Improving soundproofing of a ceiling between two flats

[andrewpreece]

You more-or-less have the right idea. The only cures are mass ( reflects sound ) and absorption. Plasterboard will give you mass, rockwool or similar will give absorption as well. The idea suggested of two layers of plasterboard seems good as well, with absorbing rockwool between. One thing, avoid gaps, sound will disproportionately squeeze through gaps, so you need to find a way to seal the plasterboard around the edges of the room. The thing is, if you fix the plasterboard rigidly to the vertical walls, some sound waves will couple with that way too. Beware of fixing the plasterboard rigidly to any ceiling supports either, as some similar coupling will also occur. Perhaps you could resiliently couple the plaster board to anchors in the ceiling somehow, i.e. rubber loops, or maybe have the anchors/brackets poke through the plasterboard, so a resilient mount could support the plasterboard from underneath. Sorry if this is not the practical advice you're after, but I hear that poorly designed sound attenuation systems produce poor results so it's the little details you have to look out for.

Andy.

[McB]

I live in a flat and there is another flat immediately above mine. It's a converted house. I'd like to improve the sound insulation between the flats by modifying the ceiling which hasn't been modified sice the house was built some 100 years ago. Does anyone know the method specified by current building regulations? Or, if they are impractical or prohibitively expensibve, the method specified by yesteryear's buibuillding regs?

Without knowing the building regs, my own inclination would be to use one of the two following methods:

1) Cover the ceiling in 12" plasterboard, fixed by screwing up into the existing joists.

OR

2) Probably better but more difficult and expensive: Construct a new ceiling, fixed only at the walls and not touching the existing ceiling, using angle iron and 4"x2" timber, with 12mm plasterboard, and glass wool in-between it and the existing ceiling.

Thanks

McB

[Dave Plowman (News)]

The more 'solid' the false ceiling, the better it will work. Consider using two layers of plasterboard. It should also be decoupled from the existing one as much as possible to help prevent structure born noise.

[Owain]

"McB" wrote | I live in a flat and there is another flat immediately above mine. | It's a converted house. I'd like to improve the sound insulation | between the flats by modifying the ceiling which hasn't been modified | sice the house was built some 100 years ago. Does anyone know the | method specified by current building regulations? Or, if they are | impractical or prohibitively expensibve, the method specified by | yesteryear's buibuillding regs?

In days of old in purpose built tenements, fine gravel or clinker was used in the void. But that is heavy and the floor joists need to be sized accordingly. Yours probably aren't.

If it is footstep noise then the best plan of attack is from the floor above. Resilient interlayer and then new chipboard surface floor, then thick underlay and carpet.

Owain

[Steve Firth]

The traditional method is pugging, laying boards between the joists and covering the boards with a layer of sand.

[McBain99]

Thanks to everyone for the replies so far. However, I stress that I'm only inteested in what I can do to the ceiling, since I don't have access to the flat above. I'm particularly interested to know what building regs (past and present) have recommended in the way of ceiling mods.

McB

[IMM]

No. Two layers of platerboard with staggered joins and dense rockwool slabs not fibreglass.

That is very heavy.

[McB]

Thanks for the tip. Do you happen to know if that would comply with building regs for a ceiling beneath another flat?

Also impractical, because I don;t have access to the floor above!

Thanks again

McB

[Hugo Nebula]

On Sun, 21 Nov 2004 11:17:52 GMT, a particular chimpanzee named [e-mail] (McB) randomly hit the keyboard and produced:

page 56.