What are the defect in timber?

What are the defect in timber?

There are various types of defects in timber as a construction material….

• Dry Rot in Timber. Ad.
• Wet Rot in Timber.
• Brown Rot in Timber.
• White Rot in Timber.
• Blue Stain in Timber.
• Heart Rot in Timber.
• Sap Stain in Timber.

What are the types of wood warping defects?

The types of wood warping include:

• bow: a warp along the length of the face of the wood.
• crook: a warp along the length of the edge of the wood.
• kink: a localized crook, often due to a knot.
• cup: a warp across the width of the face, in which the edges are higher or lower than the center of the wood.

What are imperfections in wood called?

A defect is simply an abnormality or irregularity found in wood.

What are artificial defects in timber?

Artificial defects: Caused by careless handling, incorrect conversion and seasoning techniques and inadequate protection of timber.

How can timber defects be prevented?

The dry rot may be prevented by using well-seasoned timber free from sap. When part of the timber is seriously affected by dry rot, the damaged portion may be completely Removed and the remaining unaffected portion should be painted with a solution of copper sulphate.

What is Bow defect?

A bow is a defect in a board that bends along the grain lines. If the board were laid across a flat surface, both ends would be in the air. There is no warp across the grain. This can be caused by uneven air circulation as the wood dries. Any bowing causes internal stresses that will make the board difficult to cut.

What is the most common lumber defect?

Knots
Knots are probably the most common of the natural defects in lumber. Most branches of forest-grown trees originate at the center of the trunk and grow in diameter and length so long as conditions are favorable. The branch end or knot in the trunk is therefore typically shaped like a cone with its apex at the pith.

What is Burl timber?

Burls form on tree roots, trunks and branches as a result of the abnormal development of bud growth cells. They appear as wartlike lumpy growths, roundish in shape and covered in coarse bark. Burls contain twisted, compact wood that is tougher than the wood from the rest of the tree.

What is the type of defect?

Following are the common types of defects that occur during development: Arithmetic Defects. Logical Defects. Syntax Defects.

What is a wood defect?

Wood defects are usually an abnormality or irregularity in the wood that arise from many different causes. For example, natural and acquired wood defects can be caused from insect and fungal attack, or rapid tree growth. There are also natural wood defects that we cannot control.

What do you mean by defects in timber?

Defects in timber may be defined as, any undesirable character -natural or artificial- that lowers its strength, durability or quality.

What are the different types of wood defects?

Wood Defects. 1 Bow (Bowing) The curvature of a piece of sawn timber in the direction of its length, cf. Spring and Curvature. 2 Boxed Heart. 3 Checks. 4 Compression Fanures. 5 Cup (Cupping)

What causes a bow on a wood board?

Most of the following are caused by problems with cutting, stacking, or drying the wood—with the exception of naturally-occurring knots. Bow: A bow is a curve on the face of a board, typically extending from one end to the other.

What causes defects in the seasoning of wood?

Faulty method of seasoning causes serious defects in woods. During seasoning of timber, exterior or surface layer of the timber dries before the interior surface. So, stress is developed due to the difference in shrinkage. In a perfect seasoning process, stress is kept minimum by controlling the shrinkage.