Does anyone have any thoughts on the following problem.
I've just put down 100mm polyisocyanurate boards on the concrete floor in preparation for screed. Problem is insulation was stored in the house for last 6 months and over that period its bowed so instead of straight boards they are curved and proud in the middle by about 5 cms (a bit like a dome). When you step on the boards they crack and this straightens them but not completely so when they are down on concrete and you walk on the insulation, its got a bounce to it. Screed man is reasonably happy its ok - he says that weight of screed should push it down but obviously it would be better if it was straight. We had the man from board manfuacturer round who says its good enough in his opinion (nothing in writing though). Apparently its also normal for boards to change shape if they are exposed to low temperatures. The boards are also from builder's merchants, not seconds or similar and were stored flat indoors.
What should we do? I am possibly being paranoid expecting boards to be flat but I am concious of cost of putting right any possible problems. I have asked manufacturer to swap the boards but he said this amount of deflection is within tolerance level set by British Standard(?).
I've just put down 100mm polyisocyanurate boards on the concrete floor in preparation for screed. Problem is insulation was stored in the house for last 6 months and over that period its bowed so instead of straight boards they are curved and proud in the middle by about 5 cms (a bit like a dome). When you step on the boards they crack and this straightens them but not completely so when they are down on concrete and you walk on the insulation, its got a bounce to it. Screed man is reasonably happy its ok - he says that weight of screed should push it down but obviously it would be better if it was straight. We had the man from board manfuacturer round who says its good enough in his opinion (nothing in writing though). Apparently its also normal for boards to change shape if they are exposed to low temperatures. The boards are also from builder's merchants, not seconds or similar and were stored flat indoors.
What should we do? I am possibly being paranoid expecting boards to be flat but I am concious of cost of putting right any possible problems. I have asked manufacturer to swap the boards but he said this amount of deflection is within tolerance level set by British Standard(?).
