Hi, writing here for the first time.
I am renovating the hallway and want to have underfloor heating + tiles.
The current floor consists of a concrete slab, 70 mm joists and fiberglass, 25 mm tongue-and-groove wood, thin masonite, and thin laminate.
There is an unfinished basement under the slab that stays around 13°C in the winter.
I have concluded that it must be cleared down to the concrete and built up to reach the level of the current floor and make space for underfloor heating, tiles, and reinforced self-leveling compound.
The question is, am I making a mistake if I cast 50 mm lightweight concrete boards on the concrete floor, followed by a reinforcing mesh, electric heating cables, self-leveling compound, etc.?
The idea is that it should insulate a bit against the basement, not weigh too much around 500 kg, and be as cheap as possible?
I am renovating the hallway and want to have underfloor heating + tiles.
The current floor consists of a concrete slab, 70 mm joists and fiberglass, 25 mm tongue-and-groove wood, thin masonite, and thin laminate.
There is an unfinished basement under the slab that stays around 13°C in the winter.
I have concluded that it must be cleared down to the concrete and built up to reach the level of the current floor and make space for underfloor heating, tiles, and reinforced self-leveling compound.
The question is, am I making a mistake if I cast 50 mm lightweight concrete boards on the concrete floor, followed by a reinforcing mesh, electric heating cables, self-leveling compound, etc.?
The idea is that it should insulate a bit against the basement, not weigh too much around 500 kg, and be as cheap as possible?
You'll need to calculate that. Eps concrete costs a bit. Another option is to glue 50-60 mm eps insulation with self-leveling adhesive at the bottom for better insulation and cheap filling. Then self-level with fiber-reinforced self-leveling compound including heating cable on top of that.H Hankr said:
Yes. If you have a layer of self-leveling compound on top, it distributes the pressure. It's probably achievable even with the simplest EPS blocks. In the laundry room, I have tiles glued directly on EPS, but it's probably slightly harder EPS. LK floor heating has systems with EPS panels. Check them out...H Hankr said:
Why not use ground insulation boards like the ones used under houses? They are very strong and easy to cut and work with. I have a floor at home made this way. On top of this, there are a few cm of concrete with a reinforcing mesh in it, and on top of that, tiles.
But that's probably not a construction that any manufacturer supports...H Hankr said:
Cast with EPS concrete and self-level at least 20mm, then lay tiles.
If you absolutely want boards at the bottom, then cast with concrete or screed.
The advantage of plastic boards is that they insulate much better than EPS concrete.
Otherwise, I would probably have chosen EPS concrete, but now the space for insulation is minimal...
Otherwise, I would probably have chosen EPS concrete, but now the space for insulation is minimal...
That looks interesting. Does tile adhesive work as glue in this case? Do you need to secure the foam insulation to prevent it from floating up during the second leveling? The electric cable holds a max of 70C. Do you need spacers or similar so it doesn't rest against the foam insulation?L largab said:
Can't answer all your questions but they do float. When you glue them with something suitable, to get them snug against the concrete, you just place stones on the sheets.
That's what I did and it turned out great.
That's what I did and it turned out great.