Cavity wall insulation

[iseethembloom]

Moved into my house in Sept 2019, so coming up for six years. It’s an old (1875 approx) cottage-style 2-up, 2 down semi. The rooms are small-ish and there isn’t much storage. The house has a door down a passage that opens to a small space - in front of which is a very steep stairway to upstairs. On the ground floor there is a room to right and left of the stairs; on the first floor there’s a bedroom to right and left. At some point, a kitchen and bathroom were added to the ground floor ‘back room’.

So, that’s the house.

In winter, it’s absolutely fecking freezing.

The boiler was installed in 1999 and it’s the non-condensing kind. It needs upgrading but I earn just a tiny fraction more than the threshold for in-work benefits, and I can’t afford it, nor can I qualify for a government assisted one.

I’m wondering if cavity wall insulation is worth it. I don’t even know if the wall has a cavity, but presume it must because if the building were single skin, i wouldn’t have been able to get a mortgage.

I’ve heard that CWInsulation can cause more problems than it solves, because if it gets wet, it causes damp.

Does anyone know if it’s worth it for a house like the one I’ve described? I’m clueless about building works.

Grateful for any advice and apologies for the length of the post.

I wouldnt have thought a house that age has cavity walls

Ours has cavity walls, its a 1929 semi, not grand enough to be 'period'.

I will never have cavity wall insulation, hence our low EPC grading, plus we cant put any more insulation in the loft without changing the joists or struts (or something). Ive heard absolute horror stories about it.

I use hot water bottles, lots of layers, heavy duty slippers, double bedspreads, hot drinks, hot baths, thick rugs.

What you might be able to do is line the walls with something like Kingspan, with plasterboard or tongue-and-groove cladding over the top?

Edited to add: you can also buy thermal lining wallpapers, might make a bit of difference.

You have my sympathy, I too froze in a similar house!

Thank you, @soupyspoonand @Beachtastic

CWI seems fraught with problems, although I’m no expert. My instinct tells me to steer clear of it.

I don't think it's an option for you OP, cavity walls weren't really used in home construction until the 20th century 😞

A house of that age is very unlikely to be cavity wall.

Old houses were built to breathe. You could install internal wall insulation but it’s risky with older construction and mortar types. Plus it would compromise your internal space.

You could consider external wall insulation, but it’s really expensive.

Putting kingspan type insulation inside the house is destructive work, and therefore expensive.

How is the insulation in the roof? I would start there as lots of heat is lost through the roof and you can insulate there more cheaply and with less disruption.

If the roof's already done, what is your budget for wall insulation?

I looked into this years ago when we were offered free cavity wall insulation and I wouldn't touch it with a barge pole. The houses on my street are stone built mid-terraces built 1870s. Honest John wrote an article advising against cavity wall insulation
in certain types of homes including stone terraces and there were hundreds of comments left by people who regretted having the work done because of the damp it had caused. I read most of them, there wasn't a single positive comment. As a consequence of this, I turned the offer down. My next door neighbour went ahead and since then they've had big problems with, guess what, damp. Unfortunately, once it's been put in it can't be removed.

Definitely start with the roof, sorry I just assumed that was done!

Thank you everyone. This confirms what I suspected and has been very useful.

We have it, it’s lovely and warm- all bloody year round. It’s particularly unbearable in summer as it seems to make the house very humid.
It has caused damp to appear and we want it removed.
The loft is insulated and so is the cellar. I wouldn’t touch it with a barge pole.

Check your doors and windows do you have double glazing and really well fitting doors? If you can’t afford anything structural then carpets with thick underlay thermal curtains and draught proofing doors all help maybe a thick curtain in front of the front door. As others have said your property would not be cavity construction anyway

I have a long heavy curtain over the door. The windows are double glazed but put in a long time ago.

i think insulting the loft and somehow replacing the boiler are the things to do. One of the upstairs rooms has no carpet, so that’s another thing.

CWI on the other hand, I will avoid. Thanks again all who have replied.

I live in an old terrace, late 1890's and it also has solid stone walls. At some point the upstairs has had internal insulation added to the external walls. It makes a significant difference during winter, it's cold but not freezing like it is downstairs. You can actually feel the temperature drop as you descend the stairs.

Several houses on the street have had external insulation added but I don't know any of them to be able to ask how effective it is.

Since moving here I've invested in an electric blanket, made all the difference when winter set in. Was actually quite toasty and didn't bother having the heating on.

In order I would:
Check guttering for leaks when it's raining.
Look at external walls to see if there are any signs of damp running down the walls (looks like a stain)
Check base of wall internally to make sure there is no damp (might need external soil level lowering).
These are because damp walls make a house much colder.
Check loft insulation and make sure it is up to modern regs so at least 300mm thick.
New double glazed windows.
Thick door and window curtains.
Check doors and windows for gaps using a smokey candle and seal if needed.
Replace carpets on ground floor with new and instm thermal underlay.
Consider insulating rooms internally with a breathable insulation like wood wool.