Tue, 19 Dec 2023 06:46:15 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283924#Comment_283924 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283924#Comment_283924 Fri, 16 Oct 2020 15:55:34 +0100 nickbartleet
Thanks!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283930#Comment_283930 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283930#Comment_283930 Fri, 16 Oct 2020 18:29:31 +0100 revor http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283931#Comment_283931 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283931#Comment_283931 Fri, 16 Oct 2020 19:14:26 +0100 tony http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283940#Comment_283940 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283940#Comment_283940 Sat, 17 Oct 2020 21:21:26 +0100 nickbartleet
I have attached the plans below. I have designed the house myself and the timber frame company did the actual frame design so no architect. The steels are in the stud walls as you can see from the drawings. Any thoughts would be helpful!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283941#Comment_283941 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283941#Comment_283941 Sat, 17 Oct 2020 21:22:31 +0100 nickbartleet http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283942#Comment_283942 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283942#Comment_283942 Sat, 17 Oct 2020 22:05:44 +0100 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283944#Comment_283944 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283944#Comment_283944 Sun, 18 Oct 2020 07:48:25 +0100 fostertom
What happens overhead? Do they support a horizontal beam similarly penetrating the roof thermal envelope?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283946#Comment_283946 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=283946#Comment_283946 Sun, 18 Oct 2020 09:02:30 +0100 revor http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=284025#Comment_284025 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=284025#Comment_284025 Wed, 21 Oct 2020 16:38:49 +0100 GreenPaddy
Draw every detail, and that in itself will start to unravel the conundrum. Air tightness must be brought into the buildup too, for example laying in pieces of membrane as the structure goes up, so you're not trying to stick tape around beams, joists, joist hangers, etc.

Build it on paper first, then you might get 80% of where you'd like to be.

Share the drawings on here, let us help you pick it apart.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=284036#Comment_284036 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=284036#Comment_284036 Thu, 22 Oct 2020 11:52:10 +0100 dickster
Both architect and builder not interested, stating that it was not necessary. My view was that the let's say -12C base of steel going straight up into warm wall would be a condensatory disaster. I lost out on this one.

Suffice to say that upon later inspections in cold/humid conditions the steel both internally and externally remains bone dry. The additional heat loss no doubt is negligable. No cold spots or mould growth.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=284055#Comment_284055 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=284055#Comment_284055 Fri, 23 Oct 2020 17:46:59 +0100 CWatters
https://enviroform-insulation.com/product/steel-window-posts-lintels/

Probably need fire rated plasterboard as well.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=286027#Comment_286027 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=286027#Comment_286027 Mon, 04 Jan 2021 18:15:53 +0000 nickbartleet
Thanks for all the thoughts. It's reassuring to see you had the same concerns as me dickster but no issues.

The house is up but not insulated yet. There are a number of steels that are flush with the external face of the osb wall. I was thinking about just using Rockwool, wood fibre or blown insulation 140mm in the walls and then wrapping the whole house in Pavatex 100mm to break these steels from the outside and then to not add much insulation on the inside of those steels (so as to further reduce risk of condensation. I was also thinking of using 10mm of Aerogel to the inside face of the steels where the windows are going to break them from the Glazing, so any thoughts on this would be great. Rockwool is far more on budget for us than wood fibre in the walls so any thoughts on this would be great. The roof is a warm deck flat roof with 275mm of Hardrock rockwool on it.

Lots of pics in full size here
https://www.dropbox.com/sh/zxx5l6qcjv85lnn/AABbGIsjwYQnyi4J5VFdOaQEa?dl=0

Any thoughts would be appreciated, or any suggestions for a good insulation supplier who can give unbiased advice on combining pavatex with rockwool in this way.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=286029#Comment_286029 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=286029#Comment_286029 Mon, 04 Jan 2021 18:48:30 +0000 tony
I would use any aerogel on the outside of them to try to mitigate the thermal bridging that they introduce, really this should be designed in rather than added afterwards.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=286110#Comment_286110 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757&Focus=286110#Comment_286110 Thu, 07 Jan 2021 13:28:49 +0000 SimonD Posted By: nickbartleetI'm sorry i never got back to anyone on here, who knew building your own house would be so time consuming!!

Thanks for all the thoughts. It's reassuring to see you had the same concerns as me dickster but no issues.

The house is up but not insulated yet. There are a number of steels that are flush with the external face of the osb wall. I was thinking about just using Rockwool, wood fibre or blown insulation 140mm in the walls and then wrapping the whole house in Pavatex 100mm to break these steels from the outside and then to not add much insulation on the inside of those steels (so as to further reduce risk of condensation. I was also thinking of using 10mm of Aerogel to the inside face of the steels where the windows are going to break them from the Glazing, so any thoughts on this would be great. Rockwool is far more on budget for us than wood fibre in the walls so any thoughts on this would be great. The roof is a warm deck flat roof with 275mm of Hardrock rockwool on it.

Lots of pics in full size here
https://www.dropbox.com/sh/zxx5l6qcjv85lnn/AABbGIsjwYQnyi4J5VFdOaQEa?dl=0

Any thoughts would be appreciated, or any suggestions for a good insulation supplier who can give unbiased advice on combining pavatex with rockwool in this way.

Hello Nick,

My recent experience of selecting insulation systems for my build has been that suppliers will typically have one or more systems they've designed that may either have BBA certification or is a registered LABC detail. You'll typically find that to derive most benefit these systems will utilise similar materials across the system. For example, using wood fibre throughout the wall structure. That doesn't mean to the say you can't build up your walls with different materials, like Rockwool and woodfibre.You just won't necessarily gain the full benefit of the system. For example, Rockwool is not hygroscopic. I have seen examples of people using mineral wool with Pavatex on timber framed walls.

I'm still rather bemused why designers design what are supposed to be energy efficient buildings with steels embedded in the walls creating such cold bridging. Our architect did the same with our build with one steel spanning the whole width of the house. I was lucky enough to be able to move the walls where this was a problem so the steels all sit within the insulated fabric of the house. I also had our structural engineer design a couple of cantilevered floors and roof in order to remove several bay window posts that would have been terrible cold bridges.The initial design was, like in your instance, to use an aero gel or similar around the bay posts. Now I have non structural timber posts instead.

I think your idea to have an external layer of insulation outside the frame and steels is a sensible one.]]>