Timber Survey is an assessment of how structural timber and joinery have been affected by biodeterioration mechanisms, namely:

  • Wood boring insects
  • Wood decay/spoiling fungi
  • Structural failure (or response) resulting from the above or from alteration is also assessed.

In Practise

  • Emphasis is placed on determining whether the decay organisms are alive, or if an environment exists that could support them.
  • Extent of decay is quantified, using various methods as the situation requires (such as micro drilling).
  • Timber species and quality are established.
  • In situ timbers visually strength graded to BS4978 (softwood) and 5756 (hardwood).

The Report

Forms the basis of a building specification. It will include schedules of timber replacement and repair where necessary. When working with historic/protected buildings, recommendations are based on

  • The biological capabilities of the biodeterioration organisms,
  • The physiology/anatomy/structure of the building materials,
  • The ultimate design and structural demands to be placed on the elements.

The objective is to retain as much of the original fabric as possible.


Diagnosing decay in embedded bearings and concealed sections of timber often present difficulties. One way of accurately achieving this is with a micro drill.