3.7 : 木材の欠陥

Growth defects in wood include knots, which are formed where branches connect to the tree trunk, knotholes that result from loose knots falling out, decay and insect damage.

Shakes are minor fractures running along or across the annual rings and are common wood defects.

Wane refers to the lack of wood or the presence of bark along a board's edge.

Checks are the radial cracks that develop in logs and are manufacturing flaws that occur due to circumferential shrinkage leading to contraction during the seasoning process.

Warp refers to any deviation from a flat, accurate surface in the board. Warp types include crooking, bowing, twisting, and cupping in the lumber.

Honeycombing refers to internal cracks in a board that occur due to improper seasoning.

Torn grain results from wood being chipped or scooped out from the board's surface due to cutting or planing. These defects impact the strength of the wood.

Surface stains might appear on wood after it has been processed into lumber. These brown, green, or blue stains usually affect the appearance but not the strength of the lumber.