grandizer

I'm interested in this point about detecting leaks through foam insulation. I've read this claim by demilec, icynene, etc that water just passes right through so you find a leak right away.

But I've heard anecdotal evidence to the contrary - it's just a big sponge and destroys hangs on to a huge amount of water.

What's the deal on this? This is a main reason we haven't done a hot roof from foam.