Structural Lumber Defects Flashcards Preview

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Flashcards in Structural Lumber Defects Deck (12)
1

lumber has defects bc

natural material

2

defects are present in lumber, and occur during

manufacture

3

most common.
classified by quality, size, occurrence.
over 10 types.

knots

4

separation of wood fibers,
across or through growth rings,
result of improper seasoning.

check

5

open area between growth rings,
contains resin.

pitch pocket

6

lengthwise separation,
between or through growth rings.

shake

7

sim. check,
except extends completely through.
typ. @ ends.

split

8

bark/absence of wood,
on edge or corner of lumber,
from any cause,

wane

9

common manufacturing defect.
caused by uneven drying

warping

10

warping:
parallel to length of lumber,
inline w lumbers flat side.

bow

11

warping:
parallel to length of lumber,
perpendicular to flat side.

crook

12

warping:
across width,
deviation from true plane.

cup