Wood Defects

Question 1

• natural wood defect


- these are in effect the basal stamps of incipient or cast-off branches in the living tree

Answer 1

Knots

Question 2

• natural wood defect; type of knot


- small knots 1/2 “ (12.5mm) or under often caused by the shedding of early branches

Answer 2

Pin knots

Question 3

• natural wood defect

• knots sliced through their length during sawing

• “slash knots”

Answer 3

Spike or Splay knots

Question 4

• natural wood defect; type of knot


- dead knots which are still sound and difficult to dislodge

Answer 4

Encased knots

Question 5

• natural wood defect; type of knot


- two or three knots springing from a common center

Answer 5

Branched knots

Question 6

• natural wood defect

• built-in tensions are created which tend to level out either in the growing tree under certain adverse conditions resulting to extensive splitting in the weakest links

Answer 6

Shakes / “splits”

Question 7

• natural wood defect; type of shake


- log splits from the pith or heart radially along the medullary rays


- one shake is a “heart shake” while two is a “double heart shake”, several is a “star shake”

Answer 7

Radial shakes

Question 8

• natural wood defect; type of shake


- project inwardly; from outside


- result of severe weather

Answer 8

Frost shakes

Question 9

• natural wood defect; type of shake


- “ring shake”; shakes are with the rings of the tree

Answer 9

Tangential shakes

Question 10

• natural wood defect; type of shake


- when log is opened, there are spots in the middle body of the trunk

Answer 10

Cross shakes

Question 11

• natural wood defect


- “resin pockets”; can appear either as thin veins or shallow cavities filled with resin


• usually caused by damage to the cambium layer in resinous wood

Answer 11

Pitch Pockets/ Pitch Veins

Question 12

• natural wood defect


- damage to the cambium layer by small insects; may show as small dots or patches of brown cork deeply buried in some woods

Answer 12

Pitch Flecks

Question 13

• natural wood defect


- patches of ingrowing bark caused by exterior damage to a growing tree


- ex: nailing into a tree

Answer 13

Rind Galls

Question 14

• natural wood defect


- the wood usually separates and breaks away along the ring during conversion

Answer 14

Internal Sapwood

Question 15

• natural wood defect


- can be used either by fungal or insect attack, irritating the cambium layers, resulting in large lipid growths forming a dense mass

• may enhance the value of timber

Answer 15

Burls / Burrs

Question 16

• natural wood defect


- tissue formed over a wound in a tree resulting in unnatural growth

Answer 16

Callus

Question 17

• natural wood defect


- caused by fungoid disease; dead sections of bark

Answer 17

Canker

Question 18

• natural wood defect


- partially heated fire scar; depression on the surface of the log where the tree failed to recover from the injury

Answer 18

Catface

Question 19

if the structure of wood is unequal or lacking in elasticity, and incorrect seasoning various forms of distortion, splitting, will occur.

Answer 19

Artificial defect

Question 20

• artificial wood defect

• hollows across the width, forming a rounding on the under face

• often due to incorrect piling

Answer 20

Cupping or Rounding

Question 21

• artificial wood defect


- plank is curved like a bow throughout its length

Answer 21

Bow or Bowing

Question 22

• artificial wood defects


- edge bend; wood remains flat but bends edgewise

Answer 22

Sprining / “crook”

Question 23

• artificial wood defect


- diagonals are curved; “in-winding”

Answer 23

Twisting

Question 24

• artificial wood defect


- terms for distortion in one or more directions

Answer 24

Warping or Casting

Question 25

• artificial wood defect


- butt ends of the plank splits open, caused by too rapid drying


- happens after cutting the wood

Answer 25

End Splitting

Question 26

• artificial wood defect


- wood surface is covered with small splits along the grain caused by too rapid drying in hot sun

Answer 26

Sun Checking

Question 27

• artificial wood defect


- the result that the dry outer layers are in tension, and the moist interior compression

Answer 27

Case Hardening

Question 28

• artificial wood defect


- surface of the wood lifts in small layers caused by the cutting action, structural weakness, or incorrect seasoning

Answer 28

Flaking

Question 29

• artificial wood defect

- grain runs obliquely to the longitudinal axis due to incorrect sawing

Answer 29

Diagonal grain

Question 30

• artificial wood defect

• resulting in severe internal stresses and subsequent checking or disruption of the wood fibers, not visible from outside

Answer 30

Honeycombing

Question 31

• artificial wood defect


- characterized by extensive shrinking and warping

Answer 31

Collapse

Question 32

thin layer entirely surrounding the trunk that is in active growth

Answer 32

Cambium layer