Division 6 correct answers Wood, Plastics, and Composites
What is the structure of a tree? correct answers Bark is the outermost protective layer, Cambian
layer is the source of new cells, Sapwood is the layer of living cells that store and transport
nutrients, Heartwood makes up the most mass and is dead cells that contribute to structural
strength, Pith is the innermost first years' growth
Softwood comes from what type of trees? correct answers Coniferous trees (cone bearing)
Softwoods have a what cell structure? correct answers simple
From what regions do softwoods come from? correct answers Primarily North America
T/F All softwoods are harder than hardwoods correct answers False
Hardwoods come from what type of trees? correct answers Deciduous (Broad leaf trees)
T/F hardwoods have a more complex cell structure correct answers T
Environmentally Certified Wood correct answers Wood from a managed forest and has a chain
of custody certification that makes it eligible for LEED points
Plain Sawn Lumber correct answers Cut in a way that the growth rings are parallel to wider face
of the board
Quartersawn lumber correct answers Growth rings at an angle and make for a more interesting
grain pattern but generates more waste
Seasoning correct answers The drying of wood through leaving it in the air or putting it in the
kiln
Standard lumber is seasoned to what percentage? correct answers 19%
Decay causing fungi can't live in wood with a moisture content less than... correct answers 20%
longitudinal shrinkage correct answers in wood, shrinkage along the length of the log
radial shrinkage correct answers in wood, shrinkage perpendicular to the growth rings
tangential shrinkage correct answers In wood, shrinkage along the circumference of the log.
Surfacing correct answers Makes wood smooth and more dimensionally precise
S4S correct answers surfaced on four sides
, Structural Grading of Lumber correct answers Lumber is graded and stamped for structural
strength and stiffness
What are the structural properties of wood? correct answers Wood has good compressive and
tensile strength, strength varies with direction of grain
Nominal Dimensions and Actual Dimensions correct answers Standard lumber dimensions such
as 2x4 but in reality it is 1 1/2 x 3 1/2 inches. These are the actual dimensions
Wood is quoted by... correct answers Dollars per thousand board feet in the U.S. and cubic
meters everywhere else.
Gluelaminated Wood (Glulam) correct answers Joining of many smaller strips of wood with glue
to form glue-laminated wood. Provides great size shape and quality
Structural Composite Lumber correct answers aka engineered lumber is made up of wood veneer
or fiber strands and glue
Laminated Strand Lumber (LSL) correct answers made with long strands of wood up to 12
inches in length. Strands are bonded with a resin in a steam pressing process. typically sued for
short strand beams and columns.
Oriented Strand Lumber (OSL) correct answers Structural composite lumber made from
shredded wood strands, coated with adhesive, and pressed into a rectangular cross section
Laminated Veneer Lumber correct answers Made from thin wood sheets as wide as the member
is deep and are glued and laminated into thicker sheets
Parallel Strand Lumber (PSL) correct answers Made from long thin strips of wood veneer glued
and press in a similar process to OSL and LSL but with the strips parallel and uniform. This is
the heaviest strongest and most expensive structural composite lumber
wood-plastic composite (WPC) correct answers Made from wood fibers and plastic of various
types mixed with other ingredients which are then heated and pressed or injection molded into
final form
Span Rating correct answers Lab load testing with results stamped onto the back of the panel to
permit the use of many panels while achieving a structural objective
Veneer grades correct answers A, smooth paintable and no more than 18 neat repairs, B, solid
surface with repairs and tight knots, C plugged, improved C veneer splits less than or equal to
1/8" wide and knot holes 1/2" * 1/4" knot holes plugged, C, tight knots less than or equal to 1-
1/2", knot holes to 1" across grain, D, Knots and knot holes to 2-1/2" width across grain