Black Mould appearing on North facing wall

Discussion in 'Homes and gardens' started by pinkyBear, Feb 5, 2007.

  1. pinkyBear

    pinkyBear Frequent Poster

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    Hi all,
    I have noticed a problem on our North facing walls. There is black mould appearing on them. My brother in law told me if I clean it off with bleach it will disappear- not so.

    I repainted the room and we bought this damp proof sealant and put it on the walls - guess what its back!

    We currently have single glazed windows and are in the process of getting double glazed windown in during the summer.

    Is this mould something more sinister than the fact that we have single glazed windows, or will we have to get more specific treatment to rectify this.

    Many thanks,
    P:)
     
  2. ClubMan

    ClubMan Frequent Poster

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    Is the room adequately ventilated?
     
  3. bobcaw

    bobcaw Guest

    sounds like damp to me?? is there any drains blocked near the wall??
     
  4. landlord

    landlord Frequent Poster

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    One of the major problems with single glazing is that in the winter, they do not provide enough insulation and therefore the room tends to get cold. As a result one tends to close the windows and the vents to try and keep the room warmer. This stops the ciculation. If you combine this problem with moisture in the room from for example a bathroom close by or clothes drying in the bedroom, it will make the problem much worse. Also I had a tenant who suffered from all of the above refused to turn the heat on ever in the bedroom so the room never dried out. This room developed a very serious case of damp. Fortunately the problem is not so bad coming into the summer months. As air warms up it is able to hold more water in the form of vapour and therefore you will notice less condensation on the windows/walls/ceiling. Thus generally heat and ventilation usually are key to avoiding damp and therefore mould. Good Luck
     
  5. ted

    ted Frequent Poster

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    I'm having the same problem with a new build and double glazing. Invest in a Hygrometer - digital ones available on eBay. The Relative Humidity should be between 40 and 50% in winter - maybe lower if you've single glazing. You might need a dehumidifier (local tool hires have them for about €90/week for a large one) and then heat and ventilate the rooms affected and monitor RH levels.
     
  6. pinkyBear

    pinkyBear Frequent Poster

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    Hi there, there is no vent in the bedroom that I can see. But the sitting room has a vent that isn't blocked... :confused: and the wall is very bad...

    There are no drains blocked near the wall and it is affecting both downstairs and upstais walls. I usually have the heat on for about 3 hours in the evening.

    We are planning to get the windows done this summer, so I'm hoping that will aleviate the problem but judging by teds post - this is not always the case:(
     
  7. ClubMan

    ClubMan Frequent Poster

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    Regardless of the sitting room having a vent and still suffering from the same problem, not having a vent is not a good idea as far as I know.
     
  8. serotoninsid

    serotoninsid Frequent Poster

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    Last edited by a moderator: Feb 6, 2007
    Was at a recent Homebond presentation and they said that they are finding this problem more and more. Its probably a case of homes being built with energy efficiency in mind - they are becoming more airtight - but maybe to the detriment of adequate ventilation in cases..

    Have exactly the same problem as the OP. Most important thing is to satisfy yourself that its not water ingress through the external walls - as this would be a major issue.

    I think in my case, its as a result of the room being next to a bathroom that isnt ventilated.

     
    Last edited by a moderator: Feb 6, 2007
  9. nossie

    nossie Registered User

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    I have a damp problem in one very small bathroom that has no radiator in it and circulation is not the problem. It's a solid outside wall that is very cold and when the warm air from the house enters the room it condenses on the wall and over time this has built up to fungus. I think the only remedy for me is to put a tiny radiator in there to warm the walls and reduce the temperature difference.
    Maybe this a possible cause for you too.
     
  10. c71

    c71 Registered User

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    27
    Have the same problem myself and was on to my local friendly paint guy about it. What all the above folk say is true - circulation etc.

    However, he did suggest using a certain type of porous paint that would allow the wall to breathe and prevent the mould from forming ( I've forgotten the techie bits as it was some time ago and I've yet to buy it). Anyhow, it's called Steracil and you can buy it in specialised paint shops...it comes in white only but they can tint to lighter colours no problem.

    Might help you!
     
  11. feorais

    feorais Frequent Poster

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    Here is the problem: Warm moist air migrates to the cold wall surface and forms a mouldy appearance. Your option is to dry line the exterior walls by using a Kingspan product, get technical advice from them. You will now find that the warm moist air will settle more on the next coldest surface, ie the windows. Each morning you may dry off the windows with an absorbent cloth. Get yourself a dehumidifier, and use it each day in cold weather, it will collect a lot of the moisture from the atmosphere and help to allay the problem. Please note that even double glazing still does not prevent the moisture from forming, but at least it is easy to dry the window(s) every morning, less than 5 minutes work. There is now a vent available which helps to air the room without subjecting the occupants to a very uncomfortable draught, a bit pricey but anything worthwhile is worth it. There should be a regular heat source used in the room, perhaps not all the time but when occupied at least. The worst room in the house for producing condensation will usually be the bedroom;it is incredible the amount of moist warm air produced by , say 2 persoms sleeping in a bedroom, you will see evidence of this every morning. This happens even if you have the window open.
     
  12. Franm

    Franm Frequent Poster

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    Also check where your bathroom extractors vent to. I found that two of our vents just went to the attic above a fitted wardrobe which I feel caused a major damp/mould problem in this area (even inside the wardrobe).

    Franm
     
  13. money man

    money man Frequent Poster

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    Ring Homebond and ask them to post you out their ..condensation in your home ...handbook. Its very good and informative. its more common these days due to new building techiniques making the home more airtight.
    I think the above suggestion re:paint is not a good one and would be a waste of money. the only answer is adequate ventilation and heating the air because warm air takes more moisture from the air and the ventilation will take it outside to the cold. Meaning less moisture building up on your walls= no black spots. Paint= waste of money/time/ and a tidy wee job for the painter that gave you the friendly advice!
     
  14. money man

    money man Frequent Poster

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    Homebond: 1850 306 300. or headoffice@homebond.com

    you may have to be registerd with them(your house that is) if it was built in the past 10 years it probably is.
     
  15. pinkyBear

    pinkyBear Frequent Poster

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    Hi there,
    Great to see a thread grow - we have just had a quote for Double glazed windows, but I am going to contact HomeBond straight away. Many thanks to all those who have answered my query.
    Pinky:)
     
  16. babaduck

    babaduck Frequent Poster

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    Bear in mind that HomeBond cover STRUCTURAL issues only & poor or inadequate ventilation doesn't fall under the auspices of this scheme - their Homeowners Handbook makes this very clear
     
  17. lizzyd66

    lizzyd66 Guest

    I had this in my old flat - as previous posters said it is really the opposite to damp - if your wall is not porous at all then condensation will settle on the wall . It is particularly bad if you have furniture etc pushed against the wall. I used to have a bookcase in that corner and when I moved it it was dreadful behind it. Once I moved the bookcase it didn't return.
     
  18. Muzzy

    Muzzy Registered User

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    do anyone know of a good fungicide that you can use on interior walls? we are currently having the same problem. we intend to paint the enterior of the house in the summer so hopefully this will seal the wall somewhat. The house is about 70 - 80 years old.

    thanks,

    Muzzy.
     
  19. pinkyBear

    pinkyBear Frequent Poster

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    Hi there Muzzie,
    I am on the prowl as well for fungicide if you get advise would you mind posting it.

    Many thanks,
     
  20. dimple

    dimple Registered User

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    I bought a bottle of HG Mould Spray in Woodies a few weeks ago. It was around 15 quid for a half litre spray and its brilliant for spraying along the areas affected by mould - it has a strong bleach smell from it but when you spray it on it will eat away at the mould on paintwork, silicion etc. Within half an hour all of the mould will disappear. However, this doesnt resolve the problem of the mould in the first place it only helps to keep it under control..