Loft roof insulation and noise prevention (expanding foam)

[Delfi]

Hi,

I live on a busy main road and am waging war on the noise. Last night I had a glazier round to discuss options about sound proofing the windows and he made good mention to sound also permeating through the walls.

Below is a picture of our bedroom - which is not in a loft conversion per say, but in an old dormer thing on the roof. It's noisey (has relatively good condition retro fitted double glazing) and may soon have secondary glazing.

Untitled

• Delfi
• 27 Jan 2015
• 1

However, the room is also a bit cold.... which got me thinking - since this a fairly old structure - it's probably relatively poorly insulated.

Is it possible, and are there any reputable firms out there that could come and inject expanding foam into the cavities under the roof eaves, and to the sides of the dormer that you see in the picture. I assume the sides are brick - but they certainly sound hollow to a tap - so there must be a plasterboard inner finish.

I've read some reports that you need air to allow the joists to breathe - are there any solutions out there that anyone has heard of?

Thanks.

 

[geraldthehamster]

You don't want to inject any sort of expanding foam that will prevent the rafters from breathing - as you correctly suspect, this will most likely cause rot.

Neither will expanding foam, or board insulation like Celotex, be very effective as sound insulation. A combination of acoustic mineral wool insulation batts, and sound block plasterboard, would have some effect.

Cheers
Richard

 

[Delfi]

Just trying to avoid tearing down all of the wall coverings - at first had the great idea of a few 10mm drill holes and some injection foam....but that seems to not be a good plan....

 

[freddiemercurystwin]

Soundproofing is a funny 'ol game but avoid any expanded foam idea.

 

[geraldthehamster]

Just trying to avoid tearing down all of the wall coverings - at first had the great idea of a few 10mm drill holes and some injection foam....but that seems to not be a good plan....

I've made the mistake in the past of trying to a job with the minimum of intervention to the existing. You're usually better off ripping out so you can do a proper job.

Cheers
Richard