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SplendidStuff Posted on 02/09/2009 23:07
Sound proofing a ceiling

Have a downstairs flat with the missus and they're the old style terraced houses which have been changed into flats.

Problem i have always had in any flat like this is the noise that comes through.

The ceilings are basically their floorboards, then the joists, then our ceiling. They were id dire need of replacing and ive done part of the flat but the noise still seems to travel, when people are wlaking back and forth.

Landlord upstairs is cheap and has not put any underlay under his carpets so that dont help.

Was wondering if any builder types had any experience or knowledge on the best and cheapest way to tackle this?

I have for example in the living room put a layer of rockwool type insulation in the cavity between the joists and then put up new plasterboard.

The insulation barely makes any difference and was wondering if i just double up the plasterboard will this make much of a noise reduction. Or do i have to go and buy some specialist board that will do a better dampening job.

Any help much appreciated.

JLinardi Posted on 02/09/2009 23:15
Sound proofing a ceiling

Just make more noise than him, then you wont be able to hear their noise. OR the landlord might get sick of your noise and insulate the upstairs floor.

pedro30 Posted on 02/09/2009 23:19
Sound proofing a ceiling

Acoustic Mineral Wool is very effective followed by 2 layers of plasterboard.

SplendidStuff Posted on 02/09/2009 23:29
Sound proofing a ceiling

Just been reading up, found some info i had never come across and that is to just use joist hangars and make a suspended ceiling which wont absorb the vibrations as its fixed to the wall just below existing ceiling. This can then be insulated and boarded over and should make a massive improvement.

Bit more work like but anything for a bit of peace and quiet.

pedro30 Posted on 02/09/2009 23:32
Sound proofing a ceiling

Just install a sex swing keep the feckers up all night whilst enjoying yourself.[:D][^]

SplendidStuff Posted on 02/09/2009 23:40
Sound proofing a ceiling

Just thinking what dimension wood i will need to make a suspended ceiling.

If its going to be plasterboarded it will need to take some weight.

MY_NAMES_NOBODY Posted on 02/09/2009 23:42
Sound proofing a ceiling

I was going to recommend you inject expandind foam through your ceilling inbetween each joist them i remembered!!...

A friend of mine once built a canoe. He spent a long time on it and it was a work of art.

Almost the final phase was to fill both ends with polyurethane expanding foam.

He duly ordered the bits from Mr Glasplies (an excellent purveyor of all things fibreglass) and it arrived in two packs covered with appropriately dire warnings about expansion ratios and some very good notes on how to use it.

Unfortunately he had a degree, worse still two of them. One was in Chemistry, so the instructions got thrown away and the other in something mathematical because in a few minutes he was merrily calculating the volume of his craft to many decimal places and the guidelines got binned as well.

He propped the canoe up on one end, got a huge tin, carefully measured the calculated amounts of glop, mixed them and quickly poured the mixture in the end of the canoe (The two pack expands very rapidly).

I arrived as he was completing this and I looked in to see the end chamber over half full of something Cawdors Witches would have been proud of. Two thing occurred to me, one was the label which said in big letters: "Caution expansion ration 50:1" (or something similar) and the other that the now empty tins said "approximately enough for 20 small craft"

Any comment was drowned out by a sea of yellow brown foam suddenly pouring out of the middle of the canoe and the end of the canoe bursting open. My friend screamed and leapt at his pride and joy which was knocked to the ground as he started trying to bale handfuls of this stuff out with his hands.

Knocking the craft over allowed the still liquid and not yet fully expanded foam to flow to the other end of the canoe where it expanded and shattered that end as well.

A few seconds later and we had a canoe with two exploded ends, a mountain of solid foam about 4ft high growing out of the middle, and a chemist firmly embedded up to his armpits in it.

At this stage he discovered the reaction was exothermic and his hands and arms were getting very hot indeed. Running about in small circles in a confined space while glued to the remains of a fairly large canoe proved ineffective so he resorted to screaming a bit instead.

Fortunately a Kukri was to hand so I attacked the foam around his hands with some enthusiasm. The process was hindered by the noise he was making and the fact he was trying to escape while still attached to the canoe.

Eventually I managed to hack out a lump of foam still including most of his arms and hands. Unfortunately my tears of laughter were not helping as they accelerated the foam setting.

Seeking medical help was obviously out of the question, the embarrassment of having to explain his occupation (Chief Research Chemist at a major petrochemical organisation) would simply never have been lived down. Several hours and much acrimony later we had removed sufficient foam (and much hair) to allow him to move again. However he still looked something like a failed audition for Quasimodo with red burns on his arms and expanded blobs of foam sticking everywhere. My comment that the scalding simple made the hairs the foam was sticking to come out easier was not met with the enthusiasm I felt it deserved.

I forgot to add that in retrospect rather unwisely he had set out to do this deed in the hallway of his house (the only place he later explained with sufficient headroom for the canoe achieved by poking it up the stairwell.

Having extricated him we now were faced with the problem of a canoe construction kit embedded in a still gurgling block of foam which was now irrevocably bonded to the hall and stairs carpet as well as several banister rails and quite a lot of wallpaper.

At this point his wife and her mother came back from shopping......

Oh yes and he had been wearing the pullover Mum in law had knitted him for his birthday the week before.

On seconed thoughts, seens as its you SP...go on, i dare ya!![:P][:D]

SplendidStuff Posted on 02/09/2009 23:55
Sound proofing a ceiling

Nice story.

SO what dimesion of battening will i need to run across a room length of 4 metres?

swordtrombonefish Posted on 02/09/2009 23:55
Sound proofing a ceiling


Towell Posted on 02/09/2009 23:58
Sound proofing a ceiling

If you're hanging a suspended ceiling you could just hang peices of angle from the existing joists and then thread the wire to hang the ceiling off that.

You'll lose some head room like, then you can just put some acoustic tiles in the grid and it might do the job, the problems come in getting the grid level, ideally you need a laser.

EDIT: Didn't read properly sorry I was thinking you were on about hanging the type of suspended ceiling that you get in hospitals, schools etc.

SplendidStuff Posted on 03/09/2009 00:15
Sound proofing a ceiling

Got a laser, bought it 2 years ago, finally a use for it[smi]

Going to use 4000 x 100 x 50 timber beams and attach to wall using joist hangars. This way new ceiling is insulated using 100mm of rockwool in the cavity and is not attached to the exisitng ceiling, so no more vibrations[:D]

Can't wait to get cracking on this one, anyone know if wickes or b&q take ages to deliver?

Towell Posted on 03/09/2009 00:16
Sound proofing a ceiling

So you're going to hang joists off the existing joists and then plasterboard onto that?

SplendidStuff Posted on 03/09/2009 00:20
Sound proofing a ceiling

No the new joists are going to be ran from wall to wall using joist hangars, they screw to the wall as opposed to ceiling and the joists sit in them and run across the room.

This is the best way as the ceiling will be independant and not have any contact with the old ceiling so no vibrations and a large enough cavity or vacuum that i can pack tons of rockwool into.

MY_NAMES_NOBODY Posted on 03/09/2009 00:20
Sound proofing a ceiling

I dont think rock wool will do much good as a sound proofer.

Towell Posted on 03/09/2009 00:24
Sound proofing a ceiling

Ah right yer sorry I was thinking of the more convetional suspended ceiling.

So them joist hangers come off the masonry walls?
Should be OK but you'll probably fuq up any existing stud?

MY_NAMES_NOBODY Posted on 03/09/2009 00:28
Sound proofing a ceiling

would'nt it be easier if you just went upstairs and explained the situation to them and offer to py for some thick underlay to be fitted?..would'nt cost that much and would be a lot cheaper and easier that hanging a new ceilling, and if its still noisey you can allways go ahead and hang it at a later date, and with the underlay upstairs already down, it'll make it a lot quieter.

SplendidStuff Posted on 03/09/2009 00:38
Sound proofing a ceiling

No i need a new hobby[:D]

Besides i would prefer a permanent solution, especially as upstairs is rented so no telling who will move in.

Towell the existing stud frame is not used, like i say joist hangars are just screwed to the walls.

SplendidStuff Posted on 03/09/2009 00:41
Sound proofing a ceiling

And 100mm of rockwool or more in the cavity between the 2 ceilings will be more than adequate.

Towell Posted on 03/09/2009 00:45
Sound proofing a ceiling

100mm is XXXXXXloads to be fair, don't think you'd hear anything, just so long as it's packed right to the edges.
Good luck!

SplendidStuff Posted on 03/09/2009 00:45
Sound proofing a ceiling

My ceilings are like 12 ft high[cr]

And i have 6 rooms to do[cr]

guyham Posted on 03/09/2009 05:10
Sound proofing a ceiling

It's a bit more complicated than what's been said above mate.

Firstly, the sound you're probably bothered by is the sound of the people moving about upstairs - foot steps and the like. That's impact sound, not airbourne sound.

If you screw or nail a batten into the joists then nail or screw a plasterboard to that, the sound will still travel through the fixings. You need an airtight sandwich of dense and soft layers with an airgap mate. It's hard to achieve in old houses.

Fix an acoustic hanger (you can buy these from drywall merchants, or make them with angle cleats and a thick rubber washer) and hang galvanised angle from those. a British Gypsum "MF" ceiling with two layers of soundbloc plasterboard should do, with an over layer of 50 acoustic partition roll. None of this is fastened tight to the existing ceiling - meaning that there is an airgap in there too. Seal around all the perimeter with acoustic mastic before plastering.

Sound will get through whereever it can. It may be coming down the chimney too.

Good luck. Not an easy job!

UnreelOneel Posted on 03/09/2009 05:55
Sound proofing a ceiling


probably just repeating what he said, but with North American designations. It's not that hard.

Whatever equivalent to fire-rated drywall you have.. use it. 5/8 type X, will kill sound (and fire, 45 minutes per layer).

Don't fasten the board to the joists, strap em with resilient channel 16 inches on centre. Cheap, quick, easy.

Resilient Channel: