Power point WOOD

Question 1

What is a medullar ray?

Answer 1

horizontal growth
cells that create flecking
pattern in wood that is
desirable to wood workers.

Question 2

What part of the tree is considered to be the structural
core of the tree and comprised of
mostly dead cells?

Answer 2

Heart wood

Question 3

What part of tree is considered to be the part of the
tree that is still growing and also is the part
of the tree that transports
nutrients through the tree?

Answer 3

Sapwood

Question 4

What is the difference between heart wood vs. Sapwood?

Answer 4

Heartwood acts as the structure of the
tree and is more resilient to decay due to
the accumulation of resin.
•Sapwood acts as the vascular system of
the tree, but is far more susceptible to
decay.

Question 5

This type of wood is also called
sapling growth. It is the section of the tree that is
common today as a primary
material for dimensional
lumber due to its fast growth.

Answer 5

Juvenile wood

Question 6

This type of tree:
Sheds its leaves 
•is Not necessarily hard but generally harder 
• is More difficult to work 
• is More expensive 
•has greater wear resistance 
•Uses: furniture, stairs, flooring, cabinetry,
moldings, paneling

Answer 6

Hard wood: Deciduous trees (trees with leaves)

Question 7

Maple, cherry, oak, walnut, ash,

hickory, bass, and beech are all examples of what type of tree?

Answer 7

Hard wood trees

Question 8

This type of tree:
•Has needles and is sometimes known as an
evergreen trees
•Easier to work •Less expensive and usually grows faster than
hardwood trees
•Uses: Framing lumber, trim, siding •Typical structural framing lumber is SPF or
spruce pine fir (due to speed and vertical
nature of their growth).

Answer 8

Soft wood: Conifers (Cone bearing)

Question 9

Southern yellow pine, Douglas fir,

Spruce, Pine. and Larch are examples of what type of tree?

Answer 9

Soft wood conifer trees

Question 10

What type of wood is generally used for the building industry?

Answer 10

Juvenile wood

Question 11

If you were building a piece of furniture, what would be a better lumber selection; red
maple or spruce?

Answer 11

Red maple. Hard woods are typically used for furniture, stairs, flooring, cabinetry,
moldings, paneling.

Question 12

Most dimensional lumber and
heavy timbers are cut with this sawing
method.

Answer 12

Plain sawn

Question 13

This sawing method is generally used for hardwoods and edge-grained or Vertical
Grained (softwoods).
•Ring angle is 45º-90º to board
face

Answer 13

Quarter sawn

Question 14

This sawing method is generally used for hardwoods and edge-grained or Vertical
Grained (softwoods).
Ring angle is 30º-60º to the
face of the board

Answer 14

Rift sawn

Question 15

Decay causing fungi cannot survive

in wood with a moisture content below what?

Answer 15

(MC) below ~20%.

Question 16

After lumber is sawn, it is seasoned

(dried), either in ____ or in _____

Answer 16

After lumber is sawn, it is seasoned

(dried), either in air or in kilns.

Question 17

What is air drying wood?

Answer 17

Lumber is stacked outdoors with the
individual pieces stickered so that the
sun and the wind can dry the lumber
naturally.

Question 18

What is kiln drying wood?

Answer 18

Lumber is placed in a large oven where
the temperature, humidity and air
circulation are controlled.

Question 19

What type of wood drying eliminates fungus and

insects?

Answer 19

Kiln drying

Question 20

This occurs as lumber
is cut and the wood below the
bark is exposed to the air. It is also most prevalent
along the growth rings.

Answer 20

shrinkage

Question 21

Absorbing water increases
the size of the wood and can
cause serious damage to
wooden surfaces. This movement often occurs
with changes in weather and
temperature. What is this referring to?

Answer 21

This lumber movement refers to swelling

Question 22

Due to the cut of the board
the internal forces of the grain
pull at the ends due to the cut,
drying methods, or both. This refers to what type of distortion?

Answer 22

Bow distortion

Question 23

this occurs more
often in thicker boards as the
out and inner sections of the
boards do not dry at equal rates. What distortion type is this?

Answer 23

Checking

Question 24

This type of distortion occurs across the face
of the board as the rings attempt
to flatten. You may also see
diamonding. What is it?

Answer 24

Cupping

Question 25

Like bowing, the internal
forces of the wood grain are
pulling at different rates either
due to cutting, drying or both. This type distortion is what?

Answer 25

Twist

Question 26

This type of distortion often occurs
along the juvenile edge of tree
causing uneven drying and
tension. What type is this?

Answer 26

Crook

Question 27

What is timber?

Answer 27

Timber is a piece of wood, with or
without bark, that is ready to be made
into something else like lumber

Question 28

Wood that has been cut to

size. Dimensional ______ (2” x 4”, 2” x 6”,
etc. ) What type of wood is this?

Answer 28

LUMBER:
•Lumber is wood that has been cut to
size.
•Dimensional lumber (2” x 4”, 2” x 6”,
etc.)

Question 29

Normally defined as lumber that is less
than 2” nominal thickness and 6” or more wide
(typically 1 x 6, 1 x 8 …(3/4”) thick). What is this?

Answer 29

Board

Question 30

What it Fiber Stress in Bending (Fb)?

What is Modulus of elasticity?

Answer 30

Fiber Stress in Bending (Fb): Amount lumber
can be loaded before failure.
• Modulus of Elasticity (E): Amount something
deflect and elastically return.

Question 31

______ starts in warm locations where
moisture is able to penetrate into wood
members.

Answer 31

Decay

Question 32

What four things does Fungi need to grow?

Answer 32

Fungi need four things for survival and grow
•Oxygen
• Mild to warm temperature
• Water/moisture
•Food

Question 33

What three conditions attract termites?

Answer 33

• Warm damp spaces (crawlspaces
are ideal places to establish a nest)
•Rotting wood
•Cracks or holes in foundations

Question 34

What are three methods of chemically treating lumber?

Answer 34

• Surface treat (brush, roll, spray)
• Dip treat (limited penetration)
• Pressure treat

Question 35

CCA: Copper Chromium Arsenate (not used for residential since 2003 due
to environmental and safety issues),
ACQ: Alkaline Copper Quest, CA: Copper Azole, ACQ and CA are used for residential, and SBX: Sodium Borates – limited to indoor
applications (sill plates and interior
framing) – SBX is water soluble are all examples of what?

Answer 35

Pressure treatment chemicals

Question 36

Cabinet grade plywood, not
used for construction unless
it is a finished surface.

Answer 36

Hardwood Plywood

Question 37

What is Rotary Cut, Quarter Slice, and Plane slicing

Answer 37

ROTARY CUT
The log is centered and
a knife cuts the log to
“unroll” the wood.

QUARTER SLICE
By cutting the tree in
quarters the veneer can
be cut perpendicular to
the growth rings.

Plane Slicing
The log is cut length wise
disregarding grain.

Question 38

This type is More popular and cheaper
than plywood, has a higher sheer strength than
plywood, and is prone to swelling with
prolonged exposure to
moisture. What is this?

Answer 38

Oriented Strand Board: OSB

Question 39

HDF and MDF are highly
susceptible to moisture
and are not used in either
structural or exterior
conditions. True or false?

Answer 39

True

Question 40

What is plywood?

Answer 40

•Several layers (veneers) of solid

wood (~1/8”) glued together