Hello.
I have an old indoor garage that is being converted into a room. Thick concrete slab that unfortunately, for my needs, was too sloped. Decided to jackhammer out half of the floor and pour new concrete to level it, due to ceiling height.
Now I'm in a bit of a hurry to finish and want some insulating concrete. Therefore, I have chosen a self-drying EPS-cement/concrete. The question is how should the substrate be prepared?
Is it okay if a little dust, stone, concrete residues remain? I've roughly swept most of it now. In some cases, it is said that it must be clinically clean and primed. In other cases, it is said that you can just lay some leave and then pour the concrete.
I will pour about 8 sqm of 40mm EPS-cement, then 20mm self-leveling compound on top.
I'm not getting anywhere with this. I've searched a lot, but haven't found anything.
Finja, for example, says that the surface should be cleaned thoroughly.
But it's very rough and uneven, which is good for the concrete to adhere to.
I plan to use EPS-350 from Bauhaus.
I have an old indoor garage that is being converted into a room. Thick concrete slab that unfortunately, for my needs, was too sloped. Decided to jackhammer out half of the floor and pour new concrete to level it, due to ceiling height.
Now I'm in a bit of a hurry to finish and want some insulating concrete. Therefore, I have chosen a self-drying EPS-cement/concrete. The question is how should the substrate be prepared?
Is it okay if a little dust, stone, concrete residues remain? I've roughly swept most of it now. In some cases, it is said that it must be clinically clean and primed. In other cases, it is said that you can just lay some leave and then pour the concrete.
I will pour about 8 sqm of 40mm EPS-cement, then 20mm self-leveling compound on top.
I'm not getting anywhere with this. I've searched a lot, but haven't found anything.
Finja, for example, says that the surface should be cleaned thoroughly.
But it's very rough and uneven, which is good for the concrete to adhere to.
I plan to use EPS-350 from Bauhaus.
As you may see in the pictures, I haven't chipped out the entire floor, just slightly more than half.
The plan is to cast EPS up to the same level as the existing floor and then use self-leveling compound on top of that to achieve an even surface.
The entire floor will then have waterborne underfloor heating via EPS boards.
The house is built on bedrock and hasn't shown any signs of moisture since it was built in 1962.
The plan is to cast EPS up to the same level as the existing floor and then use self-leveling compound on top of that to achieve an even surface.
The entire floor will then have waterborne underfloor heating via EPS boards.
The house is built on bedrock and hasn't shown any signs of moisture since it was built in 1962.
I would have vacuumed thoroughly and primed before the new casting
However, I'm not an expert but want to believe that the new material doesn't really adhere and just lies like a crust on top...
However, I'm not an expert but want to believe that the new material doesn't really adhere and just lies like a crust on top...
It's tricky to get the eps to adhere to the substrate. I succeeded in one room and failed in another. What might be most important is ensuring that the eps cannot float up when you apply the self-leveling compound, as it's not ideal if it starts to penetrate under the eps.
I drove a fairly large number of screws into the substrate to which I attached the reinforcement mesh for the self-leveling compound, so the mesh pressed the eps in place.
Keep in mind that there should be quite a substantial amount of self-leveling compound over the eps.
I drove a fairly large number of screws into the substrate to which I attached the reinforcement mesh for the self-leveling compound, so the mesh pressed the eps in place.
Keep in mind that there should be quite a substantial amount of self-leveling compound over the eps.
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Hmmm good thoughts. Another thought is to cast with coarse concrete instead and wait a few weeks instead.
The reason for Eps-cement is mainly that it is self-drying so I can finish faster.
The reason for Eps-cement is mainly that it is self-drying so I can finish faster.
Pumba: When you say that the eps can't float up, do you mean that since it's so light and if it hasn't "melded" properly with the substrate, it lies like a floating "cork piece" sort of?
About right, self-leveling compound does tend to sneak in where you least want it, so there's always a little risk that it finds its way under the EPS concrete, and then there's a big risk it lifts, both pros and cons. I used it when I made a mistake in a room, a bucket of self-leveling compound with higher water content so it seeped down and filled voids under the EPS, then I waited an hour and applied self-leveling compound over it as usual, which glued the first round of EPS a bit.
In your case, I would probably try to get the EPS as level as possible and then lay the grooved boards directly on top and skip the self-leveling compound.
In your case, I would probably try to get the EPS as level as possible and then lay the grooved boards directly on top and skip the self-leveling compound.