Noise suppresion between floors of converted flats

[ChrisD]

Hi,

I'm in the throes of converting a large victorian house into flats.

For the benefit of noise and vibration suppresion between the units I'm told that I need to install ceilings that are separate and in no way attached to the joists of the floorboards above.

My architect has suggested that I install a second set of joists positioned just below the existing ones to which I can attach the plasterboard. However this will be far more difficult than it sounds.

I recall hearing of other systems that are just as effective but far simpler to execute, can someone remind me as to what they are?

Many thanks in advance,

Chris

[BigWallop]

Sound recording studios have things called floating floors and made from carpet underlay placed under flooring grade chipboarding systems. I would have thought your architect would have heard of such systems, but then he is only an architect right enough.

The best system is made from the thick fibre felt that is used to keep plush carpets plush, and it is ideal under chipboard for sound dampening on floors in studios. The chipboard isn't screwed or nailed down, but is glued together to stop it separating. It stops sound in both directions as well.

[IMM]

Your architect is right. Use a steel frame and have Rockwool in the gap, with nothing touching the ceiling above. Use Fermacell pre-finished plaster board., It is very hard like MDF.

[Hugo Nebula]

On 17 Jan 2004 13:57:20 -0800, a particular chimpanzee named chris [e-mail] (ChrisD) randomly hit the keyboard and produced:

The conversion will need to comply with the requirements of Building Regulations anyway, and will need to be tested on completion. Have a look at Approved Document E

for the guidance.

Basically, if you don't want an independent ceiling, you have to go with a floating layer above the existing floor. This will raise your floor level by about 50mm at the very least, which may mean that you need to alter all the doors and frames, rip out all the existing skirting boards, etc. There are proprietary systems for both approaches which may limit their impact (such as British Gypsum), but the sound insulation either has to go above or below.

[The Natural Philosopher]

Airtight ceilings filled with sand.

[The Natural Philosopher]

Rockwool will do precisily nothing by teh way.

[IMM]

You obviously know nothing of such matters.

A 25kg/m3 high density mineral wool roll or rigid batt that fits properly without compression. Dedicated acoustic felts cost and arm and a leg and yet don't perform much better than good mineral wools.

[Woodspoiler]

Eh? Rockwool is sold as a noise reduction product!

isn't quite the same as the stuff that's sold for thermal insulation - same base material, different manufacture to optimise sound reduction - but even the thermal insulation product has some noise reduction effect. It won't stop noise transmitted through the structure, but it will dampen noise transmitted through air. My neighbour reported a significant reduction in traffic noise in the bedrooms when he had is loft insulation topped up to modern standards.

W.

[The Natural Philosopher]

Exactly. Both do bugger all. You need mass/ Rocvkwool hasn';t got massl.

[The Natural Philosopher]

Its margianlly effective at high frequencies, and completely useless in the lower bands. That takes mass. Or acoustic decoupling. Depending on whetherr the sound is airborne or structure borne.

[IMM]

You don't know what you are talking about. It is OK you can blame the voices.