Advances in in situ evaluation of timber structures

This paper discusses recent advances in nondestructive and semi‐destructive techniques that are used to evaluate the condition and mechanical properties of wood members in structures with emphasis on historic buildings. Traditional methods for assessing the condition of timber are generally nondestructive, but may require probing or removal of small samples for species identification. Nondestructive techniques are useful for rapid screening of timber for potential problem areas or implying internal conditions, but typically are not particularly reliable for identifying material properties. Semi‐destructive techniques require extraction of a small specimen for subsequent testing to determine elastic and strength parameters while preserving the integrity of the structural member. Both nondestructive and semi‐destructive techniques are powerful aids to building conservation decisions.