You are reading a single comment by @andyfallsoff and its replies.
Click here to read the full conversation.
-
Ta - how difficult was it to do, was it ok? That might be the best option for us tbh if that saves the boards.
andyfallsoff-
Not hard as such but crawling in the 2 foot gap under the floor wasn't exactly fun and I never want to do it again. You also need a good flow of someone cutting the PIR to the right sizes then feeding them down to the person doing the fitting. The actual fitting is a bit of a pig because old joists are not perfectly parallel and using sticky expanding foam to fill gaps will ruin clothes/hair.
Sumo
We've done it, used 100mm PIR. Crawled under the boards rather than lifting them. Our place is 1930s and a lot of boards have split when we've lifted them. Might be able to save yours better but be prepared to find some reclaimed replacements.