin Impacts the properties of wood

8. Tree Growth Springwood (earlywood) Faster growth Cells larger and less dense Summerwood (latewood) Slower growth Cells smaller and denser

9. Types of Trees / Woods Oak Poplar Pine

10. Construction Uses for Wood Structural Framing Subfloors and Roof Sheathing Siding - Structural & Exposed Finish cabinetry and Trim

11. Lumber Production - Sawing Plain Sawing Maximum Yield Varying grain pattern Common use - Framing lumber

12. Lumber Production - Sawing Quarter Sawing Perpendicular to annual rings Less yield, but consistent grain pattern Improved wearing quality, less distortion

13. Typical Sawing Method

14. Lumber Drying Drying Methods Air Kiln Drying Effects Shrinkage Reduced weight Increase of strength and stiffness More dimensional stable

15. Differential Shrinkage (between radial & tangential) during drying can cause distortions

16. Lumber Surfacing Purpose; Smooth Dimensional precision Designations; S2S, S4S Surfacing typically performed before or after drying? Rough sawn (not surfaced) S4S

17. Lumber Defects Growth defects Knots & knot holes Decay and/or insect damage Manufacturing Defects Splits & checks Crook, bow, Cup, and/or twist

19. Lumber Grade & Species Graded by: Strength & Stiffness (Structural Lumber), or Appearance (Finish Lumber) Lumber sold by - Species and Grade Better Grade  Higher price Scarce or Higher Quality Species  Higher price

20. Spruce, Fir, or Pine Stud Surfaced Dry No 2 Lumber Kiln Dried (19% moisture)

21. Lumber Thickness and Width - NOMINAL Thickness < 2 inches - Boards 2 to 4 in. - Dimension Lumber = to or > 5 inches - Timbers Widths Framing Lumber - 2, 4, 6, 8, 10, 12 inches Finish /lumber - 1 inch (typ.)

22. Lumber Thickness and Width - ACTUAL Nominal not equal to Actual dimensions Lumber SAWN Close to Nominal Then dried and surfaced Up to 6 inches - actual is 1/2 inch less Greater than 6 inches - actual is 3/4 inch less

23. Lumber Lengths Typically; Two (2) foot increments Sizes; 8’, 10’, 12’, 14’, & 16’ (longer available) Exceptions; 93 inch studs Special order lengths

24. Lumber Pricing Factors Species Grade (& drying process) Lumber Size

25. Lumber Pricing Unit - Board Feet One board foot = 1 inch X 12 inch X 1 foot Calculation based upon Nominal dimensions # of board feet = [(thickness” X width”) / 12] X length’ Example; 2x8 that is 10 feet long [(2x8)/12] X 10 = 13.33 board feet (bf)

26. Laminated Wood ( Glulam ) Lamination Process Why Laminate? Create a size not available naturally Create Shapes Improve Quality

29. Structural Composite Lumber (PSL)

31. Wood Panel Products Why Panelize? More “controlled” product Efficient use of forest products Increase labor productivity Types Plywood panels Composite panels Nonveneered panels

32. Veneered Panels - Plywood Thin layers of veneer glued together Odd number of veneers Alternating direction of veneers Face veneers parallel Size: 4’x8’ panels Thickness: ¼” to 1”

33. Veneer Grades Based on the smoothness & integrity of the veneers Classifications; A, B, C (plugged), C, D Price Variances C Grade C Plugged A Grade

34. Non-veneered Panels Oriented Strand Board (OSB) Waferboard Particleboard Fiberboard Particleboard Fiberboard

35. Oriented Strand Board (OSB) Long strand like wood particles Alternate grain orientation (3-5 layers) Compressed / glued Strongest of the Non-veneered Uses; Sheathing for floor, roofs, & siding

36. Waferboard & Particleboard Waferboard Large wafer-like particles - No orientation Uses; Low moisture areas Particleboard Small wood particles No orientation Uses; Low moisture areas

37. Panel Standards & Grading Established by American Plywood Association (APA) Standards based on; Structural adequacy Dimensional Stability Durability of Adhesive

38. Structural Ratings Specified by Thickness or Span Rating Span Rating Grade Stamp For veneered & nonveneered Long dimension perpendicular to the support

39. Exposure Durability Classifications Exposure Durability Exterior - siding or continuous exposure Exposure I; waterproof glue but lower quality veneers Exposure II; protected environments & minimum wetting

40. PRESERVATIVE-TREATED WOOD Waterborne Preservatives ACQ (alkaline copper quat CA (copper azole) SBX (sodium borates) CCA (copper, chromate, arsenic) Creosote Distillate of coal tar Oil-borne Penta(chlorophenol)

41. Wood Polymer Composite Planks proprietary name: TREX Advantages: Decay Resistance Easy Workability

42. Wood Fasteners Nails Wood & Lag Screws Bolts Toothed Plates Sheet Metal & Metal Framing Devices Machine Driven Staples & Nails Adhesives

43. Nails Sharpened metal pins Installation: Hammer or mechanical nail gun Common Nails Finish Nails Other types

44. 16d Galvanized 16d Sinker Deformed Shank 10d Galv. Spiral Finish Nail Roofing Nail (far right)

45. Nails Size - Measured in pennies Coatings Bright/ Plain uncoated steel Galvanized Corrosion-resistant Resin/Vinyl

46. Anchorage Face, End, or Toe

47. Machine Driven Nails & Staples Nail Guns, Staple guns Pneumatic (or electric) Pre-packaged fasteners (collated nails) Improved Productivity Used in many applications Power actuated fasteners Battery Powered Electric Nailer Collated Nails

48. Wood Screws Head type Sizing - Gauge & Length Installation Holding power Uses Deck Screws Types of ‘Heads’

49. Lag & Drywall Screws Lag Screws Large screws Square or octagonal head Installed w/ wrench Drywall screws Used to attach drywall

50. Bolts Heavier structural connections Sizes Types Machine Carriage Washers

51. Toothed Plates Sheet metal plate w/ numerous teeth Used with roof & floor trusses Pressed into members Very effective fasteners

52. Sheet Metal Framing Devices Light Wood Framing Joist Hangers Framing anchors Angle anchors Rafter anchor Heavy Timber or Laminated Framing

53. Adhesives Widely used in the manufacture of wood products Wood panels Laminated wood Cabinetry On Site Uses Sheathing

54. Engineered Wood Trusses Wood I-Joists Beams (gluelams) Panel Components

55. Trusses Types of Trusses - Floor & Roof Floor Trusses Roof Trusses

57. Trusses (cont.) Where and How Built? Most factory built (pre-engineered) Most 2X4 or 2X6 w/ toothed fasteners Order how? Span Loads Pitch (roof) Overhang

58. I-Joists Uses Sizes Composition Cost

59. Why Use Trusses or I-Joists? Less material (less weight) More efficient use of wood Increased Span Increased dimensional stability Installation savings (labor)

60. Sustainability in Wood Construction Only major renewable structural material Forestry Practices Sustainable forestry Clearcutting & replanting Mill Practices – Lumber Recovery Factor (LRF) Transportation Embodies Energy Content