I'm renovating my bathroom and I need to insulate the floor. It's a concrete slab with 2x4 joists set on one brick piers.
The home was built 50 yrs ago.
There was no insulation at all in the floor. And the bathroom is freezing in the winter and hot in the summer.
If I slide in pieces of rigid foam board will I have problems with condensation rotting out the 2x4s?