Max iso or air gap?

[bygganders]

Now we are going to insulate the floor to the upper floor but are divided about the thickness. The floor joist is 170 mm. Some say you should leave a little air to reduce impact noise. In our case, it's the opposite, we want to dampen the sound from below (impact noise downwards doesn't matter). Are we thinking correctly by filling with 170 mm, or can an air gap also help against normal sound?

Anders

 

[anaitis]

An air gap does not reduce sound at all.
Unfortunately, regular insulation, mineral wool, does not do it either.
To achieve effective sound insulation, gypsum is the best material.

 

[John J]

An air gap does not reduce sound at all. Unfortunately, regular insulation, mineral wool, does not do it either. For effective soundproofing, gypsum is the best material.

No, lead mat is better.

 

[anaitis]

Certainly, but somewhat unusual in regular villas!

 

[John J]

Granted, but somewhat unusual in typical houses!

It's not common, but I have been involved in installing it in an apartment where the owner thought it was too noisy, and the result was great.

 

[Perrka]

Cellulose-based insulation is said to have significantly better soundproofing properties than mineral wool. Check with the suppliers if it could be an option. (Warmcel, Ekofiber etc)