Pete recently did an interview on BBC Radio 4 - You and Yours - which investigated a case history of failed cavity wall insulation.
I have recently been shown the survey results of a 'Damp Survey' which was done on a house in Yorkshire.
The house was stone built, and had all the usual issues of plastic paints on the stonework, cement mortar in the joints, cement pointing, and gypsum plaster internally.
Onee of the most experienced stonemasons in Yorkshire had been asked to check the house over and see if he could sort out damp issues. This was easily done, and he was engaged to re-plaster in lime, and sort out some damp walls that needed mortar removal and replacement with lime.
Internally, he organised better ventilation.
In the course of conversation with the clients, he was told 'We paid over £6,000 a year or two ago for a magnetic lampshade thing' that wa supposed to sort out the damp. We thought it worked at first, the bloke kept coming back and taking samples and telling us they were getting nice and dry.
My mason friend had sampled the walls at the same spots - not realising they had already been sampled - he showed the clients how wet they were. Sopping.
'So the magnet thing didnt work then?' they asked him..No, came the reply, it didnt. You just wasted £6,000.
Their house is now nice and dry and warm - and the magnetic lampshade no longer hangs from the ceiling - they felt very silly apparently, and were acutely embarassed that they'd fallen for such a gimimick. Ive asked for a bit more information and photos - if I ever get them I'll post them - but the lampshade thing had aquapol stamped on it..