We need your help to replace a flooring construction from when the house was built in '71. After the elements froze on the ground floor, the previous owner left the room without surface layers after Anticimex did their part. We would like to achieve either underfloor heating or better insulation below. The room has also had a somewhat musty smell, so we're inclined to install new fresh chipboard at the very least. (There is a larger room adjacent that would also need the same treatment.) The room measures about 2.9x3.7 m.
Circled on the drawing clip. It's the room immediately to the right that would likely need underfloor heating as well. We heat the house with geothermal heating, so we are aiming for waterborne underfloor heating. Probably better insulation is required for underfloor heating. I've heard that at least 25 cm is needed to be able to install it, is this correct?
The construction is as follows: Concrete with cast-in studs, the studs seem healthy. Above the cast-in studs sit floor joists of 8x4.5 cm studs, these are supported on tongue-and-groove and masonite bits, creating an air gap at the bottom of about 5-6 cm. Between these studs, there are 7 cm thick insulation boards hanging on nails. Above this is chipboard, 3 cm thick.
So: Concrete with cast-in studs, on top of this are 8x5 cm studs supported with wood/masonite bits 5-6 cm above the concrete, then chipboard.
What would you replace this with?
Ground insulation boards and new studs or EPS concrete and leveling compound? Maybe cast and level over ground insulation? And do I need to chisel away the concrete to accommodate the proper insulation thickness?
