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Cavity Wall Insulation Help - Does It Cause Damp?

Discussion in 'General Chat Forum' started by THE AMATUER, Mar 6, 2008.

  1. THE AMATUER

    THE AMATUER Active Member

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    Hi all

    Has anyone had cavity wall insulation in their home? I'm considering having it done, mainly because the council have a special offer on at the moment making it cheap, however after looking on the web I noticed several damp related problems people were having after this was completed.

    Anyone got any experiances of this or advice about it, is it worth getting it done?

    thanks
  2. gibbsy

    gibbsy Active Member

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    I've had cavity wall insulation for the past 2 years, no problems with damp even last summer. The benefits outway the worry the house is much much warmer.
  3. Mr Incredible

    Mr Incredible Well-Known Member

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    I had cavity wall insulation put in nearly 13 years ago and I have not had any damp issues. It was done by Owens Corning and came with a 100 year transferable guarantee.

    It is worth getting one of the well known contractors to do it for piece of mind.
  4. p147

    p147 Member

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    My personal advice is a big NO,anything that bridges the cavity is a bad thing:lesson:,being a builder I have had a number of jobs whereby we have taken it out,by taking down/reconstructing the outer skin of brickwork,very expensive:eek:,and these where clients that had grants.
  5. Dave Weystoner

    Dave Weystoner Member

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    I've owned the same house since 1980 -don't ask me why - and put in foam cavity insulation in the first year. I've never had any damp problems. I had it done when I was fitting central heating and the increase in heat retention allowed me to fit a wall-hung boiler instaed of a floor standing one, so it almost paid for itself straight off, without the intervening 28 years of reduced heating bills.

    Dave
  6. Raoul_Duke

    Raoul_Duke Member

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    I used to have terrible damp problems in my flat till we got the cavity wall insulation done and I've never had damp problems since.

    moisture isnt going to transfer through expanding foam, it could cross over thru steel wall ties (particularly ones which have mortar droppings on them as you know) and the like but not insulation. These people you have taken down the external leaf of the wall and removed the insulation for, were they even having problems with damp?

    Why do you think there are no dampness problems from a insulated composite wall panel?
  7. THE AMATUER

    THE AMATUER Active Member

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    Is that likely to be because the company didn't do the insulation properly in the first place? If it is a problem why is there so much advertising to get people to have it done, and backed by the councils and Energy Saving Trust
  8. Nimby

    Nimby Active Member

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    Back in the the last century there were the usual cowboys jumping on the cavity insulation bandwagon. If they didn't fill the cavity properly there would be uninsulated areas which would "sweat" indoors because they were still as cold as the unfilled wall. Hopefully the cowboys have moved onto pastures new by now. Probably messing up off-road parking areas and drives I imagine.
  9. p147

    p147 Member

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    Dont want to get you worried but the foam insulation was by far the worse,if not carried out properly because not only did they enable moiture to carry through to the inner leaf (I have taken bricks out in the middle of summer when it had not rained for weeks,and you could literally squeeze the foam as though it where a wet sponge )and susequently cause damp,but also as the foam was put in under great pressure(if you ever used foam then you know how strong and unpredictable it is) it may causes the walls to bow.
    Not sure what you mean by insulated composite wall panels,as i assume they would form part of the inner skin of a modern cavity wall.
    All modern cavity construction will incorparate cavity insulation to part thickness of the cavity and not the full depth of the cavity.
  10. Reepicheep

    Reepicheep Member

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    Sometimes what appears to be 'damp' on the inside of an external wall is actually caused by condensation on the cold surface and lack of ventilation.

    Cavity wall insulation would help to prevent this, but I can't see it preventing rising damp. Only a good damp proof course would do that.
  11. eric pisch

    eric pisch Active Member

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    as a former chartered surveryor this was allways a bone of contention, historically the cavity in the wall was a moisture barrier, bridge that and you are potentially allowing the moisture in, however many propertys dont seam to have issues and i suspect over the years the media they use has been developed to resist this

    internal condensation is anouther issue and some form of ventilation will cure this, upvc windows often cause this problem especially in older houses

    rising damp is the other good one, many moons ago the RICS did a survey of 100 propertys that "needed" chemical damp proofing, in every single case they found an underlying problem (leaking gutters, down pipes, underground pipes etc) which if fixed would have rendered the chemical treatment unnessary, they concluded unless the foundations are below the water table there was allways an underlying issue for rising damp.

    when my mum moved a couple of years ago she had damp out the back, and the builder was desperate to sell her a chemical damp proof course, until i pointed out the damp was coming from above where a lean to roof had no flashing. Fixed the roof, removed the plaster and let the wall dry, problem fixed...
  12. Nimby

    Nimby Active Member

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    A small extractor fan in the bathroom can often cure many "damp problems" throughout a house or flat.
  13. danmc_82

    danmc_82 Active Member

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    How much does it cost to have this done and how much of the house is done?
  14. ninjaryder7

    ninjaryder7 Guest

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    :thumbsup:i have been an installer of cavity wall insulation for 16 years now and i can assure everyone that so long as it is installed correctly in a suitable property then there are no adverse affects at all, prices range from around 150 to 250 depending on property type and granys availible.check your enery supplier for more info and prices.
  15. reevesy

    reevesy Active Member

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    funnily enough me and the missus have just been talking about this and i was about to post until i saw this.....
    thing is we live in a 1900 something house and the pointing is not too bad but could probably do with a bit of work but obviously very labour intensive.....
    we do get a little bit of surface mould inside the house in certain corners or behind wardrobes upstairs.......
    question is would cavity insulation cure all and do without the need of addressing the pointing?
  16. Mr Incredible

    Mr Incredible Well-Known Member

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    Some old properties have solid walls and no cavity at all. That may be the cause of some of your mold as you're probably getting condensation on the inside as the air is trapped behind the wardrobe / or still corners and the wall is cold.
  17. ninjaryder7

    ninjaryder7 Guest

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    that is correct, air flow is important, pointing should be in good order as water penetration from rain etc can affect the insulation evan though it is silicone treated,idealy repointing to be done soon afer installation for best mortar match.
  18. lance.carter

    lance.carter Member

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    Okay a bit late to this thread, but just after some expert opinions and it seems this thread had it's fair share of experts to say the least.

    Thinking of having this done in my 3 storey 1970 brick house. The ground floor is dining room/kitchen and sits essentially underground at the back and fronts out to the garden/ground level the other end. Perhaps my question is obvious but I'm worried - the room is tanked somehow and clearly will always be in danger of dampness. I guess it's a bit like a cellar/basement if you like. Surely putting CWI in there has to be questioned. Has anyone come across this, or have any thoughts to share?

    Thanks in advance.

    p.s. yes obviously I'll get proper advice from reputable company with correct accreditation etc but imagine if it does go horribly damp, the hassle/trouble is going to be huge, even if a reputable company will sort it out.
  19. eric pisch

    eric pisch Active Member

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    make sure any work you get is covered by an insurance backed scheme for 25 years+ at least that way if there's a problem and the firm has ceased trading you have some redress.

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