Hello!
I have a house from '69 where we have a large recreation room in the basement.
When we moved in, it smelled very damp, so I tore out the floor. It turned out to be raised with wood and then chipboard directly against the concrete. As insulation, they had used regular yellow insulation directly on the slab, so the chipboard sheets were almost twice as thick in some places.
I tore everything out immediately when we moved in 2011, and since then, the basement hasn't smelled damp.
Now it's clean, but there are embedded wooden joists roughly cc 60.
Now to my question, how should I lay a new floor? It's about 150mm that it needs to come up to be at the same height as the rest of the basement. At first, I thought of laying a Platon mat, then install new joists with ventilated skirting boards, but I think the floor is too uneven to lay a Platon mat on. Then I got the advice to install joists on the concrete with plastic spacers, then insulate with rigid foam that doesn't touch the slab, ventilated skirting boards, and a Pax fan.
Maybe a vague post, but I hope you understand what I mean.
The best option is probably to use a Nivell or Granab floor, but they are a bit pricey. The advantage is that it doesn't matter if the slab is uneven, and no insulation or organic material will be in contact with the concrete. They can also be combined with underfloor heating if desired.
