Cavity wall insulation .

Or indeed is it actually safe? i.e is the cavity maybe there for a reason? Often wondered this.
 
DorsetDude said:
Or indeed is it actually safe? i.e is the cavity maybe there for a reason? Often wondered this.
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Yes it's safe. The cavity is there primarily to stop moisture penetrating. Most, if not all, new buildings have insulation already in the cavity. After market installed insulation is usually in the form of resin beads, these won't form a bridge to allow moisture to transfer.
 
PaulButler said:
Yes it's safe. The cavity is there primarily to stop moisture penetrating. Most, if not all, new buildings have insulation already in the cavity. After market installed insulation is usually in the form of resin beads, these won't form a bridge to allow moisture to transfer.
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And is it effective even on exposed walls and what have you?

Is the blown foam stuff/feathery type not used anymore?
 
Yes, effective on any cavity wall. Polyurethane foam is still used in cavities.
 
Either are fine. Probably easier to "fit" the beads as the polyurethane is two chemicals mixed and then injected. If you are paying someone to do it may be worth checking they are registered with these people http://www.ciga.co.uk/
 
I had the foam type injected many years ago,
and the difference was noticeable almost from the off.

I'm still in the same house many years later,
and have not noted a down side.

When the side extension was built, the guys used huge slabs of polystyrene
type to fill the cavity as they were bricking up.

Well worth it IMO
 
Thanks guys. I know it is wide open question, but sort of figures are we talking and how long does it take to install?
 
FlyTVR said:
Thanks guys. I know it is wide open question, but sort of figures are we talking and how long does it take to install?
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Mine was about £200 IIRC but it was a fair few ago, as I said :D
Also IIRC they were here pretty much a full day.
 
Took just under a day to fit ours and it has made a bit of a difference. Not as much as the loft has though. There are some houses where cavity wall insulation is not appropriate.
 
Had cavity wall insulation done a few years ago and the loft insulation was upgraded at the same time, can't put an exact £££ on savings but the house is much warmer and bills have been reduced ... cost around £100 under some government/gas company scheme when it was done.
 
munch said:
Took just under a day to fit ours and it has made a bit of a difference. Not as much as the loft has though. There are some houses where cavity wall insulation is not appropriate.
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It is getting to the bottom of this that I can never find an answer to. And I wouldnt expect a cavity wall installer to give me an unbiased answer so kind of leaves you in the lurch.
 
Is my house regularly exposed to wind driven rain? Hmmm, only when its windy and raining. Er... :thinking:
 
I had those resin bean things in the walls of a flat and when the hurricane hit in the 80s we had a loft full of them, wonder what t was at first.
In my last house, we had it put in under a grant, and yes it was noticably different, much warmer
 
I'm doing major works on a bungalow I have just bought. As I'm working my way through, some of the external walls have been removed to make way for an extension. There were obvious signs of cavity insulation being done, due to the holes in the walls where it was pumped in. Upon removing the walls it was noticed that the pumped insulation was not pumped in anywhere near enough. There were a lot of big pockets of absolutely nothing. Previous to buying this property, i paid for cavity insulation to be installed where I was living. Going on what I have found recently I can't be sure it was done properly, as I didn't notice any difference in general warmth. Would I pay for it again? NO. Would I trust any of these insulation companies again? NO. I personally do not think it is worth it.
But that is only my opinion.
 
dekeyboy said:
. Upon removing the walls it was noticed that the pumped insulation was not pumped in anywhere near enough. There were a lot of big pockets of absolutely nothing.
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Obviously there are different "grades" of workman,
I guess that one was a friday afternoon job ;)

When they did mine they drilled "all over" in the morter junctions,
starting at the bottom, they put small "sticks" in the holes above.
They didn't move up until the "sticks" were pushed out of the holes.
And repeat.
They even checked in the loft to make sure it was visible in the gable ends.
 
Cobra said:
Obviously there are different "grades" of workman,
I guess that one was a friday afternoon job ;)

When they did mine they drilled "all over" in the morter junctions,
starting at the bottom, they put small "sticks" in the holes above.
They didn't move up until the "sticks" were pushed out of the holes.
And repeat.
They even checked in the loft to make sure it was visible in the gable ends.
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You must have had some conscientious workmen, and I'm glad yours was successful. We were told it would take about 4 hours to do. I was at work and my wife had to go out whilst the work was done. When she returned the men had left a note to say they had finished. Admittedly they had tidied up behind themselves. According to a friendly neighbour the total time was around 2 3/4 hours.
When I questioned it with the company concerned, they told me that the team of men could be trusted to do a thorough job. I am in the building game but went through the part grant option. I feel I was too trusting and maybe got caught.
 
dekeyboy said:
I feel I was too trusting and maybe got caught.
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Thats no excuse though is it?
they should do a good job whatever.

I note you said bungalow, my place is what they call a chalet style,
so probably very little difference in actual wall brick cavities,
the majority of the "upstairs" is tile faced with pasteboard inner and rockwool (type) filling the cavity.
The point is it still took them best part of a day to complete.

I guess you were just unlucky :(
 
Gremlin said:
I had those resin bean things in the walls of a flat and when the hurricane hit in the 80s we had a loft full of them, wonder what t was at first.
In my last house, we had it put in under a grant, and yes it was noticably different, much warmer
Click to expand...

Some years ago, my parents had the polystyrene ball type of CWI pumped in and like Ingrid, they started finding loads (and I mean LOADS!) of the balls everywhere and this was during the summer. Turns out that the workmen hadn't turned the tap on to add the adhesive to bind the balls together to stop them leaking out since they had found that doing the job properly and adding the glue caused blockages meaning they couldn't do as many jobs per week. Not sure if it was ever discovered if this was company policy or just a couple of rogue installers but I have come across several other properties that were done at about the same time and which have loads of balls in the garden. Mum and Dad got the firm back to pump out the remaining few balls, a full refund and injected PU foam by another company.
 
Nod said:
. Not sure if it was ever discovered if this was company policy or just a couple of rogue installers but I have come across several other properties that were done at about the same time and which have loads of balls in the garden.
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Actually now you mention that,
it reminds me, when we were looking at cavity wall insulation,
we were advised by a few people, not least the company that did ours, (they offered both types)
to avoid the "balls" as the go everywhere.
So it seems it may have been quite common practice ;)
 
Yep especially as sometime later after we moved the landlord decided to install double glazing, you can imagine what happened when
they removed the first window in an upstairs flat :D
 
I shouldn't laugh at that, Ingrid - but I did!

Interestingly, I've been out with my FLIR camera which shows heat loss and relative temperatures of surfaces and our house (no CWI) shows the same exterior wall temperature as next door (with CWI).
 
I had the polystyrene ball type put in just over a year ago, it made a noticeable difference last winter, the house definitely warmed up faster and cooled down slower.

They did use the adhesive - a colleague has a 25 year old house which has the same insulation installed but without the adhesive. When they had the fireplace for a gas fire moved, a few binbags worth of polystyrene balls flooded out into their lounge :D (as I warned him might happen :p )
 
Gremlin said:
Yep especially as sometime later after we moved the landlord decided to install double glazing, you can imagine what happened when
they removed the first window in an upstairs flat :D
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Almost as funny as the eejits that drilled a single brick wall and filled the lounge with insulation before realising their mistake.
 
Had ours done a few years ago, and have never regretted it. The house stays cooler in the summer, and warmer in the winter.

The first thing we noticed was that the central heating boiler fired up less frequently, that is to say that it spent longer in the 'off' state than the 'on' state, when running.

The house, which is a 'largish' four bedroom property, quite detached, backing onto open farm land, so quite exposed, has been a good test.

22mm spaced double glazing, a well insulated loft, and cavity wall insulation, has made the house more comfortable in summer and winter, and cut the heating bill.

So, is cavity wall insulation worth it?. IMO absolutely!!.

BTW, our house was done with 'Blown Rockwool'.

Dave
 
had mine done for free,

I noticed a huge difference, when were were able to close the door from upstairs.

now we have cats, and every door has to be left open, and upstairs we have crittall windows with no secondary glazing (conservation area) and has rendered the insulation pointless lol
 
Ours was also done for free - the Mark Group..
Night & day difference -heating only got turned on for the first time on the 29th of Nov..(other than periodic testing) & now have to keep turning the TRV's down in the front room...
Get it done - it may not even cost you anything...
 
Insult-ulation_zps22c020d0.jpg~original
 
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