Is there any new advice on cavity wall insulation?

[Piscivorus]

We live in a detached Edwardian house by the sea which has always been deemed unsuitable for insulation with whispers about damp as a possible problem.

There is now a new government funded scheme to insulate "difficult" buildings; this includes coastal properties and we are now swamped in people wanting to survey, do any remedial work (by which they mean remove sand and crap from the cavities) then insulate with the newest insulation material. Apparently the one suitable for coastal use is little silvery balls (I presume some sort of coated polystyrene) but they are coated in PVA so they stick to each other and don't compact as much as the older stuff so allow any sand or moisture to drain down through.

We have damp in just 2 areas, one the surveyor thinks is a hole in the pointing so easily remedied when they do the work, the other is a bit more problematic as it could be rubble in the cavity or damp penetrating the sandstone bay which they say may be solved but will definitely not be made worse.

It would be good to reduce the bills but we don't want to cause any problems. Does anybody have any thoughts on whether this is a good idea please?

Bumping for you.

I had my home surveyed a few weeks ago. As they damp proof course can't be seen the house was not suitable.

Thanks for the replies. Bumping for any more please

Doesn't anyone know anything about this? Waaaah!

I have a little insight which may be a dangerous thing, but here goes.

The mechanism by which cavity wall insulation is covered for faults is insurance-backed, i.e. if there's a problem down the line, the insurance policy (sold with the insulation) should cover it. Every insurance policy I've seen says that properties in exposed/coastal areas are not covered.

So, this company may have developed a new material which is suitable for coastal areas but unless the insurance policy which backs it up specifically refers to coastal properties, you're stuffed if you have a problem, since insurance companies will always find a way to exclude your claim. So, read the policy carefully.

I haven't answered your technical question regarding the insulation because I don't know, but the company should be able to show you places where it's been used successfully (or not). I really don't like the sound of 'rubble in the cavity' though, and again this is something that an insurance company would jump on as a reason not to pay out.

Thanks fresh. I think their suggestion was this rubble was some bits of broken brick and accumulated sand which is breaching the cavity and causing the damp. The new government scheme which insulates your house for free now includes clearing the cavities before insulating as sand getting in them is a big problem here. In effect though, that problem would be remedied before insulating.

I'm assuming these government funded schemes must be backed by insurance that covers the houses they are aimed at, mustn't they? This scheme is specifically marketed at houses that are at the coast, houses more than 2 storeys high and others that were "problems" on the initial insulation plans. It is definitely something centrally funded as we have had British Gas and 2 other companies round telling us the same story about government funding.

Government funding means that there's money to be made by the companies, just like in the original scheme. This means they will be very keen to sign you up. I'm very very cynical about this sort of thing and I may be being completely unfair, but if it were me I'd be reading the small print on the insurance policy very carefully.

And I wouldn't let British Gas near my house under any circumstances!