R/E/P Community

R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: KB_S1 on February 08, 2010, 04:24:54 PM

Title: Cavity wall insulation
Post by: KB_S1 on February 08, 2010, 04:24:54 PM
I am putting together a studio in a fully detached bungalow.
The exterior walls are brick with a cavity to frame and plasterboard.

Although it is free standing and out in the countryside there are occasional noise issues.

I was wondering if it would help (or hinder) if I was to arrange for cavity wall insulation.
It would be the type where small holes are drilled into the exterior wall and foam insulation is pumped into the cavity.

The UK gov't is big on energy saving just now so it is subsidised and available for very little money.

Title: Re: Cavity wall insulation
Post by: Ethan Winer on February 08, 2010, 05:10:22 PM
KB_S1 wrote on Mon, 08 February 2010 16:24

The exterior walls are brick with a cavity to frame and plasterboard.


Insulation inside walls like that is always a good idea. Not only to increase isolation, but also to reduce wall resonances and get a small amount of bass trapping.

--Ethan
Title: Re: Cavity wall insulation
Post by: franman on February 11, 2010, 10:19:23 PM
Yep.. throw a nice rock wood blanket in there (100-150mm)... It's always a good thing.
Title: Re: Cavity wall insulation
Post by: J.F.Oros on February 12, 2010, 03:53:24 AM
I'm not sure the original poster has the option to put mineral wool in the cavity. He was actually asking if he can just pump expanding foam in the cavity through holes :

Quote:

It would be the type where small holes are drilled into the exterior wall and foam insulation is pumped into the cavity.
Title: Re: Cavity wall insulation
Post by: KB_S1 on February 12, 2010, 06:44:09 AM
Yes, it is a process.

We are limited with what we can do to the property. No tearing walls apart unfortunately.

My concern is that this process would effectively make the wall a single rigid leaf.
I am not sure WHAT material they use for this.

This is the purchase page> http://www.diy.com/diy/jsp/bq/nav.jsp?action=detail&fh_s econdid=9707836&fh_view_size=10&fh_eds=%3f&fh_lo cation=%2f%2fcatalog01%2fen_GB%2fcategories%3c%7b9372016%7d% 2fcategories%3c%7b9372050%7d%2fcategories%3c%7b9372232%7d&am p;fh_refview=lister&ts=1265974884456&isSearch=false

Wow, that is a big address!
Title: Re: Cavity wall insulation
Post by: johnR on February 12, 2010, 08:45:48 AM
I'd be wary of relying on expanding foam to improve isolation. It sets rigid and is probably worse than an air gap.

Normally in the UK a cavity wall is one with two layers of brick or cement blocks separated by an air gap. This would be where foam is pumped in. I suspect that if you tried to pump it in behind a plaster board wall the pressure would blow the board off.

Some cavity wall insulation is in the form of fibres or granules that are blown in. It might be worth investigating one of these.
Title: Re: Cavity wall insulation
Post by: KB_S1 on February 12, 2010, 08:51:06 AM
johnR wrote on Fri, 12 February 2010 13:45

I'd be wary of relying on expanding foam to improve isolation. It sets rigid and is probably worse than an air gap.

Normally in the UK a cavity wall is one with two layers of brick or cement blocks separated by an air gap. This would be where foam is pumped in. I suspect that if you tried to pump it in behind a plaster board wall the pressure would blow the board off.

Some cavity wall insulation is in the form of fibres or granules that are blown in. It might be worth investigating one of these.



I am not actually entirely certain of the building structure.
It is fairly modern (70s) so I would think it should be brick cavity brick walls.
Will be down tomorrow to investigate.
I am going to have to contact someone about the details of the insulation too.
Title: Re: Cavity wall insulation
Post by: Ethan Winer on February 15, 2010, 03:26:26 PM
J.F.Oros wrote on Fri, 12 February 2010 03:53

He was actually asking if he can just pump expanding foam in the cavity through holes


Yeah, good catch. There are blown-in fluffy insulations, and that's the type I had in mind. I've heard of problems with settling over time, but I don't have any direct experience so can't say for sure.

--Ethan