Cavity Wall Insulation in new homes

Middlers

I recently moved into a newbuild property and the insulation used is similar to a space blanket wrapped around the block work. I am thoroughly unimpressed with its thermal properties and have to have the heating set at 24 degrees just to keep warm Having had cavity wall insulation in a previous property I asked a firm to give me a quote but was disappointed when the 'surveyor' informed me that you cannot mix two insulators as they could react together. I find this very odd and wondered if anyone had heard similar or if there was an 'expert' on the forum who could give their opinion please? Thank you.

NeverInDebt

surely if its new property it must meet certain standards like insulation, perhaps they didnt do a very good job which begs the question what else have then done wrong?

Middlers

NeverInDebt wrote: »

surely if its new property it must meet certain standards like insulation, perhaps they didnt do a very good job which begs the question what else have then done wrong?

Oh, there are plenty of things wrong but heating is the priority at the moment.

brig001

I would talk to your neighbours (assuming built by same builder) and see if they have same problem. Then talk to the builders - if everyone complains, you might get somewhere. If not, I would try building control to see if they can put pressure on the builders. One thing for certain, don't let it lie, otherwise you will be paying higher bills for the rest of your time there.
HTH, Brian.

LisaLou1982

Hi,

Im an insulation and PV surveyor and what you have been told is correct. You cant mix 2 different types of insulation. If your wall already has cavity wall insulation then you cant add to it.

However, there are cases whereby the CWI is within the "insulating" block and the cavity between it and then brick is empty. If this is the case then you can fill that cavity with CWI but id have assumed that the person you had round has already drilled the wall and scoped and checked the gap.

Thanks

Lisa

Rikki

LisaLou1982 wrote: »

Hi,

Im an insulation and PV surveyor and what you have been told is correct. You cant mix 2 different types of insulation. If your wall already has cavity wall insulation then you cant add to it.

However, there are cases whereby the CWI is within the "insulating" block and the cavity between it and then brick is empty. If this is the case then you can fill that cavity with CWI but id have assumed that the person you had round has already drilled the wall and scoped and checked the gap.

Thanks

Lisa

I had my twenty four year old house checked about eight years ago and was told I have CWI being the blocks when built.
In the past two years three neighbours have paid to have CWI. I'm confused can this deteriorate over the years or are the just adding to the existing CWI?

LisaLou1982

Rikki wrote: »

I had my twenty four year old house checked about eight years ago and was told I have CWI being the blocks when built.
In the past two years three neighbours have paid to have CWI. I'm confused can this deteriorate over the years or are the just adding to the existing CWI?

More than likely theyre adding to the existing:

A few reasons for this:

Guidelines between companies and CIGA change all the time. At one point we couldnt insulate anything that had thermal blocks in regardless of whether there was a cavity gap. Now we can.

Did the surveyor drill and scope your wall? If there is a polystyrene sheet on the outside of the block, facing the brick, then you wont be able to have the gap filled as this would involve mixing materials

If you and your neighbours have the poly block sheet and theyve had theirs done regardless then they wont be protected by CIGA should anything go wrong and i would strongly advise that you dont get it done

If theres no poly sheeting (just thermal block) then its fine to get insulated.

Rikki

LisaLou1982 wrote: »

More than likely theyre adding to the existing:

A few reasons for this:

Guidelines between companies and CIGA change all the time. At one point we couldnt insulate anything that had thermal blocks in regardless of whether there was a cavity gap. Now we can.

Did the surveyor drill and scope your wall? If there is a polystyrene sheet on the outside of the block, facing the brick, then you wont be able to have the gap filled as this would involve mixing materials

If theres no poly sheeting (just thermal block) then its fine to get insulated.

It was so long ago I'm a little unsure of what he said exactly. He did drill into the brick work but I can't remember him doing anything else ie: scope? It was you have cavity insulation your fine.

LisaLou1982

If hes done the drill test and told you its fine then it probably is.

Wont hurt to ask a company out to check though if youre still unsure.

daveyjp

If you have to have heating set to 24 degrees and you are still cold, the central heating system or the property has a problem. I'd start with the heating.

brig001

Just a thought, are your walls dot and dab? Plasterboard on top of leaky blockwork walls could easily cause the problem you describe. Clues could be draughts from sockets, light switches and under skirting boards.
HTH, Brian.