Roof timber rot from trapped moisture
Why it happens here
Spray foam applied directly to roof timbers seals the wood and stops it breathing. In Acomb's humid winters, condensation forms on the cold side of the foam and drips onto rafters and battens. Within a few seasons, the timber starts to soften and stain.
Our approach
We remove the foam with dry ice blasting, which does not add water to the equation, then test every accessible timber with a moisture meter. Affected sections are treated with fungicidal wash or cut out and replaced before we sign the job off.