Neighbors complain despite floor change

[Björnb22]

Hello.

We have received several complaints from neighbors that they hear loud thumping noises from our child. I went to the neighbor, and they invited me in to hear the noise. Just as they said, it is extremely loud when the child runs and jumps. You could also hear loud footsteps when walking. Even though it mainly happens during the day, I can understand that it bothers them given the noise level.

What the landlord did before was to replace the parquet and put thick foam underneath (about 1-2 cm thick foam). The parquet we got is 13mm thick. The apartment is from the "miljonprogrammet", and therefore I assume that the joists are made of lightweight concrete.

My question is, why does it sound so loud despite the foam, do you think? Could it be because the parquet is only 13mm thick and quite "flexible," which leads the pressure to the joists?

I have also occasionally seen some silverfish in the hallway, could it be that the joists are moisture-damaged and conduct sound more?

Grateful for answers and tips.

 

[Johan Gunverth]

Welcome to the forum!

Could it be that the landlord removed the sand under the old parquet and replaced it with self-leveling compound, foam, and laminate flooring? A classic mistake made during renovations in million program apartments that drastically worsens soundproofing.

 

[Björnb22]

Welcome to the forum!

Could it be that the landlord removed the sand under the old parquet and replaced it with levelling compound, foam, and laminate flooring? A classic mistake made during renovations in million program apartments that drastically worsens soundproofing.

Thanks!

I don't remember if they did that, but it is very likely that it was done. They laid a 13mm oak parquet over a fairly thick foam that was supposed to be a special kind that soundproofs a lot.

When you walk on the parquet, it bends just where you walk, do you think it could have something to do with it? That the foam had the opposite effect?

 

[Martin Siöland]

If you live in an apartment building, it's the landlord who should be contacted by your downstairs neighbor. It is their responsibility regarding the footstep noise. If the parquet is as unstable as you say and it's a click-lock, the floor is likely to break soon. What type of 1-2 cm underlay has been used? The instruction manual should include which flooring materials can be placed on top. The 13mm parquet might be too thin on top of it. Ask your landlord to check with the contractor who performed the work.
An example https://www.markvaruhuset.se/uploads/80b932a501ccc2e74eedc72fb9d371e7.pdf

 

[byggarätt]

Thanks!

I don't remember if they did, but it's very likely that it was done. They laid a 13mm oak parquet over a fairly thick foam that was supposed to be a special type that dampens a lot of sound.

When you walk on the parquet, it bends right where you walk, do you think that could be related to the issue? That the foam had the opposite effect?

Yes, the parquet acts like a drumhead when the sand that the old parquet lay on was removed, so the new floor became a drum that amplifies the sound! The foam might dampen a little, but what should have been done is to lay double floor gypsum and a thin foam!

 

[Björnb22]

If you live in a rental property, it is the landlord who should be contacted by your downstairs neighbor. It is their responsibility regarding the impact noise. If the parquet flexes as much as you say and it is click-lock, the floor will very likely soon break. What is the 1-2 cm underlayment that has been used? The instructions should include which flooring materials can be laid on top. The 13mm parquet may be too thin on top of it. Ask your landlord to check with the contractor who did the job.
An example [link]

Thank you for your response.

I will try to sort out these issues with the landlord.

 

[Björnb22]

Yes, the parquet acts like a drum skin when the sand that the old parquet was lying on was removed, the new floor became a drum that amplifies the sound!
The foam might dampen somewhat but what should have been done is to lay double floor gypsum and a thin foam!

Thank you for your reply.

So the sand should not be removed even if planning to lay foam?

 

[byggarätt]

Thanks for your response.

So you shouldn't remove the sand even if you're planning to lay foam?

No, but this is tricky because during the construction phase the sand gets contaminated and it must be 100% dry and clean... if moisture gets in, it's almost impossible to dry the sand without special equipment to 100% it must be sand that doesn't dust
Before self-leveling compound was used, sand was the thing
Today, you lay double layers of floor gypsum for soundproofing with a thin layer of self-leveling...