1. Chapter 3
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 PROTECTIVE LAYER
OUTSIDE IS DEAD - INSIDE ALIVE
Cambium
VERY THIN
CREATES NEW CELLS
Sapwood
STORE NUTRIENTS & TRANSMITS SAP
THICK - LIVING
Heartwood
DEAD WOOD
PROVIDES STRUCTURAL STABILITY
Pith
EARLY YEARS GROWTH
SMALL - WEAK

5. Tree Cells Primarily Hollow, Cylindrical Cells
Axis running parallel to the tree (grain direction)
Tough Cellulose bound by Lignin
Impacts the properties of wood
Primarily Hollow, Cylindrical Cells - “TRACHEIDS”
Axis running parallel to the tree
Tough Cellulose bond by Lignin
IMAGINE A GROUP OF STRAWS
Impact on the properties of wood
PARALLEL WITH GRAIN (TUBE) STRONG
PERPENDICULAR - WEAK

6. Types of Trees / Woods Oak Pine Poplar Oak Pine Poplar
Softwoods - Coniferous Trees
“SOFT” OR “HARD” NOT NECESSARILY LITERALLY
SIMPLE MICROSTRUCTURE
COARSE UNINTERESTING GRAIN
PINE, SPRUCE, FIR, CEDAR
MOST OF THE LUMBER USED IN BUILDING
WHY???
GROWS FASTER, MORE PLENTIFUL, MORE ECONOMICAL
Hardwoods - Broad leafed trees
MORE COMPLEX STRUCTURE
BEAUTIFUL GRAIN PATTERNS
PRIMARILY - FINE CABINETRY & DOORS, TRIMS / ACCENTS
OAK, POPULAR, WALNUT, MAPLE
Oak
Pine
Oak
Pine
Poplar
Poplar

7. Construction Uses for Wood
Structural Framing
Subfloors and Roof Sheathing
Siding - Structural & Exposed
Finish cabinetry and Trim
Structural Framing
GENERALLY PINE, FIR OR SPRUCE
Subfloors and Roof decking
GENERALLY WOOD PANELS
Siding - Structural & Exposed
STRUCTURAL - OFTEN WOOD PANELS
EXPOSED - NATURALLY DECAY RESISTANT OR TREATED
CEDAR, CYPRESS
Finish cabinetry and Trim
PAINTED OR LAMINATED - PANELS OR SOFTWOODS
“EXPOSED”/ FINISHED - HARDWOODS

8. Lumber Production - Sawing
Plain Sawing
Maximum Yield
Varying grain pattern
Common use - Framing lumber
1ST CUT (LOG) AND TRANSPORT TO THE MILL
Plain Sawing
Maximum Yield
Varying grain pattern
CAUSES DRYING DISTORTIONS
DIFFERENT SURFACE APPEARANCE
LESS DURABILITY
Most common use - Framing lumber
WHY???
NOT SEEN
STRUCTURAL QUALITIES ACCEPTABLE
ECONOMICAL

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

10. Typical Sawing Method

11. Lumber Drying Drying Methods Drying Effects Air Kiln Shrinkage
Reduced weight
Increase of strength and stiffness
More dimensional stable
WHY DRY WOOD???
WATER IS 30% TO 300% OF DRY WT.
Seasoned 19% or less
HEAVY, WEAKER, LESS STABLE
Drying Types
Air
CUT & STACKED IN OPEN
AIR DRIED - CAN TAKE MONTHS
Kiln
CUT & STACKED
KILN DRIED - A MATTER OF DAYS
FASTER, HIGHER QUALITY PROCESS
Drying Effects
Shrinkage
LENGTH - NEGLIGIBLE
RADIAL - MEASURABLE AMOUNT
12’ BOARD - 30% TO 15% (2% SHRINKAGE - 1/4”)
TANGENTIAL - UP TO 50% > RADIAL (STRESSES INDUCED)
Reduced weight
Increase of strength and stiffness
More dimensional stable

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

13. Lumber Surfacing Purpose; Designations; S2S, S4S
Smooth
Dimensional precision
Designations; S2S, S4S
Surfacing typically performed before or after drying?
Rough sawn
(not surfaced)
Purpose;
Smooth
Dimensional precision
Designations; S2S, S4S
FRAMING - S4S
SOME HARDWOODS - S2S
Performed primarily after drying
WHY???
“SHRINAGE DURING DRYING
S4S

14. Lumber Defects Growth defects Manufacturing Defects Knots & knot holes
Decay and/or insect damage
Manufacturing Defects
Splits & checks
Crook, bow,
Cup, and/or twist
Growth defects
Knots & knot holes
LIMBS / BRANCHES
Decay and/or insect damage
MOIST CONDITIONS, BORES
Manufacturing Defects
Splits & checks
Crook, bow, cup, and/or twist
WHAT CAUSES THESE DEFECTS???
DIFFERENTIAL SHRINKAGE

15. Lumber Grade & Species Graded by: Lumber sold by - Species and Grade
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
Strength & Stiffness, or
STRUCTURAL OR FRAMING LUMBER
VARIES - SPECIES AND IMPERFECTIONS
Appearance
NON-STRUCTURAL OR FINISH LUMBER
Effect on price
Grade
HIGHER GRADE
HIGHER ALLOWABLE STRESSES
HIGHER PRICE
#1 SELECT - DIFFICULT TO FIND
#2 &3 MOST COMMON FOR FRAMING
BETTER APPEARANCE
EXAMPLE; x 12 (priced in 2001)
# 3 $1 / BF
#2 TWICE (2) THE PRICE OF #3
#1 FIVE (5) TIMES PRICE OF #3

16. Considerations Affecting Strength
Primary Considerations:
Species
Grade
Direction of Load Vs. Grain
Other Factors:
Length & Time of Maximum Loading
Temperature & Moisture Conditions
Size & Shape
Chemical Treatments
Species
HARDWOODS TYP. STRONGER (DENSER)
Grade
LOWER IMPERFECTIONS - INCREASE STRENGTH
Direction of Load Vs. Grain
Length & Time of Maximum Loading
DEFORMATION
WHY DESIGN CONSIDERS DEAD AND LIVE LOAD
Temperature & Moisture Conditions
MOISTURE - DECAY AND STRENGTH REDUCTION
Size & Shape
SLENDERNESS RATIO

17. Lumber Thickness and Width - NOMINAL
< 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.)
Thickness - “Nominal”
< 2 inches - Boards
FRAMING LUMBER - MOST
2 to 4 inches - Dimension Lumber
= to or > 5 inches - Timbers
Widths - “Nominal”
Framing Lumber - 2, 4, 6, 8, 10, 12 inches
WHY NOT Typically WIDER???
Finish /lumber - 1 inch (typ.)

18. 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
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
WHY THE “BREAK AT 6”???
MORE DISTORTION & SHRINKAGE TO ACCOMMODATE DURING SURFACING

19. 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 = board feet (bf)

20. Lumber Pricing Factors
Species
Grade (& drying process)
Lumber Size
FACTORS YOU MUST DECIDE ON
WHY DOES SIZE AFFECT COST / BF???

21. Laminated Wood (Glulam)
Lamination Process
Why Laminate?
Create a size not available naturally
Create Shapes
Improve Quality
Lamination Process
SELECT LUMBER, GRADE
JOINTS - FINGER OR SCARF
ADHESIVES BASED ON EXPECTED MOISTURE
Why Laminate?
Create a size not available naturally
Create Shapes
ARCHES, CURVES, ETC.
Improved Quality
PROCESS CONTROLLED
DEFECTS REMOVED / CONSIDERED
GRAIN DIRECTION CONTROLLED
USES
CHURCHES
LARGE RESIDENTIAL
LODGES, RESTAURANTS

22. Laminated Wood

24. Structural Composite Lumber (PSL)

25. Wood Panel Products Why Panelize? Types More “controlled” product
Efficient use of forest products
Increase labor productivity
Types
Plywood panels
Composite panels
Nonveneered panels
Why Panelize?
More “controlled” product (strength, shrinkage, etc.)
Efficient use of forest products
Increase labor productivity
Types
Plywood
Composite panels
Veneered panels

26. 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”
Thin layers of veneer glued together
VENEERS - ROTARY CUT
Odd number of veneers
Alternating direction of veneers
Face veneers parallel
USES
SAME AS OSB
EXPOSED/PAINTED SURFACES
FORMWORK
COST MORE THAN OSB

27. Composite Panels Parallel outside face veneers
Core - Reconstituted wood fibers

28. Veneer Grades Based on the smoothness & integrity of the veneers
Classifications; A, B, C (plugged), C, D
Price Variances
Based on the smoothness & integrity of the veneers
Classifications; A, B, C (plugged), C, D
B and better sanded smooth
Price Variances (2001)
23/32 Exterior A/C = $31 per panel
23/32 Exterior B/C = $20 per panel
MOST FORMWORK B/C
FINISH AREAS MAY REQUIRE “A”
C Plugged
C Grade
A Grade

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

30. 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
INTRODUCED IN THE EARLY 80’s
GETTING WIDESPREAD USE
Long strand like wood particles
Alternate grain orientation (3-5 layers)
Compressed / glued
Strongest of the Non-veneered
WHY IS IT THE STRONGEST???
ORIENTATION OF STANDS
Generally more economical than Plywood
Uses; Sheathing for floor, roofs, & siding
WHY IS IT GETTING WIDESPREAD USE???
STRUCTURALLY SOUND
ECONOMICAL - SUBBSTITUTE FOR PLYWOOD
NEW GROWTH TREES

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

32. Structural Ratings Specified by Thickness or Span Rating Span Rating
Grade Stamp
For veneered &
nonveneered
Long dimension
perpendicular to
the support
Panel Grade
Span Rating
IN INCHES
PERPENDICULAR TO SUPPORT
LARGER # - ROOF SPAN
SMALLER # - FLOOR SPAN

33. Exposure Durability Classifications
Exterior - siding or continuous exposure
Exposure I; waterproof glue but lower quality veneers
Exposure II; protected environments & minimum wetting
Thickness
Exposure Durability
Exterior - siding or continuous exposure
Exposure I; Waterproof glue - but veneers are not as high of quality as exterior grade (subfloors, sheathing) - most common rating
Exposure II; Minimum wetting

34. Chemical Treatment Combustibility Decay & Insect
FIRE RETARTANT
IMPREGNATED UNDER PRESSURE
Decay & Insect
PRESSURE IMPREGNATED
UP TO 30 YEAR LIFE
TYPES
CREOSOTE
PENTACHOROPHENOL - OILY, CAN’T PAINT
WATERBORNE SALTS - GREENISH - CAN PAINT
Chromated Copper Arsenate (CCA) being phased out
HIGH MOISTURE USES –
WHY NOT USE DECAY RESISTANT WOODS??? (CEDAR, REDWOOD, CYPRESS)
COST & STRENGTH

35. Wood Polymer Composite Planks
Advantages:
Decay Resistance
Easy Workability

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

37. Nails Sharpened metal pins Installation: Hammer or mechanical nail gun
Common Nails
Finish Nails
Other types
Common
flat heads, used mostly for structural connections
Finish Nails
virtually headless, finish woodwork
Common - Used for Framing, Large Shank & Head
Box - Smaller Shank, less chance for splitting wood, Used Shingles, Rough Casings
Casing, Finish, Brad - Finish Components, Sink Head
Deformed Shank - Very Hard to Remove, DW & Flr.
Concrete - Masonry & Concrete
Cut - Finish Flooring - SQ Head Reduces Cracking
Roofing - One of Many, Some Have lead/Rubber Washers

38. Nails Size - Measured in pennies Coatings Bright/ Plain uncoated steel
Corrosion-resistant
Resin/Vinyl
Size - Measured in “pennies” (Price of 100 nails long ago)
Corresponding Lengths Same for Common & Finish
Most Common Light Frame Nails - 16d for 2”, 10D AND 8D
Coatings
Bright/ Plain uncoated steel
MOST COMMON USED - NON CORROSIVE OR CONCEALED CONDITION
Corrosion-resistant
“EXPOSED TO WEATHER
RUST OR STAIN LUMBER
GALVANIZED, ALUM., SS
Resin/Vinyl
Decrease Drive & Increase Holding
This nail has a smaller shaft – commonly called a ‘sinker’

39. Anchorage Face, End, or Toe Which Has the Most Holding Power???
Face - Perpendicular to Grain
End - Parallel
Toe - Angle to Grain
Which Has the Most Holding Power???
Which is most common???

40. 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
APPLICATIONS
FRAMING
SHEATHING
ROOFING
Battery Powered Electric Nailer
Collated Nails

41. Wood Screws Head type Sizing - Installation Holding power Uses
Types of ‘Heads’
Head type
Sizing -
Gauge & Length
Installation
Holding power
Uses
“Head” type
PHILLIPS
SLOTTED
SQUARE HEAD
PAN, FLAT, ROUND, ETC.
Sizing - Gauge & Length
WIRE GAUGE (SAMPLES #8 & #10)
LENGTH IN INCHES (AND FACTIONS)
Installation
HAND SCREW DRIVER
“SCREW GUN”, OR DRILL
HOLDING POWER
TIGHTER, STRONGER THAN NAILS
CAN BE “BACKED” OUT, & REINSERTED
Uses
CABINETWORK
SOME FRAMING APPLICATIONS
DECKING - BETTER HOLD - LESS SQUECK
Deck Screws

42. Lag & Drywall Screws Lag Screws Drywall screws Large screws
Square or octagonal head
Installed w/ wrench
Drywall screws
Used to attach drywall
Lag Screws
Large screws
Very LARGE Screws, Wrench, ¼ 2-6 in., ½ to 10”
FOR HEAVIER STRUCTURAL CONNECTIONS
Square or octagonal head
Installed w/ wrench
Drywall screws
Used to attach drywall
Drywall Screws (Size, 1 ¼, 1 5/8, 2 “,
Screw Gun - Fast, Wood or Metal,

43. Bolts Heavier structural connections Sizes Types Washers Machine
Carriage
Washers
Heavier structural connections
COMMONLY USED W/ TIMBER CONSTRUCTION
Sizes
1/4 inch to 1 inch+
LENGTH; ABOUT ANY (PRACTICALLY 10-12”)
Types
Machine
SQUARE OR OCTAGONAL HEAD
USED WITH WASHER
Carriage
ROUND BUTTON HEAD
SQUARE SHANK INHIBITS TURNING
Washers
DISTRIBUTE THE COMPRESSIVE FORCE

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

45. Sheet Metal Framing Devices
Light Wood Framing
Joist Hangers
Framing anchors
Angle anchors
Rafter anchor
Heavy Timber or Laminated Framing
NUMEROUS TYPES AND SHAPES
MOST COMMON - JOIST HANGER
LIGHT WOOD FRAMING - ATTACHED WITH SCREWS OR NAILS
HEAVY TIMBER - ATTACHED WITH BOLTS / LAGS

46. Adhesives Widely used in the manufacture of wood products On Site Uses
Wood panels
Laminated wood
Cabinetry
On Site Uses
Sheathing
ON SITE
LESS USES BECAUSE OF NEED TO CLAMP
USES
FLOOR SHEATHING
BASE (SOLE) PLATES
WALL PANELS
PANELING (WHERE THERE IS A NEED FOR CONCEALED FASTENERS)
INCREASE STIFFNESS, ELIMINATE “SQUEAK”

47. Wood Manufactured Components
Trusses
Wood I-Joists
Beams
Panel Components

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

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

50. I-Beams Uses Sizes Composition Cost FLOORS & ROOFS
Typically, 9-1/2” TO 24 “ DEEP
LENGTH UP TO 40 FEET+
Composition & cost
TOP & BOTTOM - LUMBER OR Laminated
WEB - OSB, PLYWOOD
COST - COMPARABLE TO 2x

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