Its not just insurance related but UK mortgage companies will not lend on a house with sprayed on insulation. The insurance is the lesser problem, unless they ask when the policy is set up then the insurance will find it difficult not to pay out a claim. I have never been asked what type of insulation is on the house when renewing house insurance to date. Getting a mortgage is the bigger issue as the required mortgage survey will point out the insulation type and then the house becomes a cash sale only with a lower value.
Appreciate the caveat. Not a problem in my specific case. A few factors - one, much warmer climate (southern US) so the cycling into colder temperatures that would allow condensation to build up isn't going on as often. Second, when they do spray foam here, they fully seal the space, which again gets to the part about temperature cycling and condensation.......fresh humid air will not be able to get to the area where water would condense. Basically, the system is designed to use foam, whereas more conventional fiberglass or blown in insulation would require ventilation. Foam is NOT appropriate for use in ventilated systems, but when I read the article however many months ago, that was what was being done. Third, the foam that has already been applied in a couple of places in the house was done properly, where there are no open gaps that the foam didn't reach (unlike the pictures I saw where a guy was able to reach up and feel the wood under the shingles). Fourth, as this is new construction, we are required to have inspections done in process, meaning if the foam were to be installed improperly, there would be a third party that (at least in theory) would be able to point out this to prevent things lie unfilled gaps. Fifth, I've already got a construction loan for the build.
Basically, from what I've read, the foam in that story was not applied correctly. And like anything, incorrect application can lead to issues.
That said, for anyone in colder climates and/or considering this with existing dwellings, your caveat is appreciated. I'd say that for those situations, the closed cell foam may actually be what is best. It doesn't expand like the open cell, and goes on like a thin layer. About twice the R-value, so is used in different situations than the open cell (often in conjunction with fiberglass). So it completely seals off the areas from any humid air that may be in the attic from a ventilated system. Think about it like a thick paint. It may be possible to use it with the open cell, which expands, but the closed would go against the structure, then the open on top of it. That may be a good solution that would prevent the ability of a system to trap moisture and cause rot.