Novatect S.r.l.

Can't say I've ever heard them doing it when they cool down, but when the sun hits them in the morning, it can happen. If they're mounted to an aluminum facia, that can also transfer noise when expand ... read more

Here is a product that is safe and non-toxic for waterproofing walls and even floors. They have various products for different needs. Hope this is helpful, good luck!  Product Details