Power point WOOD Flashcards
What is a medullar ray?
horizontal growth
cells that create flecking
pattern in wood that is
desirable to wood workers.
What part of the tree is considered to be the structural
core of the tree and comprised of
mostly dead cells?
Heart wood
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?
Sapwood
What is the difference between heart wood vs. Sapwood?
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.
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.
Juvenile wood
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
Hard wood: Deciduous trees (trees with leaves)
Maple, cherry, oak, walnut, ash,
hickory, bass, and beech are all examples of what type of tree?
Hard wood trees
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).
Soft wood: Conifers (Cone bearing)
Southern yellow pine, Douglas fir,
Spruce, Pine. and Larch are examples of what type of tree?
Soft wood conifer trees
What type of wood is generally used for the building industry?
Juvenile wood
If you were building a piece of furniture, what would be a better lumber selection; red
maple or spruce?
Red maple. Hard woods are typically used for furniture, stairs, flooring, cabinetry,
moldings, paneling.
Most dimensional lumber and
heavy timbers are cut with this sawing
method.
Plain sawn
This sawing method is generally used for hardwoods and edge-grained or Vertical
Grained (softwoods).
•Ring angle is 45º-90º to board
face
Quarter sawn
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
Rift sawn
Decay causing fungi cannot survive
in wood with a moisture content below what?
(MC) below ~20%.
After lumber is sawn, it is seasoned
(dried), either in ____ or in _____
After lumber is sawn, it is seasoned
(dried), either in air or in kilns.
What is air drying wood?
Lumber is stacked outdoors with the
individual pieces stickered so that the
sun and the wind can dry the lumber
naturally.
What is kiln drying wood?
Lumber is placed in a large oven where
the temperature, humidity and air
circulation are controlled.
What type of wood drying eliminates fungus and
insects?
Kiln drying
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.
shrinkage
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?
This lumber movement refers to swelling
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?
Bow distortion
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?
Checking
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?
Cupping
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?
Twist
This type of distortion often occurs
along the juvenile edge of tree
causing uneven drying and
tension. What type is this?
Crook
What is timber?
Timber is a piece of wood, with or
without bark, that is ready to be made
into something else like lumber
Wood that has been cut to
size. Dimensional ______ (2” x 4”, 2” x 6”,
etc. ) What type of wood is this?
LUMBER: •Lumber is wood that has been cut to size. •Dimensional lumber (2” x 4”, 2” x 6”, etc.)
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?
Board
What it Fiber Stress in Bending (Fb)?
What is Modulus of elasticity?
Fiber Stress in Bending (Fb): Amount lumber
can be loaded before failure.
• Modulus of Elasticity (E): Amount something
deflect and elastically return.
______ starts in warm locations where
moisture is able to penetrate into wood
members.
Decay
What four things does Fungi need to grow?
Fungi need four things for survival and grow •Oxygen • Mild to warm temperature • Water/moisture •Food
What three conditions attract termites?
• Warm damp spaces (crawlspaces
are ideal places to establish a nest)
•Rotting wood
•Cracks or holes in foundations
What are three methods of chemically treating lumber?
- Surface treat (brush, roll, spray)
- Dip treat (limited penetration)
- Pressure treat
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?
Pressure treatment chemicals
Cabinet grade plywood, not
used for construction unless
it is a finished surface.
Hardwood Plywood
What is Rotary Cut, Quarter Slice, and Plane slicing
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.
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?
Oriented Strand Board: OSB
HDF and MDF are highly susceptible to moisture and are not used in either structural or exterior conditions. True or false?
True
What is plywood?
•Several layers (veneers) of solid
wood (~1/8”) glued together
