I’ve always been put off getting cavity wall insulation as when it first got fitted retrospectively I heard lots of horror stories of damp getting in and mould growing in houses. That was quite a few years ago so I wondered if it’s worth it. I live in a sub-urban 3 bed link-detached (attached at the garage to next doors living room) in the midlands so I don’t think it’s an issue for driving rain, lack of shelter etc.

Also, we have a conservatory on the side and some PVC cladding to the front elevation. Are they able to install the insulation behind these or will those areas be missing the insulation?

Any advice gratefully received.

Quick Google of Link-detached threw up this house which is similar apart from we have pvc cladding between ground and first floor windows. Disclaimer: This is not our house and I have no idea whose it it.

Our 1920’s house has it, (bought it with it didn’t choose) was initial a bit worried but haven’t had any issues over the past 15 months of living here. Have since changed windows and loft insulation, the loft insulation seems to have made the most difference so would have that done first if I was you.

Our 1920’s house has it, (bought it with it didn’t choose) was initial a bit worried but haven’t had any issues over the past 15 months of living here. Have since changed windows and loft insulation, the loft insulation seems to have made the most difference so would have that done first if I was you.

Our insulation is already up to 270mm so not much point putting more in there.

This image suggests that more heat is lost through the walls than through the roof. Strange as I thought heat rises and therefore the roof would be the worst, but apparently not.

Loft insulation first then dry-line the exterior walls, which allows you to re-decorate from new and move elecric sockets etc.

silver bonded bead cavity wall insulation avoids issues with damp spots etc

big_n_daft – Member
silver bonded bead cavity wall insulation avoids issues with damp spots etc

Thank you for that information. If it’s loose beads does that mean that they will fall down the cavity too and so fill in gaps behind the conservatory and cladding?

I had it done as part of a government scheme where it was free a few years ago. I must say I’ve not noticed much different other than the house stays quite cold in the summer. It’s hard to assess its economical benefits because the bills keep getting increased anyway but if you can get it for free I would if only because it is a good tick to have in the box when selling if you ever do.

I think in terms of feeling the benefit other measures have been more noticeable. For instance we have Karndean laminate flooring throughout the ground floor and since insulating under the floor I don’t know if the house is kept much warmer but not having cold feet certainly makes it feel that way.

In terms of your conservatory they may be able to get the beads to fall all the way down the cavity but when they did mine they required the injection holes to be a certain maximum distance apart so not sure.

We had it done last year as part of the government scheme. We chose British gas to install it because hopefully if anything went wrong then there would be some comeback instead of a random company who could disappear into the night.
We were amazed how much difference it made. The house used to cool down pretty quickly when the heating went off but now holds its heat a lot better and warms up much quicker.
The directly employed workers from British Gas did a very neat and tidy job. You honestly wouldn’t of known they had been. All you can see is a diamond grid pattern of filled holes with new mortar if you look closely to the external walls.

My house is almost identical, never had a single problem since it was done 10 years ago, neither has anyone I know.(all glass fibre) The problems according to government studies are quite rare.

The only area it couldn’t do is behind the PVC, as on mine its done by pushing the brick back against the block.

No problems with ours. House is a little cooler in the summer & warmer in the winter. The insulation beads had some sort of glue on them to stop them moving about (apparently).

ours is loose bead and on the rear elevation it got damp on the south facing walls (disclamer – its really bloody exposed on top of a hill facing the sea)

its also a basterd when you want to do anything as the little balls go bloody everywhere.

since had teh house externally rendered and they did it using external insulation (mainly to prevent water ingress on the rear) and also when they re-did the windows on the rear most of the balls fell out.

After much reading, and some direct experience of soggy glass fibre cavity wall inaulation through work, I went with graphite impregnated poly beads the ‘silver poly beads’ as mentioned above. They’re held together with a slight dusting of PVA.

The heating in my place is thermo statically controlled, so ita difficult to say, but I reckon the heating kicks in less frequently, for less time.

I’d not touch glass fibre.

made a positive difference to ours, we had the beads done and it was fine

Don’t get me started on frikkin cavity wall insulation 😈

Research how a cavity works, porosity of bricks and the affect of zero ventilation in an enclosed space.

Then decide for yourself. My guess is that you’ll opt for the suggestions above concerning foil lined insulated plasterboard…

I’m beginning to feel like a broken record 🙄

My advice would be don’t do it, any of it, we had it done by weathershield on my last house, we got damp patches on the rear wall which I put down to them doing a crap job, I replaced some of the inside window cills later and the insulation was extremely patchy to say the least

and the b******s wrecked my lean too conservatory, I was promised they’d put scaffolding up, as i was at work all day I had no idea they’d put boards on it I was horrified when a neighbour told me and it took my ages to sort the leak

Of course I complained, had various people down and got nothing more than annoyed

Research how a cavity works, porosity of bricks and the affect of zero ventilation in an enclosed space.

hence recommending the beads. They flow in to the cavity and don’t stop it doing what it is supposed to

I’ve not read how a cavity supposidly works but houses built these days have polystyrene boards placed inside the cavity taking up all the void. This was done to my Extension build last year also.

I had the white fluffy stuff put in a few years ago. I noticed an improvement – not night and day, but a slight but noticeable improvement. my home is a mid 90’s build detached house, standard brick and tile construction. The downstairs has always been noticeably cooler than the upstairs – quite cold on a sub zero day, but post cavity wall insulation there was a noticeable improvement in the downstairs temperature – On a cold morning it is now noticeably warmer instead of just taking the chill off. Not noticed any issues with damp yet.

The longevity of the fluffy insulation has yet to be proven, in my mind it will settle over time so I imagine i’ll have dense collection of the stuff in the bottom half of the cavity and nothing in the top, but that’s a problem for another time, it might need topping up or something.

My dad had some stuff put in his home back in the mid ’80’s. Not sure what it was but it was pumped in like the fluffy stuff. He’s had absolutely no problems at all in the 30 or so years since having it done. Definitely no damp.

No real idea what we had put in 5 years ago, it looked like shredded paper (but probably wasn’t) but along with new windows It’s made a massive difference.

No damp either.

We have 2 neighbours with it. Both want it out as they now have damp problems. 1915 built houses though.

We have the silver beeds as the cavity is two narrow for other forms . The house was poorly built in the 30s . The insulation has made a massive difference. We have a couple of damp spots but they clearly have other causes . since installation the house has been warmer and dryer . just need to refix the flat roof and dig through the strata of patios that bridge what remains of the dpc.