DEFECTS OF TIMBER

DEFECTS OF TIMBER:

                                           Any disturbance in the quality that affects the strength, workability, durability, utility, appearance and decay etc is said to be the defects in timber.

Growth Related Defects:

1. Shakes:

  Change in shape of trunk or cracks in timber are called shakes. It is of three types.

·         Star shakes.

·         Hearth shakes.

·         Cap.

2. Knots:

                  A knot is the base of branch that is attached with the wood of tree trunk or to a large branch.

3. Rind galls:

                    Swelling due to injuries inflected to the wood in its younger age.

4.     Twisted fibers:

                      Wood is twisted due to strong winds during the early stages of its growth.

5.     Upsets:

                  Change in wood direction in young age by to fast blowing winds.

DEFECTS AFTER FELLING:

1. Wane:

                 The roundness of timber surface without bark.

2. Twists:

                Ends of the trunk are twisted in opposite directions.

3. Bow:

                Curve made along the face of timber due to shrinkage.

4. Cupping:

                     Curve formed across the width of trunk.

5. Checks: -

During felling of tree from stem internal stresses causes checks.

6. Splits:

Splits are the lengthwise separation occurs due to the reason of inappropriate handling of drawing stresses or forces.