Cavity wall insulation?

[Lagoonablue]

Am I mad or is there a reason I can't have it on my 1930s semi? Did I read it wouldn't work on such a house?

I have. British Gas coming to do a survey for it. It could cost me nothing they say. Is this right? Seems to good to be true.

My house is cold.....Poor DS aged 4 has the coldest room and the cold seems to seep on from the wall.

Any advice?

[bilbodog]

houses with cavity walls only started being built after WWII so anything 1930s or older wont have a cavity - you will probably have a solid brick wall so there is no cavity to fill. Also be wary of adding any insulation to walls either outside or inside as these houses were meant to 'breathe' through the walls so if you line them with something you will just make the house sweat inside which will cause lots of damp and condensation. You need to make sure your roof is well insulated. If you have original windows and doors get them draft proofed and have heavy lined curtains to cut out the cold. And get the kids to put on a jumper........... or turn the heating up - which very you can most afford!

[MuscatBouschet]

Not true. Plenty of 1930s houses have cavities. Ours are insulated and we generally don't have a condensation problem, but many do so beware and read widely before you go for it. Maybe talk to neighbours with similar houses too...

[wowfudge]

Sorry bilbodog, but that's just not true. Our house was built in 1931 and has cavities and British Gas's free cavity wall insulation! It is older houses which tend not to have cavity walls.

When the surveyor comes round OP, he will drill a pilot hole or two to assess whether there is a cavity and whether it is sufficiently wide to take the insulation.

Be aware that if you have any issues with damp on your external walls, they will not do the insulation because filling the cavity can cause the damp to travel to the internal brick skin via the insulating material.

Is your loft insulated? You should have that done as well as the walls.

[Twrch62]

They shouldn't need to test drill the wall, most walls will be double skinned, so 9" plus any render/cladding, if there is a cavity it will be around 11" plus render/cladding, so dead easy to check b4 they come.

[wowfudge]

But they will check because there's no guarantee a house doesn't already have some sort of insulation that the current owner doesn't know about, in which case you won't qualify for it for free. Unless they have changed their policy, BG won't do CWI on a house that is rendered because they drill into the walls to inject the insulating material and that can wreck the rendering.

[Twrch62]

Good point about it maybe already being done, surprised about them not doing rendered houses though, most companies do, or did.

[Lagoonablue]

Our house has rendering half way up. Defo no insulation as previous owners told us.

Will await BG verdict. Thanks all.