Is cavity wall insulation a good idea?

edited 21 June 2010 at 5:12PM in In My Home (includes DIY) MoneySaving
20 replies 32.6K views


  • LeifGRLeifGR Forumite
    188 Posts
    Dry_Rot wrote: »
    This guys has many opinions - That's what they are. He has a column in a national newspaper - that is as far as his expertise goes.
    I accept that. What I was trying to understand (genuinely) was whether foam or bead cavity insulation does indeed take up to 2-3 days to do, whether it is indeed much more expensive than fibre and whether Gizmosmum was only talking about fibre in her/his post.

    @C_Mababejive: Couldn't agree more. Huf houses specifically are out of reach for the genral public but the principles are sound and could be utilised in normally-priced housing.
  • edited 25 June 2010 at 9:10AM
    mudcow007mudcow007 Forumite
    8 Posts
    edited 25 June 2010 at 9:10AM
    i have just had my cavity walls done, i thought it was foam that was squirted in? turns out they use polystyrene balls with glue that fills up the gaps..

    supposedly mine was partly paid for by N-Power and only cost me £100, im not on benefits etc

    it took the guys who did my house about 2 1/2 house (mines a tiny semi)

    a thing to note though....its messy, there are polystyrene balls all over the garden!
  • Gizmosmum_2Gizmosmum_2 Forumite
    448 Posts
    LeifGR wrote: »
    Thanks. What I was referring to was this information from the Sunday Telegraph columnist Jeff Howell:
    In your post above, were you referring only to fiber-type cavity insulation, or is the Jeff Howell info incorrect?

    Foam insulation is rarely used in the UK now - although I'm sure someone will know about some exceptions. There were issues with areas of high exposure and it became much less popular as a result. Polybead is used my many installers now and attracts the same utility discounts so you shouldn't be paying any more for it and it takes 2/3 hours to install. It's quite popular at the minute because you need to drill about 1/3 less holes than for mineral wool and so it looks a bit better when it's finished. If you go down this route make sure they glue the beads together - if they don't and you change windows etc in years to come you'll empty your cavity before you can say "saving energy":rotfl:

    Whichever product you chose there are rarely any problems I worked for a local authority encouraging this type of work and was responsible for the installation of approx 15,000 properties over 5 years. We had an odd problem but you could count on one hand the issues that we had and most were resolved very quickly by the installer. OUr Building Control Officers all had cavity wall insulation installed and you won't get a much better endorsement than that!;)
    Target of wind & watertight by Sept 2011 :D
  • 27col27col Forumite
    6.6K Posts
    I have had insulating foam in my walls ever since I built the place over 30 years ago. Never had the slightest problem either. The back of the house is quite exposed to the prevailing wind and rain. I had the foam installed from the inside so that there is no trace of any holes in the exterior brickwork. I would certainly, never willingly live in a house that did not have cavity insulaltion.
    I can afford anything that I want.
    Just so long as I don't want much.
  • lomblomb Forumite
    46 Posts
    The best insulation is that done on the inside like kingspan. This stops heat dead from escaping in the first place and warming the inner leaf and has built in vapour barriers. Anything else is hit and hope even modern building with insultion tied to the inner leaf in the cavity.
  • dampdaveskidampdaveski Forumite
    529 Posts
    LeifGR wrote: »
    Sorry if this has been covered; I did a search but could not find an answer.

    We were going to have cavity insulation done for our 1982-built house but when I was reading up on the different types available (fibre, foam, beads) I came across this article:

    This guy is clearly putting forward some powerful arguments against cavity wall insulation. Has this topic been debunked on the forums? If so, could some helpful soul point me in the right direction?

    leif I would happily have the beady glue type cavity insulation fitted in my house.

    As for Jeff, I wish him a very merry christmas and a prosperous new easter ;)
    The advice I give on here is based on my many years in the preservation industry. I choose to remain anonymous, I have no desire to get work from anyone. No one can give 100% accurate advice on a forum if I get it wrong you'll get a sincere apology and that's all:D
    Don't like what I have to say? Call me on 0800 KMA;)
  • 25rts25rts Forumite
    50 Posts

    Sorry if someone has already brought this up:

    A friend sent me a link for a consumer program which was on BBC1 a month or so ago which unfortunately isn't on BBCi player where due to not undertaking a pre-installation survey the homeowner ended up with dry rot as the 'balls' had blocked the airbricks as there were no cavity liners.
  • Dry_RotDry_Rot Forumite
    51 Posts
    Hi 25rts

    Yes - But bear in mind that this was clearly a case of poor workmanship. It wasn't the fault of the insulation material, just the fact that the air bricks were not sleeved or protected from invasive insulation by cavity brushes or similar. It shouldn't put you off, but do use a properly qualified and accredited installer and mention your concerns when they come to do the survey.

    The expert who confirmed that the poor ventilation contributed to Dry Rot was renowned industry expert, Graham Colman - top bloke.

    Dry Rot
  • 25rts25rts Forumite
    50 Posts
    Hi Dry Rot,
    A chicken or egg situation. If they hadn't have had the walls insulated they probably wouldn't have ended up with dry rot. If the Company had carried out a pre-installation survey they probably wouldn't have ended up with dry rot. If someone had accepted responsibility sooner the outbreak would not have been so widespread..............................
    I would be interested to know if another source of dampness was found I don't recall anything being disclosed do you?

  • dampdaveskidampdaveski Forumite
    529 Posts
    this post is like milk - its Brill!!
    Of course the blocked air bricks which will reduce air changes in the sub floor void, and thus help to create a more humid 'atmosphere' in itself will not be the ONLY cause of a dry rot outbreak. The 'spores' must have been present in the sub floor void of the property in the first place to have germinated when the right environmental conditions were met by said airbricks being blocked with beads.
    Or alternatively the beads did not cause the actual source of moisture (i.e. I presume a damp oversite), they merely facilitated the build up of moisture etc etc, yada yada yada
    This thread has been off topic more times than David Cameron has blamed labour in his speeches :)

    A good survey, the right questions to the 'surveyor', beads and glue, you are unlikely to go wrong ;)
    Merry Christmas
    The advice I give on here is based on my many years in the preservation industry. I choose to remain anonymous, I have no desire to get work from anyone. No one can give 100% accurate advice on a forum if I get it wrong you'll get a sincere apology and that's all:D
    Don't like what I have to say? Call me on 0800 KMA;)
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