ᐅ How to Soundproof the Floor/Ceiling in a Multi-Family Building?

Hello,

A four-family house is going to be completely renovated from the ground up. There will be no more tenants.

According to the former tenants, it was quite noisy inside, which I think is probably due to the intermediate ceilings. My first idea would be to install about 4cm (1.5 inches) of screed/concrete in each room on top of approximately 2cm (0.75 inches) of 035 styrofoam boards. Special biodegradable insulation panels costing 58€/m2 (square meter) are beyond my budget, so I need a good and cost-effective solution for about 300m2 (square meters).

Has anyone had experience with this?

Thanks and best regards,
phi77

Good evening,

phi77 schrieb:

A four-family house is to be completely renovated from the ground up. No more tenants inside.

Is this being supervised by a professional or an architect?

phi77 schrieb:

According to the reports from former tenants, it was very noisy; I think it’s probably due to the intermediate ceilings.

Believing that is like praying in church 😉 It could just as well be due to the thin interior walls, lack of soundproofing in the stairwell, or... well, many other possibilities.

phi77 schrieb:

Has anyone here had experience with this?

Ask someone who knows about this (an on-site inspection) before you throw “good” money after “bad,” or in other words: end up paying twice.

Regards, Bauexperte

...Expert Inspection Unaccompanied.
It’s an old village house from 1900, with wooden plank flooring.
I’m doing everything myself.
The stairwell is solid construction and does not transmit much noise.
The tenants on the ground floor said that you can hear everything from upstairs,
which is why they eventually looked for another apartment.
Here, I would like to do something only to the intermediate ceilings,
but I cannot renovate the whole house.
What kind of build-up would be possible?
Is my proposal of screed and polystyrene insulation a good idea or not?

Regards, Phil

Styrofoam will probably not help you much.
Soundproofing measures should always follow the soft-hard-soft principle. Hard-soft-hard.
That would mean concrete floor–mineral wool–screed.

Whether this will actually help you is questionable. The cause needs to be clearly defined first. Otherwise, it’s a guesswork approach.

If you know the reason, then you can consider appropriate measures.

Do you currently have no screed installed? Your concerns are actually typical for somewhat older houses.

Have you checked for sound transmission? For example, try playing a radio on the floor below and listen carefully.

Edit: Looks like we wrote at the same time. If the house is that old, would the ceilings even support such a screed? They are probably still wooden beam ceilings.

Yes, wooden beam ceilings. A radio is a good idea, but I’m only officially allowed to move into the house and do whatever I want once the notary and land registry process is fully completed. So for now, I’m just mentally walking through the house and trying to use the time to calmly address things like this ;o)

The hard-soft-hard layering concept makes sense, since 035 EPS (expanded polystyrene) is actually quite firm over the surface area...

Or here’s another idea—I could carefully remove the floorboards, add 2-3cm (1 inch) of mineral wool or fiberboard insulation, then put the floorboards back on, sand them down, and finish with hard wax oil... that would preserve the character of the house. I think this step would be noticeable when walking on it.

Concrete floor – mineral wool – screed is of course the premium option, but the overall height buildup might become too high. What exactly is the difference between a concrete floor and a screed?

But I couldn’t pour the screed directly onto soft mineral wool, right? Or do you use a firmer type of mineral wool boards for that? Because in the middle of the room it would probably compress and create stress otherwise.

Best regards, Phil

First of all, my personal opinion: invest money, hire a professional, and do it properly. Anything else is shoddy work and in my view leads to more problems than solutions.

Step 1: Identify the exact problem: airborne sound, impact sound, or both? Based on experience, in older buildings with wooden beam ceilings, impact sound is usually the more critical issue. In existing wooden beam ceilings, airborne sound is generally not a problem once impact sound is under control. You can forget the amusing story about the radio.

Step 2: What exactly does the existing ceiling and floor structure look like? Beam dimensions and spacing, single-layer raw ceiling, multi-layer raw ceiling with or without additional mass, possibly hollow floors; what does the existing suspended ceiling (reed mats with clay plaster?) or its connection to the beams (rigid, flexible) look like? If there is additional mass in the cavities, what is the surface weight, and most importantly: what is its composition? (Keyword: contaminants) How are the bordering building components constructed and connected (external walls, possibly half-timbered structures)?

Only then can you start considering possible measures. But simply adding screed and polystyrene insulation won’t work on a wooden beam ceiling, at least for structural reasons alone; then you’ll also have to raise door frames, and so on. In principle, reinforcements can be made to the supporting structure or the suspended ceiling. What is feasible in your case must first be clarified in the two steps described above. Preferably by a professional. In the Munich area, I even have a recommendation for you.