Cavity wall injection insulation
- Thread starter David _b
- Start date
I had it done for free a few years back using expanding foam. The fitters were useless and tried to leave a meter around the top of the house unfilled. I heard them drilling the holes at the top, but not going all the way through. At first I just thought he was making marks to where he needed to drill later, but he had just filled the half drilled holes with mortar, so it looked like it had been done.
I went up after and had a look as I noticed the vents at the top hadn't been filled with silicone. I took off the vent and looked through the hole with a mirror and a torch and there was over a meter of unfilled space at the top all the way along
. Got them back and at first they were annoyed at me asking why I took the vent off 
.
So just be aware that the guys doing this sort of work might do a shoddy job to get home early as they think their work will never be seen.
I did notice a difference and have had 0 problems with mould etc. The cavity in this house is really small with it being random stone, so it will probably make a bigger difference in a house with a wider cavity. The biggest difference was when I added an extra 170mm of insulation to the loft when it was on offer for £2 a roll a good few years back.
I went up after and had a look as I noticed the vents at the top hadn't been filled with silicone. I took off the vent and looked through the hole with a mirror and a torch and there was over a meter of unfilled space at the top all the way along
. Got them back and at first they were annoyed at me asking why I took the vent off . So just be aware that the guys doing this sort of work might do a shoddy job to get home early as they think their work will never be seen.
I did notice a difference and have had 0 problems with mould etc. The cavity in this house is really small with it being random stone, so it will probably make a bigger difference in a house with a wider cavity. The biggest difference was when I added an extra 170mm of insulation to the loft when it was on offer for £2 a roll a good few years back.
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Cavity wall insulation is pretty standard simple stuff. True some houses should not be fitted with it, but most normal construction houses in normal areas (I think coastal areas and very exposed areas shouldn't be) can be.
My house was fitted with it in 1982 and everything has been fine.
Why not have a look around the area, find a house that's the same as yours, with it fitted (you can usually see if the house is rendered there are many small holes been drilled and filled in the outer walls) and ask the occupants if they have any problems.
My house was fitted with it in 1982 and everything has been fine.
Why not have a look around the area, find a house that's the same as yours, with it fitted (you can usually see if the house is rendered there are many small holes been drilled and filled in the outer walls) and ask the occupants if they have any problems.
our landlord had our house (3 bed detached) done year before last with the polystyrene balls, house is much warmer over winter now.
dont think it'll help with damp though. we run a dehumidifier anyway as its an old 1930s house prone to damp/condensation.
dont think it'll help with damp though. we run a dehumidifier anyway as its an old 1930s house prone to damp/condensation.
Soldato
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- 13 Jan 2004
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Have a word with the council - I got mine done for free through them. They might be offering some sort of efficiency thing.
Got my loft insulation for free at same time too....
Or is the £150 grant going though then council?
My house stays at 18C no problem all day and doesn't cost much. I don't have the best double glazing but simple things like shutting doors on rooms helps no end.
Regarding damp I imagine it would help in the main as it simply would help the entire house warm up.
Got my loft insulation for free at same time too....
Or is the £150 grant going though then council?
My house stays at 18C no problem all day and doesn't cost much. I don't have the best double glazing but simple things like shutting doors on rooms helps no end.
Regarding damp I imagine it would help in the main as it simply would help the entire house warm up.
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I got my loft insulation done for free on the government CSCO scheme. Could have had cavity wall insulation done too but declined that. Not just because of the possible damp issues, but because one side of the house is rendered and didn't want unsightly patched up holes everywhere.
Sorry to res this thread, it's only a month old I guess! Thought it was worth posting here as it's related. 
Me and the missus bought a new build June 2014, it's a 3-bed semi. So it's not even 2 years old yet! However... The house overall feels nice and warm, but most of upstairs feels cold! Especially our main bedroom at the front of the house often feels freezing most nights and on some mornings if the sun isn't out! The back 2nd bedroom also feels the same and the upstairs bathroom which is adjacent to our front bedroom.
However our house is entirely brick except the front top half is rendered. It got me thinking whether they have insulated all the walls properly, but reading some of your comments this might be intentional... As front top half is rendered and too much can apparently cause damp??
Any idea if it's worth asking a company to check out if it's all properly insulated (not sure how?!) or if I'm just being paranoid... Just rather know now A. To get energy bills down and B. So I can sort the insulation out now while the house is new and the developers are still in site under the NHBC warranty...
Me and the missus bought a new build June 2014, it's a 3-bed semi. So it's not even 2 years old yet! However... The house overall feels nice and warm, but most of upstairs feels cold! Especially our main bedroom at the front of the house often feels freezing most nights and on some mornings if the sun isn't out! The back 2nd bedroom also feels the same and the upstairs bathroom which is adjacent to our front bedroom.
However our house is entirely brick except the front top half is rendered. It got me thinking whether they have insulated all the walls properly, but reading some of your comments this might be intentional... As front top half is rendered and too much can apparently cause damp??
Any idea if it's worth asking a company to check out if it's all properly insulated (not sure how?!) or if I'm just being paranoid... Just rather know now A. To get energy bills down and B. So I can sort the insulation out now while the house is new and the developers are still in site under the NHBC warranty...
Put one of the power sockets off an external wall and see if you have insulated plasterboard.
Also, I had a chat with the NHBC about cavity wall insulation and they say that if you have it done and you then get damp then this could affect any claim relating to damp etc.
Also, I had a chat with the NHBC about cavity wall insulation and they say that if you have it done and you then get damp then this could affect any claim relating to damp etc.
Sorry to res this thread, it's only a month old I guess! Thought it was worth posting here as it's related.
Me and the missus bought a new build June 2014, it's a 3-bed semi. So it's not even 2 years old yet! However... The house overall feels nice and warm, but most of upstairs feels cold! Especially our main bedroom at the front of the house often feels freezing most nights and on some mornings if the sun isn't out! The back 2nd bedroom also feels the same and the upstairs bathroom which is adjacent to our front bedroom.
However our house is entirely brick except the front top half is rendered. It got me thinking whether they have insulated all the walls properly, but reading some of your comments this might be intentional... As front top half is rendered and too much can apparently cause damp??
Any idea if it's worth asking a company to check out if it's all properly insulated (not sure how?!) or if I'm just being paranoid... Just rather know now A. To get energy bills down and B. So I can sort the insulation out now while the house is new and the developers are still in site under the NHBC warranty...
Are you sure it's not an imbalance in the central heating?
Also if you have a door between downstairs and upstairs then the thermostat downstairs may switch off the heating regardless of the temperature upstairs.
Balancing the CH radiators means that the idea is that the right amount of heat is put into each room to maintain a temperature relative to the main room thermostat.
TRV radiator valves are good because you can fine tune it a little - so that once the upstairs is warm then the downstairs gets more water flow (more heating). The water will always follow the path of least resistance so you can use that to make the least resistance work for you
We've set ours up so that the upstairs is cooler, however the TRVs mean that first thing in the morning that the upstairs radiators achieve maximum flow rate - so they get nice and toasty. It means that the bedroom and the bathroom quickly go from cool to warm .. then as the shower runs, the TRV will close down the radiator there and the additional heat is then supplied elsewhere (i.e. downstairs).