Pete recently did an interview on BBC Radio 4 - You and Yours - which investigated a case history of failed cavity wall insulation.
This was diagnosed by a PCA member firm of rising damp wallies as rising damp on a wall in London. Richard went to have a look, and took up a bit of floor. The wall underneath was bone dry. The plaster was gypsum, and suffering a bit of condensation. PCA wanted to inject and replaster everything. Cheap solution - a bit more ventilation in the cupboard. Expensive solution - knock a bit off and replace with lime plaster. Cost - couple of hundred pounds. All now inexpensively sorted without recourse to any rising damp treatments and snake oil provided by property care association members with their phoney CSSW and CSRT 'qualifications' that have no academic credibility.
This is a magnificent building with what were described as major damp issues. Using thermal imaging, we showed how water was penetrating, and directly related to faulty drainage from the roof. So simple - there was no 'rising damp' as claimed, and the problem was actually fixed in a matter of half an hour, by repairing a broken cast iron downpipe.
This was a survey we did recently in which the owners had 'renovated' the building - using plaster dabbed plasterboard on single brick walls. These were cold, and the dabs were heat sinks - cold bridging, so that the wall developed 'rising damp' symptoms on all the walls that were dabbed. The solution was very simple - removal of all the dabbed plasterboard, and thermally efficient dry lining, using steel framing, insulated with sheepwool.