Slide 2 Flashcards
What does seasoning green wood do?
Reduces moisture content
What are the three methods of seasoning?
Air drying, forced air drying, kiln drying
Benefits of kiln drying includes the control kilns have over:
Temperature, humidity, air pressure, air circulation
What does controlled seasoning minimize?
Loss of wood value by reducing effects of drying
What is not the same as natural defects?
Lumber defects
What is a check?
A separation of wood fibres along the rays perpendicular to growth rings
What causes checks?
The surfaces of wood dries faster than its interior
What is a shake?
A separation of wood fibres along the growth rings
When do shakes occur?
During the growth of the tree
What is a split?
A complete separation of wood fibres at the end of a member
What causes splits?
A weakness that occurred during growth and was aggravated during drying
What is a wane?
An absence of wood or presence of bark at the corner or edge
What do wanes, knots, checks, splits, and shakes do?
Reduce the strength of wood
What produces a knot?
Branches
What are included in seasoning defects?
Crook, bow, cup, twist
What can happen when the moisture content is further reduced?
Splits
What are 4 pros of using wood?
Easily cut and worked, easily fastened, good insulating properties, doesn’t readily transmit sound
What are 4 cons of using wood?
Shrinks and swells in response to moisture, prone to warping, susceptible to decay, combustible
What type of material is wood?
Organic
What are three degradations that wood is subject to?
Fungal decay, insects, weathering
What are the 3 basic types of loading?
Compression, tension, shear
Wood is stronger:
Parallel to the grain
A load on a beam or a joist creates:
Compression and tension
When opposite forces push on a wood member (narrow plane), it is called a:
Shear
