Cavity Wall Insulation in a 100 year old Terraced House

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Suddickbender

Well-known member
Has anyone had cavity wall insulation installed in a terraced house or has anyone any thoughts / Knowledge / Experience of having it installed ?
 
As said above all new build houses today have to have it by law.

We’ve just moved into a new house just before Christmas and the difference is just immense we hardly ever have the central heating on and when we do it’s just for an odd half an hour or so.

We got it done 25 years ago in a then new build house after about 10 years of living in it and it was the best thing we ever did it lowered my heating bills by about a third get it done professionally and use the right stuff and it’s fine we had no issues at all.

Can’t comment on a 100 year old property but we sold up from a 60 old bungalow that didn’t have it and we couldn’t have it as the cavity’s were too narrow (only 25mm) it was the coldest house we’ve ever owned hence we couldn't wait to move.

As warm as toast these days and we’re paying less for our energy bills now in a 3 bed detached house than we were in a 2 bed bungalow.
 
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Modern cavity wall insulation isn't the same as the foam type stuff that you'd put in an existing building. Don't touch it and investigate other insulation methods.
 
Who is the local reputable firm to go to for cavity wall insulation ?? When I had mine done 15 ish years ago I didn’t notice much difference in my gas consumption,I suspect it may not have been done correctly ?
 
We had those beads in our previous house. Had to fight some company to get them removed free of charge because it was causing damp. I'm sure newly fitted insulation would be fine.
 
RUSTY_2_STANDS said:
It's suitable for most properties if it's installed correctly.
And whoever mentioned air flow in a cavity is talking nonsense.
Why do you think cavities are closed? You don't want air moving around in them.

Not correct
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Correct. Most people don't have a jar of glue as to the pros and cons of cavity wall insulation. As a rule, it's the best thing you can do, but not to be installed by charlatans.
 
Cavity walls were not designed to insulate homes, but to manage water soaking through porous bricks and stone. When you fill cavities with foam/polystyrene beads/fibre this retains penetrating water and can lead to
  • Damp penetration caused by bridging the cavity.
  • Cold spots
  • Mould
  • Condensation
  • Damaged brickwork
  • Structural problems
  • Health problems, particularly respiratory conditions.
Obviously, the above applies more to older houses as it takes several years for the problems to arise. A Which report concluded that there is a significant chance that damp will occur in properties as a result of cavity-wall insulation if there is a combination of these factors:
  • the property is exposed to severe levels of wind-driven rain
  • the property is located in an unsheltered position, eg not protected by trees or other buildings
  • internal walls are poorly built or maintained with, for example, cracks in the brickwork or rendering.
 
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RUSTY_2_STANDS said:
It's suitable for most properties if it's installed correctly.
And whoever mentioned air flow in a cavity is talking nonsense.
Why do you think cavities are closed? You don't want air moving around in them.

Not correct
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Rubbish, the airflow ensures that the internal wall stays dry . Cavities are closed but we still have ventilation at low and high levels. If we fill the cavity it causes condensation which in turn, leads to mould forming . I have well over 40 years in the construction industry so I’ve got an idea what I’m talking about . New build houses have cavity insulation but they still have 50 MM clear air flow.
 
Basically it’s the same as lofts . A builder told me you should never ever put any items in your loft , it’s there to let your house breathe , and it can’t when it’s full of crap .
 
Fatboy said:
Rubbish, the airflow ensures that the internal wall stays dry . Cavities are closed but we still have ventilation at low and high levels. If we fill the cavity it causes condensation which in turn, leads to mould forming . I have well over 40 years in the construction industry so I’ve got an idea what I’m talking about . New build houses have cavity insulation but they still have 50 MM clear air flow.
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Ever heard of drithem?? You are talking shite it has zero to do with airflow and everything to do with water not penetrating to the inner skin.
 
Fatboy said:
Rubbish, the airflow ensures that the internal wall stays dry . Cavities are closed but we still have ventilation at low and high levels. If we fill the cavity it causes condensation which in turn, leads to mould forming . I have well over 40 years in the construction industry so I’ve got an idea what I’m talking about . New build houses have cavity insulation but they still have 50 MM clear air flow.
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No they don't in a lot of cases. I put an extension on my previous house 20 years ago with full fill cavity insulation.
I left that house a few months ago and not a hint of damp. Nothing to do with air flow. Why have air flow in a cavity?
 
RUSTY_2_STANDS said:
No they don't in a lot of cases. I put an extension on my previous house 20 years ago with full fill cavity insulation.
I left that house a few months ago and not a hint of damp. Nothing to do with air flow. Why have air flow in a cavity?
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When I had my cavity wall Insulation they put air bricks in also?

Best thing I had done(free) over ten years ago my heating bill went down massively.
I now need it doing again as also had an extension(fully insulated)built last year and it was like a snow cannon going off when they knocked down the walls.
I'm still finding insulation balls now!

We are not benefits and earn above the limit to get a freebie so looking for someone to do it local.
 
poolseasider said:
When I had my cavity wall Insulation they put air bricks in also?

Best thing I had done(free) over ten years ago my heating bill went down massively.
I now need it doing again as also had an extension(fully insulated)built last year and it was like a snow cannon going off when they knocked down the walls.
I'm still finding insulation balls now!

We are not benefits and earn above the limit to get a freebie so looking for someone to do it local.
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I can't understand why they would put air bricks in? Unless they're at low level(?) to ventilate under your floor
Good to hear though the cavity wall insulation did it's job in reducing your heating bills 👍
 
RUSTY_2_STANDS said:
I can't understand why they would put air bricks in? Unless they're at low level(?) to ventilate under your floor
Good to hear though the cavity wall insulation did it's job in reducing your heating bills 👍
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Yep near the ground so your probably right. 👍
Just need to start to getting some quotes to have it done again!

And to all those who say don't get it done my extension is the warmest part of the house and had to be fully insulated just to pass building regs.
 
If anyone has concerns ask the installer to provide a condensation calc. If they are competent they'll know what you're on about and secondly it will prove that the dew point is not occurring within the fabric of the building, which would create dampness via condensation.
 
Leither said:
Cavity insulation used to partially fill the cavity which is usually 100mm . . nowadays full fill cavity insulation is pretty standard.
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Different materials when used on older houses to new builds? Different levels of standard of outside brickwork and therefore moisture transfer?

I saw with a neighbour (bloke's a tosser.... I digress) that their damp problem was due to the aging outside drainage system and the damp rising (there's no CWI). I wonder if CWI would have made the problem worse by drawing the damp up further and quicker.
 
Doubt it’ll have cavity walls if it’s 100 years old
It’ll probably be 9inch solid brick.
Cavity walls were about 1930’s.
I’m a surveyor by the way 😂 There were some at that time but not many pre 1920 houses were cavity
 
CAGU said:
Doubt it’ll have cavity walls if it’s 100 years old
It’ll probably be 9inch solid brick.
Cavity walls were about 1930’s.
I’m a surveyor by the way 😂 There were some at that time but not many pre 1920 houses were cavity
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100 years ties in with the 30's to be fair.
Out of interest what kind or surveyor are you?
 
CAGU said:
I worked for the Valuation Office most of my career then for Countrywide Surveyors doing Homebuyer Valuations and mortgage surveys
You?
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Worked in building control for 28 years and for last 5 set up a consultancy that does plan checking and site inspections. I also do insurance work for a loss adjuster to defend uplift claims to meet potential statutory uplift requirements.
 
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