Lecture 10 - Wood - Design
Type Lecture
Date @November 16, 2023
https://www.youtube.com/watch?
Materials v=iDUbATJpVZM&ab_channel=ShannonHilchie
Reviewed
What’s up with Wood
Wood Factors
Wood Compression
Wood Bending
Wood Shear
Wood Design Tables are our friend
Hardwood/Softwood
Hardwoods = Deciduous trees (mostly)
Broad leafed trees that shed their leave at the end of each growing season.
Softwoods = Coniferous trees (mostly)
Cone bearing trees with needle-like leaves. Most coniferous trees keep their
leave through the winter giving them the name evergreens.
In Canada most lumber and wood products come from the more plentiful softwoods,
but Poplar and Aspen are increasingly used for LVL and PSL
Species of Structural Wood
Out of 30 common Softwoods in Canada, four tend to be used for construction:
Lecture 10 - Wood - Design 1
, Spruce – Dimensional lumber (2x4 to 2x12) used for residential and light framing.
Cheapest.
Pine – Common for trim work
Cedar – Decks and exterior applications
Douglas Fir – Used in heavy construction (Gludaslam)
Wood Properties Cross Section of a Cell Structure
Tree
SPF Nominal (2x4, 2x6, 2x8)
2x10, 2x12) Lumber is the
NORM (QUIZ QUESTION)
Wood…
Has moisture
Shrinks
Is Non-Isotropic
Imperfect
Creeps
Rots (and gets eaten)
Burns
Lecture 10 - Wood - Design 2
, Factors that impact Wood Strength
Species
Grade Category/Grade
Size
System Effects
Load Duration
Service Condition (Wet/Dry)
Chemicals (Preservative/Fire Retardant)
Lateral Stability (Buckling)
Lumber Grades
Strength and Modulus of Elasticity
Lecture 10 - Wood - Design 3
Type Lecture
Date @November 16, 2023
https://www.youtube.com/watch?
Materials v=iDUbATJpVZM&ab_channel=ShannonHilchie
Reviewed
What’s up with Wood
Wood Factors
Wood Compression
Wood Bending
Wood Shear
Wood Design Tables are our friend
Hardwood/Softwood
Hardwoods = Deciduous trees (mostly)
Broad leafed trees that shed their leave at the end of each growing season.
Softwoods = Coniferous trees (mostly)
Cone bearing trees with needle-like leaves. Most coniferous trees keep their
leave through the winter giving them the name evergreens.
In Canada most lumber and wood products come from the more plentiful softwoods,
but Poplar and Aspen are increasingly used for LVL and PSL
Species of Structural Wood
Out of 30 common Softwoods in Canada, four tend to be used for construction:
Lecture 10 - Wood - Design 1
, Spruce – Dimensional lumber (2x4 to 2x12) used for residential and light framing.
Cheapest.
Pine – Common for trim work
Cedar – Decks and exterior applications
Douglas Fir – Used in heavy construction (Gludaslam)
Wood Properties Cross Section of a Cell Structure
Tree
SPF Nominal (2x4, 2x6, 2x8)
2x10, 2x12) Lumber is the
NORM (QUIZ QUESTION)
Wood…
Has moisture
Shrinks
Is Non-Isotropic
Imperfect
Creeps
Rots (and gets eaten)
Burns
Lecture 10 - Wood - Design 2
, Factors that impact Wood Strength
Species
Grade Category/Grade
Size
System Effects
Load Duration
Service Condition (Wet/Dry)
Chemicals (Preservative/Fire Retardant)
Lateral Stability (Buckling)
Lumber Grades
Strength and Modulus of Elasticity
Lecture 10 - Wood - Design 3