Dry Rot, Wet Rot and Woodworm

Posted by on Feb 8, 2010 in Building Surveying

These are the common names of some of the main diseases that affect timbers in buildings. They all have one essential pre-condition – dampness. Dry rot and Wet Rot cannot survive without a regular supply of moisture. The beetle responsible for Woodworm does not like dry conditions and is virtually extinct from modern centrally heated houses.

There is a fundamental flaw in the approach adopted by the “Timber Preservation” industry – they attempt to deal with the symptoms not the cause. In doing so they often recommend the most drastic of radical surgery which is expensive and damaging. A more appropriate policy is to deal with the root cause (invariably some form of water leakage) first, to dry out the building and to treat the results of fungal or insect attack only to the extent that actual structural damage has been caused. Toxic chemical treatments only have a very limited part to play where drying out cannot be assured or will take a very long time.

One of the driving forces behind the commercial Timber Treatment industry is the so-called “Guarantee”. Such guarantees are, in effect, worthless. As explained above, decay only results from moisture. In turn this can only result from some other failure of the building fabric which, invariably, is excluded under the terms of the guarantee. So-called “Specialist” firms, much beloved of building society mortgage valuers, offer these guarantees but if a fresh outbreak of rot occurs or an old outbreak reappears because of, say, a leaking gutter, they will point to their exclusion clauses. Millions of pounds worth of work are done every year which are entirely pointless and unnecessary, all for the sake of worthless guarantees.