Sound Insulation between joists

Barr

Hi All



We are doing an extension at the moment.

As part of this we ordered rockwool insulation – 200mm thick between the floor joists.

This is to block noise from the living room to the upstairs bedroom.

A negative seem to be it will block heat from the living room stove travelling upstairs to the bedroom.

Just weighing up the option if the rockwool is a worthwhile extra ?

Also would the extra insulation affect the wifi signal in the upstairs bedroom?



Thanks
Barr

imp1

Rockwool is a thermal insulation material, designed to stop heat travelling, e.g. from downstairs to upstairs, it has minimal effect as an acoustic insulation, though it is very very good for acoustic absorption, in the space it is in, that means there would be no echo in the floor void - should you ever want to squeeze in there. Rockwool type material is often found and used in theatre or school hall type spaces to control the echo in these spaces - though normally covered in something acoustically transparent to make it look 'nice'.
(That is also the reason you should not put rockwool below any tank in an attic - the heat rising keeps the tank from freezing)
Stopping noise travel is best and easiest done with mass - big heavy construction, though if there are any air paths due to plumbing or electrics they can be very problematic, down lighters cut in to ceilings are often a major noise path. Acoustically isolating the finished ceiling below, and vibration isolation strips on the joists overhead help a lot - getting it right at the construction or design phase is much easier and cheaper than remedial work

Barr

It sounds like it might not be useful for what I am looking for.

I was hoping it would stop noise travelling upstairs into the bedroom.

There will not be a tank directly overhead so should be OK on that front.