My son has a flat roofed extension (hate them myself) this has been recently reroofed. There are signs of damp inside where the extension wall meets the original house wall. The signs start about 1 foot above the ground and extend for about 4 feet. Any suggestions as to where the damp may be coming from and/or how to trace it? TIA
================== What kind of flashing have you got on the new roof / original wall joint? If it's 'Flashband' adhesive flashing then that could be the source of the trouble.
Cic.
Almost 20 years ago a neighbour had an extension built against a west-facing cavity wall. The outer leaf of the original wall was of reconstituted-stone-faced-concrete blocks.
When it rained the wall of the 'new' room which had originally been the outside wall of the house became wet in the way you describe.
Thinking there was a problem with the roof my neighbour called in a roofing contractor. The contractor found no obvious fault with the roof (not his work!) and wondered whether the rain was simply tracking through porous outer leaf of the wall. He suggested that the wall above the extension should be 'painted' with one of those clear, waterproofing damp seal solutions.
I think the whole wall was given a couple of coats and it solved the problem.
HTH
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