Diseases of Timber:

A perfectly seasoned timber obtained from a sound matured tree and placed in a dry and well ventilated place or entirely immersed in water can last for several years. But when timber is confined to a place where it is liable to be subjected to alternate dry and wet conditions or when used in a dark, damp and unventilated position, then it gives birth to the following two common diseases:

(i) Dry rot

(ii) Wet rot

(i) Dry rot:

This disease in timber is caused due to the lack of ventilation. Such situation promotes the growth of fungus which eats the fibres of timber and reduces them to dry powder. The growth of fungi accelerates the progress of dry rot but the origin of the disease is due to the decomposition of sap in the timber first and then this decomposition supplies food for the growth of fungi. This disease is highly infectious and causes tremendous destruction of timber. This disease may develop in seasoned timber, unseasoned timber or unseasoned timber treated with preservatives. This disease is common in warm cellers, unventilated wooden floors, basements, ends of timber built into walls without protection or ventilation, timber piles, etc. This disease can be detected by tapping at one end of timber post or log and hearing the sound on the other end.

If a distinct sound is heard then it indicates a sound timber and if a dull sound is heard then it is a sign of decayed or diseased timber.

The following measures can be taken to prevent or eradicate this disease:

(a) By following free circulation of fresh air.

(b) The portion of the wood which is attacked by dry rot should be cut off and remaining portion painted with copper sulphate.

(c) By exposing the infected portion to sunlight and sweeping off fungus.

(ii) Wet rot:

This disease is the result of decomposition of timber caused by damp and moisture. This disease is further induced by alternate wet and dry conditions. The portion of timber attacked by wet reduces to a grayish brown powder. In this disease, the timber is first decomposed while wet and then it scales off when it dries. This disease can develop in a timber whether dead or alive. All types of timber used in uncovered situations is likely to be exposed to rain and hence subjected to wet rot.

Find More About,

Timber
Structure of a Timber Tree
Properties or Characteristics of Timber
Defects of Timber
Diseases of Timber - Dry and Wet Rot
Decay of Timber
Seasoning of Timber
Methods of Seasoning of Timber
Preservation of Timber