chapter 7 Flashcards
wood construction
types of wood used in construction are softwoods including ?
pine , fir and spruce
some ‘’’ are related to the natural growth of trees and include:
wood is never dimensional true
weather effects size and shape
wood does to shrink or swell uniformly
intrinsic defects include knots, knotholes, decay insect damage, splits and warping
wood strength varies significantly with species, grade, age and growth rate of tree
wood strength changes overtime after components are placed un use
disadvantage to wood
solid lumber includes:
DL
B
T
dimensional lumber , boards and timbers
lumber with standard measurements for use in building construction
dimensional lumber
actual dimensions of processed lumber do not match the
nominal dimensions of lumber
dimensional lumber is available in lengths of
8-24 ft p. 182
standard tensile strength of wood is :’’’ PSI
700 psi
most structural lumber has level of moisture of
19 % or less
moisture is expressed in terms of
specific gravity
mass of a substance compared to the weight of an equal volume of water at a given temp
specific gravity
direction of growth of a tree
grain
wood is stronger ‘’ to the grain than ‘’ the grain
parellel / against
other factors that will contribute to the component strength include:
M
S
S
OF FASTERNERS AND APPLIED POSITION IN RESPECT TO THE ‘’ OF THE WOOD
material , shape and size of fasterners and applied position in respect to the grain of wood
BONDING pieces of wood with glue or resin to form finished shapes is ‘’ wood ? Components are rated according to the amount of weight they can carry once complete advantages of strength and cost efficiency disadvantages would be failure and fire conditions went unprotected.
engineered wood
what wood provides the advantages of strength and cost efficiency
engineered wood p.183
lightweight construction is a term coined in the 1950s to ref to
milled ( lightwood ) lumber in contrast to heavy timber
material made of wood strips and resin, shaped and BONDED with HEATand or pressure is what wood ?
laminated wood
wood members made by joining small, flat strips of wood together with GLUE IS WHAT ‘’ BEAM
glue laminated beam
a simple but weak joint.. connected b/tw 2 parts made by simply securing ENDS surfaces together w/o additional shaping at the ends
butt joint
current research indicates that the heat of a fire has essentially what effect on the adhesive that are used in contemporary glum beam
no effect
connection b’tw 2 cuts made by the cutting of overlapping mating parts and securing them by glue or fasteners so that the joint is not enlarged
scarf joint
connection b’tw 2 parts made by cutting complementary mating parts, and the securing the joint with glue
finger joint p.185
what uses sheets of veneer peeled from the outer portions of the log , beams feature a smooth face suitable for finish work
laminated veneer lumber ( lvl)
what is made from veneer that are not as uniform as those used in LVL ? These veneers produce odd shaped strands that are coated with an adhesive and cured under pressure. Commonly produced in standard size ranges from 2 to 8 feet., strongest of the three structural composite lumber that can be used for heavy load column in long spans
Parallel strand lumber ( PSL) p. 186