Cavity wall insulation

bainbridge

bainbridge

bainbridge

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We bought our house a year ago, it was built in 1989.

A man has just knocked in the door offering grant funded cavity wall insulation under the government HHCRO flex scheme.

What effects might thermal bead insulation have with regards to damp?

I trained as a bricklayer many years ago and it was drummed into me NOT to bridge the cavity. Any cavity insulation batts had to be held against the inner wall with tie clips, all wall ties needed a drip and we took great care not to fill the cavity above the damp course.

I accept technology and materials have moved on in the 25 years since I was building houses, but bridging the cavity just doesn't sit well with me. Won't those little beads provide a perfect path for penetrating damp via capillary attraction? And won't filling up the cavity above dpc provide a path for rising damp?

I'm confused.
 
I've read a lot of horror stories, but we had it done on a ~1908 terraced house and had no issues whatsoever.

As a note however, we moved in in 2010, had it done ~2012 and moved in 2018, but i'd have thought any issues would've appeared by then if they were going to.
 
The horror stories I came across seem to be around the house no longer being able to "breathe" properly leading to condensation issues - rather than capillary action within the insulating material. Once the stuff is in, its a complete pain to remove.

I looked at this a while ago for my house (1997 build) when the energy companies were all pushing it to meet their eco targets. The deciding "no" for me was that the holes they'd have to drill were wider than the mortar gaps, so my house would have ended up looking like a zit laden teenager as they'd be knackering loads of the bricks.

I'd also be sceptical of someone knocking on the door claiming there's grants available. I'd bet there's all sorts of hoops to jump through and some sort of means test to get it, even if it does exist.
 
There are grants available, we had someone come over (registered business) to look into free loft insulation, who mentioned that we'd almost certainly qualify for free cavity wall insulation too. Horror stories scared us off though (just read another in the community page on facebook too).
 
As a surveyor I will tell you to avoid it.

do you freeze in winter? No.

your house if rendered will end up with horrible holes all over it, you could bridge the cavity, cause cavity wall ties failure etc.

also, if the property is timber framed then run a mile as it could make it unmortgageable.
 
fastwunz said:
As a surveyor I will tell you to avoid it.

do you freeze in winter? No.

your house if rendered will end up with horrible holes all over it, you could bridge the cavity, cause cavity wall ties failure etc.

also, if the property is timber framed then run a mile as it could make it unmortgageable.
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As a surveyor, may I have a free nugget of information as to your take on external wall insulation? Is it that much better than cavity wall insulation?
 
The house I live in has had it done recently (the bead type) - the grant can take quite a long time to get approval. I'll let you know what the outcome is :s

The exterior walls are in good condition though so hopefully it will improve things.

peterwalkley said:
I'd bet there's all sorts of hoops to jump through and some sort of means test to get it, even if it does exist.
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No means testing - but I definitely wouldn't just use the first person who came knocking.
 
we had ours done a few years ago under the grant scheme rang up the council and they gave us the approved installer list , that side was pretty quick and painless.
our house is a mix of solid and cavity walls, main building cavity extention single. they only did the cavity. cant say i noticed a major difference ..EXCEPT beware we have noticed a problem with damp in the dining room which had to remedied about 6 months after. the builder said it was due to the cavity being blocked ,(maybe some rubbish dislodged not sure but 12 months on it hasnt reappeared.

on a side note the same company offered us loft insulation and when they realised we had flooring in the loft said they could lay in on top perhaps alarm bells should have rung :)
 
gc123 said:
we had ours done a few years ago under the grant scheme rang up the council and they gave us the approved installer list , that side was pretty quick and painless.
our house is a mix of solid and cavity walls, main building cavity extention single. they only did the cavity. cant say i noticed a major difference ..EXCEPT beware we have noticed a problem with damp in the dining room which had to remedied about 6 months after. the builder said it was due to the cavity being blocked ,(maybe some rubbish dislodged not sure but 12 months on it hasnt reappeared.

on a side note the same company offered us loft insulation and when they realised we had flooring in the loft said they could lay in on top perhaps alarm bells should have rung :)
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How did they remedy the damp? My house already had CWI installed and there is some plaster bubbling near the has fire and French windows. I guess it is a blocked cavity. But not sure how to sort it. Is it a case of removing bricks?
 
We did this a couple of years ago, thermabead I think they were called. Haven't noticed lower bills or the house being warmer so it so was probably not worth it, even if it was free
 
Thanks for the replies everyone. I'm going to leave it. I appreciate the thermal properties of foam balls but just don't like the thought of bridging the cavity.
 
A couple of years ago our housing association removed the old insulation from the walls and replaced it with thermal bead insulation and it's made a massive difference, not all good though. In the winter the house holds the heat much better and has dropped our heating bills by quite a bit. In the summer though it can be a nightmare as it's very hard to cool the house. During the recent hot spell the temps indoors ranged from 24.2-26.7 degrees C and that was with all of the windows open, it was cooler outside.
 
pastymuncher said:
A couple of years ago our housing association removed the old insulation from the walls and replaced it with thermal bead insulation and it's made a massive difference, not all good though. In the winter the house holds the heat much better and has dropped our heating bills by quite a bit. In the summer though it can be a nightmare as it's very hard to cool the house. During the recent hot spell the temps indoors ranged from 24.2-26.7 degrees C and that was with all of the windows open, it was cooler outside.
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We're all electric and last winter was pricey for heating. It's interesting how you've had increased summer temps because the supplier's leaflet says it keeps the house cooler in summer. Obviously it's their sales pitch. It's damp that I'm most concerned about, have you had any issues with damp since getting it done?
 
TheFew said:
How did they remedy the damp? My house already had CWI installed and there is some plaster bubbling near the has fire and French windows. I guess it is a blocked cavity. But not sure how to sort it. Is it a case of removing bricks?
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The whole cavity will be blocked when they fill it with thermal beads. I guess if you were to remove bricks in the affected area and remove thermal beads, more would come tumbling down like a big game of Ker plunk (One for the fellow oldies there).
 
We haven't had any issues with damp so far. If I remember right they add some sort of adhesive to the beads when they inject it into the wall. I still find some in my garden every now and then because they made a hell of a mess.
 
Tom_ed1987 said:
Are you sure your house doesn't already have insulation from new? I think mine was built in late 80s & does.
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Yes I've been meaning to check. There's a couple of holes already there from old cable TV wires i snipped, been meaning to pull out the wires and fill the holes so I could do a quick check with a mobile phone borescope
 
pastymuncher said:
We haven't had any issues with damp so far. If I remember right they add some sort of adhesive to the beads when they inject it into the wall. I still find some in my garden every now and then because they made a hell of a mess.
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Glad to hear you've not had damp. That's interesting about the adhesive and would explain why they have to drill all over the place rather than tipping them in from high on the first floor.
 
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