A number of years ago the "warm homes scheme" supplied thick silver foil panels to me to put behind the radiators on external walls. I have been having problems with damp walls behind radiators only and suspected a new damp course was needed. Damp behind all the radiators that had been fitted with the foil. Taking the bull by the horns in the worst room I removed the radiator and took all the damp plaster off the wall. Behind it the brickwork is completely dry. No sign of damp anywhere even when I removed the skirting board and can see to the ground. No smell of damp either since the plaster removed. This must have been condensation and I suspect all the other rooms are the same where the foil is fitted. Has anyone experienced a similar problem like this with the foil. Maybe someone can provide the answer.

needawin, October 2011

Extremely unlikely to be damp course(DCP) problem or it wouldn't just be behind the radiators.

Have a look at the rear of the foil panel if plastic type material it could be that sweating causing the damp through lack of air circulation.

Something you could try.
Slide a hardboard panel of same size down between wall and foil panel to isolate the panel from the cold wall, it may cure it and as the board is not plastic should be sweat free. Check it after around 3-4 days

If this doesn't work then contact local council Engergy saving or planning department tell them the problem and is there any advice they can give.

Bob, October 2011