Look at the image below:
Now look at this one:
And finally this:
All of these images are taken from decayed timbers found in different houses that suffered from damp issues of one form or another. However, only one of these properties was suffering from an outbreak of true Dry Rot (Serpula Lacrymans) and the other two were affected by the less serious wet rot.
Can you guess which? Well, probably not just from looking at these images shown here, but my point is that it is incredibly important to ensure that an accurate diagnosis is made in order to distinguish between wet rot and dry rot, as the remedial treatments differ greatly in both cost and disruption. Cuboidal cracking and darkening of the timber is a common symptom found in timbers being attacked by both wet rot and dry rot, but there are a number of other factors that differentiate the two.
Be sure that whoever is making your timber and damp diagnosis is experienced and able to correctly identify these factors along with being fully qualified and impartial, having no financial interest with the subsequent prescription for remedial treatment. A full list of qualified and independent damp and timber specialists can be found through the Property Care Association
For those curious as to which was the Dry Rot infection, it was in fact the third image. The second image was also incorrectly identified as being Dry Rot by a contractor working at the property. It was an honest, if not clumsy mistake as he thought that the creamy white substance on the edge of the timber was a fruiting body. On closer inspection by a CSRT qualified surveyor, this turned out to be wood adhesive!
Know your rots and make sure whoever is involved with your project is not talking “Tommyrot”!