Our timber/ damp specialist tells us if we put this membrane on an external wall it will channel the water to the ground and "solve" our damp problem.
But i said the water's finding it's own way to the ground anyway. I'm worried it will stop the wall breathing properly and drying out when we fix what we know is the actual cause of the damp (cracked and leaky steps).
When i said all this he said it was actually a cosmetic thing - it would make the wall look better (so not a "solution") at all.
Anyone know if these things actually do anything or are they a bit of a con?