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Mould in new extension

Discussion in 'Your Projects' started by MartinB85, 12 Sep 2021.

  1. MartinB85

    MartinB85

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    We have recently had an extension done, all signed off and the builders have done top job. We went away last week, and when we got back we’ve noticed some green mould. It was very hot last week and we left no ventilation. Most of the mould was on skirting in old part of the house we built off, this was probably because the plaster in this part was still drying and was tacked against it (its an open plan extension connecting to our old living room). However in the extension the plaster was already dry and we had done our first mist coat but at the bottom on the plasterboard green mould is sprayed across it. Its is powdery and just wipes off but i’m just worried about skirting and flooring it and it coming back. Guttering is all fine and there is more than adequate space below with air-blocks. As damp rises I wouldn’t expect the adjoining extended room which is still drying to cause this at the bottom of the wall?
     

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  2. Swwils

    Swwils

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    What's the floor made of?

    Plasterboard should not be resting in the floor at all and should have a good 10mm gap in most circumstances.
     
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  4. MartinB85

    MartinB85

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    I think the new floor is plywood with insulation underneath then from what I remember about a 2 foot gap underneath.
    This is the current gap I can see (attached). The gap isn’t consistent as you can see but the mould is on those with and without the gap.
     

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  5. MartinB85

    MartinB85

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    Is it worth me attempting to trim the bottoms with a stanley? Unsure if thats possible when hung?
     
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  7. RonnieE

    RonnieE

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    Mould needs several conditions to grow so as many of these as you can tick off, the more chance you have of stopping it returning...

    - Moisture / humidity (normally > 70% RH)
    - Warmth (that usually exists in a house)
    - Lack of air movement / ventilation
    - Lack of direct sunlight
    - An organic material to grow on (mould especially likes plasterboard) as a food source
    - Lack of disturbance (usually cleaning)
    - The presence of spores (obviously you have that)

    Hope that helps.
     
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