Roof rot from trapped moisture under foam
Why it happens here
Spray foam seals the roof deck and blocks the ventilation path that older roofs rely on. In New Addington's damp climate, moisture from the house condenses on the cold timbers and cannot escape. Over a few winters, the timber starts to decay.
Our approach
We remove the foam, inspect every rafter with a moisture meter and thermal imaging camera, and treat or replace any decayed timber. Then we restore the original ventilation path so the roof can dry out.