Green Building Forum - WUFI - IWI insulation 1960s house Tue, 09 Jun 2026 11:18:58 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155509#Comment_155509 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155509#Comment_155509 Mon, 03 Sep 2012 13:36:31 +0100 suegreenbuilding
I am reluctant to use phenolic - I can't see how I can effectively vapour proof it and I also understand that with offgassing it shrinks by around 2%. I will be doing both up and downstairs and into the floor space between and want to get the installation done in October before the winter sets in.

Another option I 'd like to explore is using one of the wood-fibre boards (pavatex/therm type stuff), 600mm. Could someone run a WUFI calc on this for me if they have a spare few mins?

Haven't yet worked out the construction details but would probably use insulated fixings into the interior block and through the plaster, possibly studwork over on which to fix plasterboard or OSB. That would give a breathable insulation. The ventilation in my house is to be sorted out by humidistat/active ventilation in kitchen and bathroom (it has a condensation problem at present). I am going to use a heat recovery system for the bathroom via a unit in the loft (details not worked out yet).

How breathable is plasterboard - is there anything new out there that isn't gypsum?

Thanks.

Sue]]> WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155510#Comment_155510 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155510#Comment_155510 Mon, 03 Sep 2012 13:38:42 +0100 suegreenbuilding WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155530#Comment_155530 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155530#Comment_155530 Mon, 03 Sep 2012 17:39:12 +0100 Nick Parsons
NBT will run a WUFI calc, I think. They certainly offered to for one of my clients. I imagine you mean 60, not 600mm, unless you have a very, very big house! :bigsmile:

Natural Building Technologies: www.natural-building.co.uk/]]> WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155532#Comment_155532 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155532#Comment_155532 Mon, 03 Sep 2012 18:35:12 +0100 fostertom WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155535#Comment_155535 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155535#Comment_155535 Mon, 03 Sep 2012 19:00:02 +0100 Ed Davies http://www.natural-building.co.uk/news/2011/NBT-offers-WUFI-protection.html]]> WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155578#Comment_155578 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155578#Comment_155578 Tue, 04 Sep 2012 13:16:15 +0100 djh Posted By: suegreenbuildingHow breathable is plasterboard - is there anything new out there that isn't gypsum?
There are lots of boards that aren't gypsum :bigsmile: For example, you can get clayboards (made of clay for internal walls, not the foam type you use to protect foundations)

But if you're using Pavatex or similar, you don't need any board, just plaster it direct.]]> WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155587#Comment_155587 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155587#Comment_155587 Tue, 04 Sep 2012 14:43:43 +0100 Graeme Berry WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155637#Comment_155637 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155637#Comment_155637 Wed, 05 Sep 2012 10:38:12 +0100 suegreenbuilding WUFI - IWI insulation 1960s house https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155638#Comment_155638 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9525&Focus=155638#Comment_155638 Wed, 05 Sep 2012 10:38:51 +0100 suegreenbuilding