Water Droplets on Joists under sub-floor

Discussion in 'Builders' Talk' started by cameron mackenzie, Sep 8, 2020.

  1. cameron mackenzie

    cameron mackenzie New Member

    I live in a bungalow, which has a sub floor ,with an approx 800 mm void. The Bungalow is approx 20 years old and has chipboard flooring. I have been getting a musty smell in one of the bedrooms only. I went under the floorboards to have a look and noticed that there were some water droplets on the bottom of the joists and that a part of the insulation was wet. (Joists look OK, no excessive damage) I also noticed that when we have heavy rain, water gets into the void (Water Tables). I am assuming water droplets on the joists is condensation. I also noticed that the bedroom has 3 brick air vents, which have been partially covered over with mortar on the inside (Don't know why). I am planning in doing the following to try and address this issue and would appreciate your feedback on the ideas and is there anything else I could do to remove the condensation.
    • Clear all 3 air brick vents and ensure any other air brick vents around the house are also cleared.
    • Ensure guttering outside is OK, with no leaks.
    • Ensure the slabs outside the bedroom are sloping away from the house.
    • Replace any wet insulation with 100mm insulation board.
    • Use a dehumidifier in the bedroom.
    • Possibility of looking at a pump to remove any water ASAP.
    Many Thanks.
     
  2. nigel willson

    nigel willson Screwfix Select

    All the above good , especially the cleaning of air vents, very important
     
  3. Dan Parkinson

    Dan Parkinson Active Member

    I have the same problem, and will be addressing it the same way. However I already have plenty of air vents and they're all clear. No matter what anyone says, a stiff breeze won't get rid of the 2000 litres of water under my house.
     
  4. ElecCEng

    ElecCEng Screwfix Select

    Consider a membrane on the bottom of the joists. It will stop any moisture in future getting into the insulation. Also moisture will condense on it and drip back onto the concrete ready for pumping.

     

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