floor sound insulation, carpet underlay

[svouts]

Hello, I have agreed with the owner of the flat upstairs to sound insulate his floor with the condition to organise it and install it myself. The flat has a carpet floor, I would like to insulate both airborne and impact noise using a new carpet underlay.

I am going to use the most dense rubber carpet underlay I found on the market: Duralay System 10, 9.2 mm thick, density: 434 kg/m3 or 4 kg/m2.

I have some questions on how to do it.

a. Shall I remove the carpet gripers to cover all floors with the underlay, wall to wall, for better insulation and place the gripers on top of the underlay?

b. Shall I use an extra layer of damp proof membrane for extra airborne sound insulation?

c. Will it work better if I put acoustic mastic or a grub adhesive on the perimeter of the walls so as to glue the edge of the underlay to the wall?

d. Any other tips?

 

[andsally]

Hi there

I recently soundproofed one room for a musician, who wanted to reduce sound coming from the flat below.

There are several web retailers that can provide different methods of acoustic insulation and further information.

If upstairs has solid flooring then any carpet and underlay should make a big difference.

You will be able to get underlay with a higher db rating than the one you are thinking about; eg, Tredaire Dreamwalk is rated at 46db.

We realised that much accoustic leakage occured through the brick walls and joists, and any gaps. Apparentlly, were there is air leakage, there is also accoustic leakage.

Rockwall between joists will reduce transmission along the cavity between ceiling plaster and floorboards (care needed not to insulate cables). 1.5mm rubber sheet will seal gaps between floor boards. Cut to size rubber floor tiles underneath the grippers would help insulation here, where there is no underlay.

Wickes sell fibreboard underlay sheets 850 x 590 x 5mm, which could be cheap and useful.

The accoustic sealent isn't anything special in itself - the important thing is to seal air gaps.

Finally, do bare in mind that the floorboard may need to be lifted to gain access to services.

 

[svouts]

This underlay is not the best for impact noise with 32 db reduction though it is the best for airborne noise since it is the most dense, so a good choice for both impact and airborne sound insulation.

would it be possible to remove the carpet gripers, fit the underlay wall to wall, then to put the carpet gripers on top of the underlay for better airborne noise insulation?

 

[joe-90]

No. It would raise the height and wouldn't really make much difference sound-wise.

Your biggest problem is that you are listening for the noise.

 

[svouts]

I mostly listen the TV and the people talking and also walking that is why I also want airborne noise insulation

 

[joe-90]

What kind of flooring do they currently have?

 

[svouts]

it is a Victorian house conversion to flats. The floor is wooden beams with boards on top and then a cheap carpet, the ceiling underneath is just plaster board attached to the beams.

I was thinking to try first to insulate the floor with a carpet underlay and then if it is still noisy to add a second layer of ceiling with resilient bars...but I would like to avoid adding additional ceiling insulation since it low a ceiling...

 

[joe-90]

I think you are doing as much as you realistically can. By stopping the vibrations getting into the joists that should help a lot. Of all the problems in this forum noise insulation is the hardest to sort. Generally speaking, once the vibrations are into the structure you can't get them out again.

 

[UncleD]

Hi, good replies so far but a few things you need to watch out for.

First, there are two types of noise reduction: impact sound reduction and airborne noise reduction. The first is the sound of footfall on the flooring, and the second is the sound of TVs, talking and music getting through the floor.

Impact sound reduction depends upon the sponginess of the underlay, and 'andsally' is right about Dreamwalk, at 44dB (according to the manufacturer) it is one of the best underlays on the market, though Tredaire Colours Red (again based on the manufacturer's spec) is even better at 46dB.

It sounds like airborne noise reduction is your problem, so Dreamwalk would be very poor as it is not very dense; the amount of reduction of airborne noise depends upon two things, the density and thickness of the materials used, and you have already selected the best standard underlay which combines high density and thickness.

The second thing to consider is whether you need an extra layer to maximise the airborne noise reduction. You can get specialist products, such as an acoustic barrier mat, which are expensive but fantastically effective. They are basically incredibly dense layers which go underneath the normal underlay and carpet gripper. For instance, a 2mm barrier mat weighs more (5kg) than the 9.2mm of System Ten (4kg) per square metre. Because they are underneath the underlay they can be fitted right up to the edge of the wall and the carpet gripper can be fitted on top, but do use carpet gripper with nails long enough to go through the extra 2mm. If you do this it will probably mean you don't need to do anything with your ceiling.

If you fit System Ten don't put the carpet gripper on top of it. The carpet needs to stretch over the gripper, so it needs to be at the same level as the underlay. However, some sound will leak round the edges. If you've put the acoustic mat underneath which butts right up to the wall then this isn't a problem.

Alternatively, System Ten can be stuck down. You don't use carpet gripper, you use an adhesive to stick the underlay to the floor and then an adhesive to stick the carpet to the underlay. The advantage is that you can get right up to the edge to minimise sound leakage, the disadvantage is that it's a pig to lift the carpet/underlay off the floor when it is time to change it.

So, overall, my advice is a) use System Ten as planned, b) consider an acoustic barrier mat, c) don't put carpet gripper on top of the underlay, d) consider sticking the underlay down.

If you want I can recommend an online supplier for the acoustic barrier and System Ten to get them as cost effectively as possible.

 

[austincole2013]

it is a Victorian house conversion to flats. The floor is wooden beams with boards on top and then a cheap carpet, the ceiling underneath is just plaster board attached to the beams.

I was thinking to try first to insulate the floor with a carpet underlay and then if it is still noisy to add a second layer of ceiling with resilient bars...but I would like to avoid adding additional ceiling insulation since it low a ceiling...

Hi Im having this same problem ..did you get this resolved ? I have just spent 3k on barrier mats but can still here talking etc its got me beat wish i could just hand keys back