Internal Moisture

Discussion in 'Builders' Talk' started by Rigga, Dec 1, 2009.

  1. Rigga

    Rigga New Member

    Hi all, (be gentle first post :))

    We have a house built in the 1930's we had a problem with internal damp / mold last year, so had the DPC redone. This seemed to solve the damp / mold problem during the summer.

    However now we are getting lots of internal moisture in the house, it's causing mold to appear on lots of the internal walls. It's particularly bad in the kitchen. We also suffer from horrendous condensation, I mean literally water pouring off the windows, and collecting on the sills.

    Just wondering if there could be an underlying problem I haven't noticed / don't understand? or is it just lack of internal airflow?

  2. threadbreeker

    threadbreeker New Member

    sounds like a problem with the house itself. I suggest demolishing n d rebuilding.
  3. flippin heck

    flippin heck New Member

    Within the home, the kitchen and bathroom are the big contributors, but moisture is also produced by damp clothing left to dry in the house and even breathing.
    The best you can do to combat the problem is firstly to have an understanding of the subject and put measures in place to control it.
    Condensation is all to do with relative humidity, which is the measure of moisture (volume) in relation to air temperature, and Dew Point. When the moisture carrying capacity of the air reaches its maximum (Dew Point), the excess moisture condensates when it touches a cold surface. However, because warm air is capable of carrying more moisture than cold, condensate will occur sooner in a cold area.
    If you remove moisture from its source with extractor fans in the kitchen and bathroom, keep the kitchen and bathroom doors closed, keep rooms warm and provide adequate ventilation you will see a big difference.
  4. trench

    trench New Member

    having the dpc done would have probably involved replastering and this would have thrown out water as it dried.

    or have you had new DG windows put in recently too? if you have, look at improving the ventilation as the new windows will be less draughty than the old ones and drafy windows made for good ventilation, which is now gone.

    Sort out some background ventilation and an extract fan and look at your condensation causes. do you dry clothes on the radiators? for instance. And even putting half an inch of cold water in the bath before you run in the hot (rather than the other way round)will cause way less steam.

    When you are dealing with condensation probs, the way you are using the house is often as much to blame as the construction itself. Good luck
  5. Teuchter

    Teuchter New Member

    Hi Rigga.

    Your house is probably quite normal. As you suspect, it's likely to be due to a lack of ventilation - not internal flow, however, but ventilation to the outside.

    If all the ,say, bedrooms are similarly affected at the moment, then try for one cool night cracking open the windows to 'vent' position in one of them. Compare results in the morning. Fair bet that that room will have significantly less condensation.

    Lots of moisture is produced in every home - cooking, washing, baths, drying clothes, and breathing. This moisture is supported by the warmer air you maintain during the day and evening with your heating system.

    Once you go to bed - and turn off the heating - the air cools and this trapped moisture condenses out on the coldest surfaces - windows and external walls.


    1st make sure you are producing as little as possible, or at least, getting rid of it as it's being produced - extractor when cooking, vent fan or wondow part open when showering, etc. (If that last one is too chilly for you to contemplate, then open the window wide after showering/bathing and shut the bathroom door. Leave to fully vent.)

    And/or, keep the heat on 24/7. (silly...)

    And/or, make your walls warmer - cavity insulation, insulated lining on the inside (thin foam type stuff), etc. Add double glazing.

    And, improve ventilation at night.

    If you already have double glazing and your windows are streaming, then your windows are already pretty 'warm' so the cause must be either too much moisture being produced, or not enough ventilation.

    I have a 30's house too, fully d/g, and cavity wall insulation. On the recent colder nights, I still get a line of condensation along the bottoms of the panes in some rooms - I just wipe it up first thing. However, it is slight because the kids bedroom doors are kept ajar, the bathroom window is always cracked to 'vent', and the rest of the house is also allowed to 'circulate'. Some condensation shouldn't come as a surprise, but lots needs to be tackled.
  6. Rigga

    Rigga New Member

    Thanks all for the replies. Except threadbreeker obv.

    All the rest, useful info.

    I will summarily ***** the missus next time she dries the washing on the rads. :)

  7. palavaman

    palavaman Well-Known Member

    pls whatever u do,donot ***** the missus. that is classed as ABUSE:D

    I do not want 2B ringing the child protection agency?
  8. Big Jumbo

    Big Jumbo New Member

    I'd be more concerned about him having a child bride...this is not Missouri you know!
  9. thebigragu

    thebigragu New Member

    There's the problem then.

    Water exists in three states - solid, liquid and gas.

    When you run a hot bath, dry clothes, cook, boil a kettle - you are filling the air with water vapour(gas).
    That water vapour circulates the home until it finds a place cold enough to turn back to liquid, like windows, bottoms of walls, etc.

    Either don't create water vapour of get rid of it with an extractor fan in kitchen and bathroom or a dehumidifier.

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