Trapped moisture causing roof timber rot
Why it happens here
Open cell foam is vapour-permeable but it still holds liquid moisture against the timber. In Combe Pafford, the coastal humidity means the foam stays damp for longer. Over years, that moisture rots the rafters and roof deck.
Our approach
We remove the foam, measure moisture in the timbers, and treat any rot with a fungicidal wash. If the rot is structural, we replace the affected sections. We then fit a vapour barrier in the correct position so the problem does not come back.