Timber defects refers to imperfections that occur in timber boards. Defects can occur through a number of reasons.
- – splits
- – checks
- – warping
- – shakes
- – bowing
- – knots
- – twists and winds
During the drying process of timber, if the wood is not dried in the correct manner, stresses in the wood can occur, making it difficult to work it or impossible to use for a certain project. Before you use any solid woods for a project always inspect the surface for obvious faults such as:
- Uneven Grain
Checkout the end grain section to see how the piece was cut from the log, and to check for any distortion.
Sight along the length to test for twisting or bowing. Also look for any evidence of insect attack.
The Most Common Defects Are:
1) Surface Checking
Surface checking is usually found along the rays of the wood. It is caused by too rapid drying of the surface of the timber.
2) End Splits
Such splits are very common defects caused by exposed ends drying out to rapidly. Sealing the ends of the stacked boards with waterproof paint can prevent this.
3) Honeycomb Checks
This defect is caused when the outside of the timber stabilizes before the inside is dry. The inside shrinks more than the outside, resulting in torn internal fibres.
These are defects in the structure of the wood which are caused by growth defects or shrinkage stresses. Cup or ring shakes are splits that occur between the annual growth rings.
5) Bowing Or Warping
This is caused by badly stacked boards, wild grain or stresses caused by poor seasoning of the timber. Reaction wood is also prone to twist or cast when its cut or dried.
6) Dead Or Encased Knots
These are the remains of dead branch stumps overgrown by new annual growth rings. Generally the wood around the knot has an irregular grain pattern and is very difficult to work.
7) Ingrown Bark
This can mar the woods appearance and weaken its structure.