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Can cavity wall insulation cause dampness?

Interested to hear if anyone else has had problems with dampness following cavity wall insulation?

I got mine done in 2005 and just before Christmas this year I noticed two large patches of damp and dirty marks on the wallpaper on my gable end wall. I finally traced the installers (not easy) and they sent a surveyor to look at the damage a couple of weeks ago.

He left saying he needed to speak to a manager and would get back to me the next day (I asked but he wouldnt say what caused the problem).

Several phone calls later (me chasing and all sorts of promises to get back to me!) I was then told "oh, you have an appointment booked in for the insulation to be redone on 15 March"?? eh, who was going to tell me this; did the date suit me etc etc??:mad:

Anyway, still no comment on what has caused the damp patch and damaged wallpaper.

several questions:
will them redoing the insulation solve the damp problem?

how do I get rid of the damp thats already there?

can I get them to pay for the damp work and repapering? This is the hall and stairs - so will they pay to repaper the whole hall upstairs and down?? Do I have to let them do the papering or can I get someone else to do it and send them the bill (are they decorators as well as insulators??) I had got decorators in to do the hall because of the high ceilings - about 1.5 years ago.
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Comments

  • anotherbaldrick
    anotherbaldrick Posts: 2,335 Forumite
    edited 22 February 2012 at 6:33PM
    They need to remove some external bricks and scrape off the mortar droppings from the wall ties . These droppings are an inheritance from the original builder who should have cleaned them as the wall was built up The mortar build up on the ties allows them to conduct moisture over the cavity. The insulation contractors should have checked the ties were clean before they pumped in the insulation Naughty, naughty.
    You scullion! You rampallian! You fustilarian! I’ll tickle your catastrophe (Henry IV part 2)
  • Thanks Baldrick! That explains some of it for me... But hope you don't mind me asking more?!

    House was built 1930's or 40's ex council semi. Presume it was breeze block originally and was rendered later?

    So if they redo the insulation by just filling it up more will the problem reoccur? If so do I just say no thanks? Or what should I ask them to do to prevent another episode?
  • tony6403
    tony6403 Posts: 1,257 Forumite
    Part of the Furniture 1,000 Posts Combo Breaker
    More likely to be voids causing condensation where warm air meets cold (uninsulated ) surface.
    If the wall ties are coated in mortar your property might have been subject to damp before insulating the cavity. Never seen brickwork removed to check wall ties before insulating.
    Forgotten but not gone.
  • Therese1
    Therese1 Posts: 160 Forumite
    Tenth Anniversary 100 Posts Combo Breaker Mortgage-free Glee!
    Thanks Tony,

    but why would the damp suddenly appear now - and spread so quickly - the wallpaper is very stained and its even penetrating the cornicing quite deeply?
  • Leif
    Leif Posts: 3,727 Forumite
    Have you checked for other causes of damp, such as a blocked drain pipe? I know little about damp, so hopefully someone else might give you further suggestions. If the insulation has been okay for over 6 years, that does raise the question of why it has now gone awry.
    Warning: This forum may contain nuts.
  • CWI can highlight an existing condensation problem

    You need to be clear whether this "damp" is penetrating or condensation
  • swift1_2
    swift1_2 Posts: 130 Forumite
    Part of the Furniture 100 Posts Combo Breaker
    We've got damp on our bedroom wall just below window in the corner. Recently had the loft insulated, they said the walls already had insulation in them. Asked them what could be causing the damp, they reckon over time a gap has formed around that area of the wall and thus when warm hits that area which is cold it condensates hence the damp. He recommended either getting it checked and filled again or putting in an air vent.
  • patman99
    patman99 Posts: 8,532 Forumite
    Part of the Furniture 1,000 Posts Combo Breaker Photogenic
    What sort on cavity insulation did they use ?. The two-pack foam one is known to break-down and act like a giant spong over 25 years or so, but the blown-fibreglass stuff tends to be stable and allows a slight up-current of air in the cavity.
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  • tony6403
    tony6403 Posts: 1,257 Forumite
    Part of the Furniture 1,000 Posts Combo Breaker
    Therese1 wrote: »
    Thanks Tony,

    but why would the damp suddenly appear now - and spread so quickly - the wallpaper is very stained and its even penetrating the cornicing quite deeply?
    If you have rockwool type insulation it is possible that it has slumped and created a cold spot which will attract condensation.
    If you have polybead insulation which didn't have adhesive applied as it was installed, the beads could be escaping (sometimes under the ground floor where the odd bed joint or vertical joint in the unseen internal brickwork has small gaps). This will allow the beads to fall producing voids higher up.
    It may be that your insulation is fine and that you have other problems such as displaced roof tile(s) or leaking gutters.
    I would let the company sort out any insulation issues and then ask if they intend to redecorate.
    Forgotten but not gone.
  • rebecca1974
    rebecca1974 Posts: 1 Newbie
    edited 24 February 2012 at 12:51AM
    I would have them drill a hole and check the areas with a borescope to see if voids are causing the problem. Thermal imaging doesn't cost the earth and would also spot missing areas of insulation a mile away, if they fail to solve the problem have this done then for proof and go back to the company with proof that the insulation has caused these issues. All cavity installation work must adhere to the ciga rules so contact ciga, easily found on google.

    regards
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