Hello!
I have a bathroom in a basement where we've bitten the bullet and chipped out the old floor to find that a slab was poured directly on soil, sand, and clay. The ground moisture has been significant, and now, as mentioned, we've chipped out the floor and dug down about 50 cm!
But how should we build this correctly?
One suggestion has been geotextile at the bottom, 20 cm ISODRÄN, then geotextile again, and then pour a new 10 cm concrete slab with waterborne underfloor heating.
I think that sounds reasonable, as it provides drainage and insulation in one without adding significant height.
Does anyone have tips or experience with the same solution/construction project?
Regards,
Mats
I have a bathroom in a basement where we've bitten the bullet and chipped out the old floor to find that a slab was poured directly on soil, sand, and clay. The ground moisture has been significant, and now, as mentioned, we've chipped out the floor and dug down about 50 cm!
But how should we build this correctly?
One suggestion has been geotextile at the bottom, 20 cm ISODRÄN, then geotextile again, and then pour a new 10 cm concrete slab with waterborne underfloor heating.
I think that sounds reasonable, as it provides drainage and insulation in one without adding significant height.
Does anyone have tips or experience with the same solution/construction project?
Regards,
Mats
The construction itself is probably not faulty. The problem is more likely that, as I interpret it, you are doing this in isolation in one room, or have I misunderstood? You write that you have dug down 50cm. Do you want to gain 20cm in ceiling height since your construction is only 30cm? If this is only done in one room and you have a lot of moisture under the slab, there is a high risk that this moisture will instead seep into the surrounding walls - especially if you are using underfloor heating. Is it well-drained around the house?
The entire house has been externally drained and insulated with Isodrän and new drainage pipes, geotextile, etc., according to the rules of the art. I also want to gain some ceiling height since it was only about 185 cm from floor to ceiling before I broke up the floor. The room is located in a part of a basement built in 1955, where there are no adjacent rooms except along an inner wall. This inner wall borders a space that was built sometime in the 1980s, meaning with a properly drained gravel bed and concrete slab. That part of the house is nice and dry.