Mon, 27 Jul 2026 15:47:20 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277715#Comment_277715 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277715#Comment_277715 Sun, 05 Jan 2020 21:39:55 +0000 benawhile I have found info relating to condensation forming on the underside of loft boards if an air space is not left between the top of the insulation and the underside of the board, but cannot find any definite statement about whether standard loft board is, or should be, water vapour permeable.

There definitely is information on the net to imply that ”building materials “ such as ceiling plasterboard, ARE permeable, and so on pre 1970s houses there is a risk of condensation on the underside of loft board.

Is it best to assume loft board is not permeable, or are there some board materials that have a certain amount of permeability?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277723#Comment_277723 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277723#Comment_277723 Sun, 05 Jan 2020 23:25:23 +0000 tony
Even with an impermeable ceiling or vapour barrier this is still important]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277744#Comment_277744 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277744#Comment_277744 Mon, 06 Jan 2020 19:02:03 +0000 benawhile https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277797#Comment_277797 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16381&Focus=277797#Comment_277797 Wed, 08 Jan 2020 12:49:19 +0000 tony