Subscribe via RSS Feed

Wood Destroying Agents that Damage Timber Structures

July 10, 2017 0 Comments

Often failure within timber structures is more a result of poor maintenance and lack of knowledge of the characteristics and properties of the material itself. When wood is not well maintained, structural damage occurs as it is attacked by wood destroying agents – and often what the public (mistakenly) often refers to as pest damage.

There are a number of wood destroying agents that result in the failure of structural timbers. Some of these include:

  • Chemical delignification
  • Fungal decay
  • Wood borers
  • Termites

Below you’ll see a list of symptoms and causes for each of case of damage to timber buildings. However, these are not all inclusive, but rather, they are indicative of a wood infestation.

Chemical Delignification

Chemical delignification is the breakdown of lignin (the natural glue that binds wood cells together) through chemical action. Signs of chemical breakdown include:

  • The surface of the wood becomes hairy
  • Loss of strength resulting in deformation
  • Wood collapse

The damage is not caused by a ‘pest’. This is a chemical process.

Fungal Decay

Fungal decay is the microbiological degradation of timber caused by soft rot fungi and decay fungi. Signs of fungal decay on timber include:

  • Splits in timber sometimes in a longitudinal shape, but more usually cuboidal shape
  • Timber which has reduced both in moisture content and size as indicated by cracking either along or across the grain or by fibres coming apart in a stringy manner
  • Misshapen timbers, eg cupping and ridging of floorboards
  • Loss of strength resulting in deformation, and
  • Wood collapse

Again, this is not ‘pest damage’ – it is a fungal issue.

Wood Borers

Wood borers are wood destroying insects belonging to the order ‘Coleoptera’ which commonly attack timber. Signs of wood borer infestation include:

  • Adult beetles flight (exit) holes
  • Loss of strength in the structure resulting in deformation
  • On rare occasions, wood collapse


wood termitesTermites are wood destroying insects belonging to the order ‘Isoptera’ which commonly attack timber and are responsible for millions of dollars worth of damage every year to Australian homes. They are active in nearly every residential block and are a major threat to stored timber being used in during construction.

While they are commonly (and erroneously) known as White Ants, they are not actually related to true ants. They are a small soft-bodied, social insect that live in colonies that may consist of over a million individuals.

Signs of termite infestation include:

  • Abnormal depressions in the surface of timber, the gain may stand out and the surface of the timber be drawn in, and in other cases the timber may bulge out slightly
  • Loss of strength in the wood resulting in deformation, and
  • Wood collapse
Filed in: Trade Tips

About the Author:

Avatar for Construction Courses

Leave a Reply