1. Wood

2. Terminology and Classification
The terms wood, lumber, and timber are often used
interchangeably, but each term has a distinct meaning.
Wood Hard fibrous substance lying beneath the bark of trees.
Lumber Wood that has been sawn into construction members.
Timber Lumber that is five inches or larger in its least dimension.

3. Terminology and Classification
Wood is classified as softwood or hardwood depending on the type of tree it originates from.
Softwoods, such as pine, fir, and spruce, come from needle-leaved conifers, which are evergreen
Hardwoods, such as maple, oak, and sycamore, come from broad-leaved deciduous trees, which shed their leaves annually.
The important difference between softwoods and hardwoods is botanical, which refers to the cellular structure of the two groups. Most hardwoods are in fact harder than softwoods; however balsa wood, one of the softest woods known is actually a hardwood.

4. Characteristics of Wood
Wood consists of approximately 70% cellulose and 18% to 28% lignin, which is the adhesive imparting strength to the wood.
The remainder is made up of minerals and extractives, which give wood its color, odor, and resistance to decay.

5. Cutting and Sawing Lumber
Lumber can be cut from a log in two different ways: tangent to the annual rings, called plain-sawed in hardwoods and flat-grained or slain-grained in softwoods.
Lumber cut radially to the annual rings is called quarter-sawed in hardwoods, and edge-grained or vertical-grained in softwoods.
Lumber is classified as quarter-sawed if the grain is 45 degrees to 90 degrees to the wide face and plain-sawed if the grain is 0 degrees to 45 degrees to the wide face.

6. PLAIN SAWNED LUMBER AND TIMBER
QUARTER SAWNED
LUMBER AND TIMBER

7. Cutting and Sawing Lumber
Characteristics of plain-sawed lumber include:
Distinct grain pattern,
May twist, cup, or wear unevenly,
Tends to have a raised grain,
Shrinks and swells more in width, less in thickness,
Less waste in cutting, and therefore less expensive.

8. Cutting and Sawing Lumber
Characteristics of quarter-sawed lumber include:
Relatively even grain pattern,
Wears evenly with less warpage,
Shrinks and swells more in thickness, less in width,
More waste in cutting and therefore more costly.

9. Shrinkage, distortion, and warpage of lumber depends partially on the way lumber is cut from a tree. Wood shrinks most in the direction of the annual growth rings (tangentially); less across these rings (radially); and very little parallel to the grain (longitudinally).

10. shrinkage stiffness strength
Seasoning of Wood
shrinkage stiffness strength
As moisture content in the cells of wood changes, particularly as it dries out, wood members can change shape if the change moisture content is not done in controlled conditions. As wood dries out the amount of shrinkage differs in various directions.
Shrinkage is limited to parallel to the grain of the wood. It is greatest when measured in a tangent to the growth rings. The amount of shrinkage along the radius of the wood is less than that tangentially. Depending on where in the log the member is cut from, uncontrolled drying can cause wood members to exhibit unusual shapes as shown here in this exaggerated illustration.

11. Seasoning of Wood shrinkage stiffness strength appearance
Making wood suitable for construction involved more than simply cutting down a tree and sawing the wood to size. Wood in a tree is green, that is, contains a large amount of water. If green lumber is used in construction, it will shrink as it dries out.
Making wood suitable for construction involved more than simply cutting down a tree and sawing the wood to size. Wood in a tree is green, that is, contains a large amount of water. If green lumber is used in construction, it will shrink as it dries out.
To minimize shrinkage, lumber should be seasoned dried before use to between10% to 20% moisture content. This can be accomplished by air drying, which takes several weeks or kiln drying.which takes only a few days. Over 90% of lumber is kiln dried
Framing lumber is considered seasoned if its moisture content is 19% or less.
An 18’ 2x10 loses approx 5 gallons of water
Hardwood Inc.Tour Tuesday, Sept. 6, 2011

12. Drying Lumber Video 1:39 minutes

13. damaged by insects decayed by fungus
Wood Defects
Variety of defects affect the
strength
appearance
use
and grading of lumber.
Defects may be natural.
damaged by insects decayed by fungus
and of course, destroyed by fire.
or caused by manufacturing

14. Wood Defects NATURAL DEFECTS:
Knot: branch embedded in a tree and cut through manufacturing.
Shake: pitted area sometimes found in cedar and cypress.
Pitched Pocket: opening between growth rings and containing resin.

15. Wood Defects MANUFACTURED DEFECTS:
Check: lengthwise grain separation caused by seasoning.
Split: lengthwise separation of wood extending from one face to another.
Wane: lack of wood on the edge or corner.
Warp: shrinkage distortion of a plane surface, includes---bow, crook, cup and twist.

16. Pressure Treating Lumber Video 1:01 minutes
Wood can be damaged by insects and decayed by fungus
Pressure Treating Lumber Video 1:01 minutes

17. Standardized terms and dimensions

18. Standardize Dimensions – Nominal Verse Actual size

19. Plywood Veneer Cutting
forms random pattern
forms repeating pattern
forms parallel pattern

20. Sample Plain Sliced Patterns
Plain sliced Cherry, Walnut, Teak. Red Oak

21. Sample Quarter Cut Patterns
This is the perception is of what a quarter cut panel will look like. Quarter Anigre, Zebrawood, Rosewood and Quartered White Oak.
Note in this photo the “flake”

22. Miscellaneous Panels running match book matching balance match
slip matching
random matching
center match

23. Book Match Every other veneer turned over
Veneer joints match, creating symmetrical pattern
Most common
Used with plain slicing most
Book Match, the most common method of matching veneer leaves and most suitable for flat cut or plain sliced veneer. Every other leaf is turned over creating a mirror effect. This is most commonly used in architectural panels or wall applications, especially for wood veneer that has a lot of grain.

24. Slip Match Leaves “slipped” off in sequence without turning
Repeating grain - joints don’t match
Often used with quartered or rift veneers
Slip Match is most suitable for quarter or rift cut veneer. The same side of the veneer leaf is exposed. Slip match is primarily used for quartered veneers. Used to eliminate the barber pole light/dark effect.

25. Random Match Veneer book broken Leaf sequence destroyed on purpose
Appearance of boards
Casual or Rustic
More difficult than Book or Slip

26. T = Tension C= Compression
Wood is generally stronger in compression than tension. Unlike other materials, the strength of wood is not the same in every direction for tension and compression.
Wood is stronger when the load is applied parallel to the grain than perpendicular to the grain. In fact, the strength of wood in tension perpendicular to the grain is so low that this type of loading can easily cause the wood to split.
For shear, wood is very strong perpendicular to the grain and relatively weak parallel to the grain. Therefore, horizontal shear stress (parallel to the grain) is often a design consideration, while vertical shear stress (perpendicular to the grain) is not.

27. Wood Species
What is Southern Pine? Video 1:00 minute

28. Wood Species Guide

29. Example of what we will see at tour: Purpleheart Lumber
Sources Includes species in tropical regions of Central America and South America. Appearance Generally straight grained, sometimes interlocked, with a fine even texture. Creamy white sapwood and vibrant purple heartwood that turns to dark-purplish brown with exposure to light.
Physical Properties Very heavy, hard, strong, and stiff with good decay resistance and stability in service. Steam-bends moderately well.

31. Structural Strength of Wood
Species ( Fir, Hemlock, Pine, etc)
Grade
Direction of Grain ( parallel or perpendicular)
Size and Shape
Moisture Content

34. Definition of Moisture Content
Weight of water compared to the weight of dry wood
Formula for Moisture Content
Weight of water as % of wt. of dry wood

35. What is considered an acceptable moisture content of framing lumber?

36. What is considered an acceptable moisture content of framing lumber?
19%
Weight of the water in the wood is 19% of the weight of the dry wood.
If the wood was 100 pounds dry, then it has 19 pounds of water in it.

37. Wood

39. Engineered Wood Products
Particle Board
MDF
OSB
LVL
LSL
Masonite
Plywood
Glulam
Plastic Lumber
Wood I-Beams
Wood Trusses
Structural Wood Panels
plywood
composite panel
non-veneered panel

40. Particle Board manufactured from wood particles, such as wood chips, sawmill shavings, or even saw dust. Made with larger pieces of wood than used to make MDF

41. Oriented Strand Board (OSB) sometimes called waferboard

42. Oriented Strand Board (OSB)

43. O S B Video 1:08 minutes

44. Medium Density Fiberboard (MDF) Combination of softwood fibers, wax & resin. Stronger than particle board

45. Laminate Strand Lumber (LSL) Made up of strands of lumber instead of veneers

46. Laminated Veneer Lumber (LVL) LVL is made by gluing sheets of veneer together. Unlike plywood, here all veneer layers are going in the same direction. Wide panels are manufactured to the thickness of the desired lumber. The panels are ripped into lumber of nominal width.

47. Masonite Type of hardboard invented by William H. Mason
Masonite Type of hardboard invented by William H. Mason.[1] It is formed using the Mason method, using wooden chips and blasting them into long fibers with steam and then forming them into boards. The boards are then pressed and heated to form the finished boards. No glue or other material is added.

48. Plywood made from thin sheets of wood veneer, called plies or veneers, layered in opposite directions

49. What is hardwood plywood?
Three or more layers of wood or wood products laminated into a single sheet
FACES; Outside decorative veneers
CORE; MDF, PB, VC, Combos

50. Construction balance Three is minimum Always Odd 3, 5, 7, 9……
Panel Balance a Must!

51. Plywood Video minutes

52. Plywood is classified as interior or exterior depending on the type of adhesive used: moisture-resistant for interior use, and water-proof for exterior use. Plywood used in construction is primarily softwood. Plywood used for interior millwork or cabinetry is usually hardwood. .

53. Plywood Plywood is classified as interior or exterior depending on the type of adhesive used: moisture-resistant for interior use, and water-proof for exterior use. Plywood used in construction is primarily softwood. Plywood used for interior millwork or cabinetry is usually hardwood. Plywood is graded according to quality of the veneer: A Best D poorest.

54. Second number -maximum recommended span use as subflooring.
Span Rating
First number - maximum recommended roof span in inches if used as roof sheathing
Second number -maximum recommended span use as subflooring.
For example, a panel identified as 32/16 can be used as roof sheathing over rafters spaced 32 inches on center or as subflooring over joists spaced 16 inches on center.

55. Glued Laminated Lumber (Glulam) These beams are made by gluing many boards together to form a structural member bigger than the trees from which the board were sawn. Since the load is carried by the material in the top and bottom faces and the middle only has to resist shear, high quality lumber is used in the top and bottom while medium grade lumber is used in the center. (gluelam or glulam) Joints between boards are typically scarf or finger joints.

56. Glue Laminated Construction
Curves that remain in one plane are much easier to construct than
compound curves (a dome). A dome is likely to be segmented curves.

58. Glulam Video 2:04 minutes

59. RPL Recycled Plastic Lumber Lumber-like products with a plastic content of 50% or more. Higher expansion & contraction with temperature changes. Less structural strength

60. I-Beams & I-Joists Veneer lumber is used for the flanges and plywood or OSB is used for the web to resist shear.

61. I - Joist Video 2:48 minutes

62. Wood Trusses
Fink Truss

63. Wood Siding

64. 
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