Dew point concern?


I am buying a loft in Kaunas, Lithuania. I will own a top floor apartment and the issue is that roof is not insulated, so I have to do that from inside. My biggest concern is the dew point.

Roof only has ~20cm of expanded clay (Keramzitas in Lithuanian) as insulation.

I plan to do 15-20cm of polystyrene insulation. I will install an A/C (with external unit outside) and will have mini recuperation system to have some sort of air circulation.

Should I worry about Dew Point?

1 Answer

  • Anonymous
    8 months ago
    Favourite answer

    Expanded clay should give you some insulation value, but the key thing is how the entire envelope performs. The problem you have with insulation underside is arranging ventilation which may be necessary if you are to avoid problems with the dewpoint occuring where you don't want it. You need to do a detailed calculation which is rather beyond the scope of YA.

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