Hello.
I am wondering if there are any smart and economical solutions for leveling a concrete floor under the joists. Not the entire floor (self-leveling compound would be too expensive, the room is nearly 300 square meters), but under the joists and a few centimeters outward. I'm considering whether one could create a sort of base of concrete where the joists will be placed. Similar to when you make the foundation for a wall. Do you have any tips?
I am wondering if there are any smart and economical solutions for leveling a concrete floor under the joists. Not the entire floor (self-leveling compound would be too expensive, the room is nearly 300 square meters), but under the joists and a few centimeters outward. I'm considering whether one could create a sort of base of concrete where the joists will be placed. Similar to when you make the foundation for a wall. Do you have any tips?
Hello!
If the goal is to achieve a flat and nice floor "on top" of the joists, you don't necessarily need to level the concrete floor. There are a few floor systems (Nivell, Granab, and perhaps more) that consist of joists with accompanying adjustment screws. These are not dependent on a flat subfloor but are adjusted to the correct height and level using the adjustment screws. On the joists, you can then lay, for example, chipboard flooring and then a surface layer or an unsupported top floor, such as 22 mm parquet or floorboards with sufficient thickness.
A tip if the above is interesting to you: it's important to install the adjustment screws according to the manufacturer's instructions. In the early days of these floor systems, some mistakes were made, which led to sagging floors and shaking bookshelves, mainly at the outer edges of the rooms.
If the goal is to achieve a flat and nice floor "on top" of the joists, you don't necessarily need to level the concrete floor. There are a few floor systems (Nivell, Granab, and perhaps more) that consist of joists with accompanying adjustment screws. These are not dependent on a flat subfloor but are adjusted to the correct height and level using the adjustment screws. On the joists, you can then lay, for example, chipboard flooring and then a surface layer or an unsupported top floor, such as 22 mm parquet or floorboards with sufficient thickness.
A tip if the above is interesting to you: it's important to install the adjustment screws according to the manufacturer's instructions. In the early days of these floor systems, some mistakes were made, which led to sagging floors and shaking bookshelves, mainly at the outer edges of the rooms.
Hello and thank you for the response.
No, the purpose is really just to get the framework stable and without gaps underneath. I will be installing a floor inside with a completely different construction (ground board/2xmdf/underlay foam/laminate) that will not have any contact with the walls (there will be musical activities in the space, and after consulting various acousticians, this is the best solution for my space, however, I need a flat surface to lay the studs on that will be against the floor to minimize sound leakage/intrusion that way).
I'm looking for a solution where I level only the surfaces for the four wall frameworks.
I have looked at Nivell, but I'm fairly sure that would result in one big bass drum/resonant membrane that worsens the problem with low-frequency sound leakage. That type of floating floor usually needs an extreme mass to be effective far down in the frequency range.
No, the purpose is really just to get the framework stable and without gaps underneath. I will be installing a floor inside with a completely different construction (ground board/2xmdf/underlay foam/laminate) that will not have any contact with the walls (there will be musical activities in the space, and after consulting various acousticians, this is the best solution for my space, however, I need a flat surface to lay the studs on that will be against the floor to minimize sound leakage/intrusion that way).
I'm looking for a solution where I level only the surfaces for the four wall frameworks.
I have looked at Nivell, but I'm fairly sure that would result in one big bass drum/resonant membrane that worsens the problem with low-frequency sound leakage. That type of floating floor usually needs an extreme mass to be effective far down in the frequency range.
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It seems like I misunderstood your question, I thought it was a floor construction that was going to be built.
If I understand correctly, you want to build a smaller room within your existing larger room and seal the gap between the underside of the wall and the top of the existing (uneven) concrete floor?
In that case, I would set up the four wall sections (the nailed-together framework) and slide a strip of 0.2mm construction plastic underneath so that the underside of the sills is covered. Perhaps staple the plastic so that it stays in place. Shim the wall sections so that the wall frames are level. Then mix a stiff mortar (perhaps fine concrete) and then tuck it under the sill with a trowel. It should become soundproof. The plastic protects the sill from the moisture in the mortar.
If I understand correctly, you want to build a smaller room within your existing larger room and seal the gap between the underside of the wall and the top of the existing (uneven) concrete floor?
In that case, I would set up the four wall sections (the nailed-together framework) and slide a strip of 0.2mm construction plastic underneath so that the underside of the sills is covered. Perhaps staple the plastic so that it stays in place. Shim the wall sections so that the wall frames are level. Then mix a stiff mortar (perhaps fine concrete) and then tuck it under the sill with a trowel. It should become soundproof. The plastic protects the sill from the moisture in the mortar.
If you're just going to level the floor joists, it's probably easiest to mix a batch of fine concrete and lay out a strip to place the joists in, then tap them down until they're level. Let the concrete cure/dry, and the joists will be even, allowing you to drill and plug a couple of screws into the floor so they stay in place.