Soundproofing - High density insulation/mineral wool 40-60kg/m3

[arcile]

Hi!

I imagine these might be questions you also face.

I'm about to soundproof the ceiling in an apartment from footstep noise and conversations from above.

I'm planning to use this principle:
http://www.soundstop..._solution_1.php

- From above: Acoustic hangers/genie clips, high-density insulation, two layers of drywall with sound absorbent in between

But the issue is that I seem to have trouble finding mineral wool/insulation with 40-60kg/m3. Preferably at a somewhat reasonable price too, the site I found offers Tecsound T50 for 500 kronor for 7 square meters, and insulation for 300 kronor for 8 square meters.

Does anyone know if any good insulation is available here in Sweden?

It seems like the range is significantly larger abroad.

Best regards,
Daniel

 

[roland53]

Rockwool sells high-density impact sound boards, but these are not usually stocked by the average building materials retailer and are instead ordered upon request. Rockwool does not split the pallets, so if you are unable to negotiate with your building materials retailer, you should be prepared to buy a whole pallet.

 

[Björn Melander]

I am familiar with the system you are linking to but have no experience or measurement data on the system. Instead, we use Vibratec's system (IsoHangers). The mineral wool should not be of high density. Flexibatt has adequate flow resistivity for the purpose.

 

[arcile]

Thanks for the response Björn, I'll take it to heart!

Do you also usually work with double plasterboard constructions with Green Glue or QuietGlue in between? What is your experience, does it work well?

 

[Björn Melander]

Greenglue is widely used, especially in the USA. The product has been tested at Riverbank and shows improved values in the lab in any case. However, we never use this for walls with many layers of drywall (extremely expensive). Instead, we use NoiseKiller between the ceminwood boards when building floating rooms within rooms. The screws are used only during curing time and are then removed. The main idea is to mechanically decouple the layers from each other.

In response to your question regarding hangerstak, I don't think it's necessary to use GG or similar products.
A question, has there been any insulation measurement of the floor structure? If it's a wooden beam structure, you may need more than two layers.

Some tips: screw sparsely into the ceiling to get more attachment points and simplify the mounting. For more than two layers, replace one layer of drywall with K-plyfa. Remember to leave a gap for sealing between the new drywall ceiling and the existing walls.

 

[arcile]

Thanks again!

I haven't done any insulation measurement, but looking at the construction drawings, it seems to be cement/concrete. It is an old house from the 1920s.

Sure, you only leave a gap at the top layer, the second layer can be allowed to go all the way to the wall?

 

[Björn Melander]

You should have a gap at all joints. You should use a backing rod first because otherwise the joint will collapse over time. An alternative is to use expanded sealant strips, but it must be of the "heavy" type with closed cells. So not the kind that is commonly used for window seals.

 

[arcile]

I'm a bit stuck in worry about the structural integrity and material of the roof, as it's an older building from the 1920s.

The roof seems to be made of "floor structure of porous concrete," then some form of reinforced reinforced concrete slab with a span of 2 meters.

It's quite heavy drywall that needs to be hung,

- Will the mounting hold, is it something I should investigate more, and if so, how?
- What screws should be used to ensure the best hold?

 

[Finndjävel]

High-density insulation for soundproofing is completely useless. It's extremely expensive, and the soundproofing improvement is barely noticeable. 40-60kg/m3 is nothing to write home about when it comes to soundproofing. Use regular cheap insulation as an absorbent and then apply multiple layers of drywall instead. Seal the board joints with Acustoseal.