Green Building Forum - Insulating wall plates Tue, 19 Dec 2023 08:30:45 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302084#Comment_302084 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302084#Comment_302084 Wed, 21 Jun 2023 10:54:15 +0100 Osprey
I am planning to have the cavities filled (eps beads) of my detached house. This will leave a cold bridge at the wall plate (see attached) and possibly mould at the tom of the bedroom ceilings (I assume). I am also planning to replace the roof.

What is the best way to remove the cold bridge at the wall plate? Ideally, something that the roofers could install.

Thanks for any help!]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302089#Comment_302089 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302089#Comment_302089 Wed, 21 Jun 2023 13:17:03 +0100 philedge
Work with the roofer to start with so they know the exact detail of what you want to get the right thickness of insulation and all gaps closed up]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302092#Comment_302092 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302092#Comment_302092 Wed, 21 Jun 2023 15:10:59 +0100 Osprey
Where there any problems in keeping the rockwool in contact with the wall leaf? There is nothing supporting it in place (from the side). I assume rockwool batts can be 'jammed' under the joist overhang.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302093#Comment_302093 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302093#Comment_302093 Wed, 21 Jun 2023 16:17:37 +0100 tychwarel Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302094#Comment_302094 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302094#Comment_302094 Wed, 21 Jun 2023 17:41:32 +0100 tony
This is what I did 14 years ago

http://tonyshouse.readinguk.org/mitigation-of-thermal-bridging/]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302095#Comment_302095 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302095#Comment_302095 Wed, 21 Jun 2023 21:03:04 +0100 philedge Posted By: OspreyWhere there any problems in keeping the rockwool in contact with the wall leaf? There is nothing supporting it in place (from the side). I assume rockwool batts can be 'jammed' under the joist overhang.

We just sat the Rockwood on top of the cavity and outer leaf and the underside of the rafters held it in place. Your drawing looks to show around 200mm between top of outer leaf and top of wall plate so use 200 Rockwood cut into 200 wide strips. Once you feed it under the rafters, they'll hold it in place against the inner leaf]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302096#Comment_302096 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302096#Comment_302096 Wed, 21 Jun 2023 21:20:10 +0100 tony
http://tonyshouse.readinguk.org/wp-content/uploads/2017/08/P1040088.jpg]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302097#Comment_302097 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302097#Comment_302097 Wed, 21 Jun 2023 21:34:05 +0100 philedge Posted By: tonyDifficult or impossible to do unless done before sarking/sarking felt

OP says roof is coming off so easy access to eaves]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302098#Comment_302098 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302098#Comment_302098 Wed, 21 Jun 2023 23:07:45 +0100 Osprey Posted By: philedge
Posted By: OspreyWhere there any problems in keeping the rockwool in contact with the wall leaf? There is nothing supporting it in place (from the side). I assume rockwool batts can be 'jammed' under the joist overhang.


We just sat the Rockwood on top of the cavity and outer leaf and the underside of the rafters held it in place. Your drawing looks to show around 200mm between top of outer leaf and top of wall plate so use 200 Rockwood cut into 200 wide strips. Once you feed it under the rafters, they'll hold it in place against the inner leaf

I think the diagram overstated the gap, so maybe a bit less. I will do some experiments with rockwool.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302099#Comment_302099 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302099#Comment_302099 Wed, 21 Jun 2023 23:08:47 +0100 Osprey Posted By: philedge
Posted By: tonyDifficult or impossible to do unless done before sarking/sarking felt


OP says roof is coming off so easy access to eaves

That's the plan.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302100#Comment_302100 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302100#Comment_302100 Thu, 22 Jun 2023 07:11:54 +0100 tony Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302101#Comment_302101 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302101#Comment_302101 Thu, 22 Jun 2023 09:06:00 +0100 Osprey Posted By: philedge
Posted By: OspreyWhere there any problems in keeping the rockwool in contact with the wall leaf? There is nothing supporting it in place (from the side). I assume rockwool batts can be 'jammed' under the joist overhang.


We just sat the Rockwood on top of the cavity and outer leaf and the underside of the rafters held it in place. Your drawing looks to show around 200mm between top of outer leaf and top of wall plate so use 200 Rockwood cut into 200 wide strips. Once you feed it under the rafters, they'll hold it in place against the inner leaf

Ah, I thought you meant joistsnr ther than rafters. I can see how that might work for you, but my rafters are too far away to help. So insulation would only be held by joists compressing it.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302102#Comment_302102 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302102#Comment_302102 Thu, 22 Jun 2023 09:28:03 +0100 philedge Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302103#Comment_302103 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302103#Comment_302103 Thu, 22 Jun 2023 10:33:29 +0100 Osprey
The diagram is one I re-purposed to clarify where the problem is, rather than being drawn to scale. The actual construction is somewhat more complex (flared roof edge, very wide soffits) and I don't believe the rafters can realistically be used to hold the insulation (other tha something like the wire idea, and even then the wire would be at a low angle of incidence to the insulation, due to wide soffits).

The best I can come up with is some sort of wire 'hook' screwed to the wood at the top of the wall plate, going across the top of the insulation and down the back. Spaced at intervals between the joists. Rather fiddly and time consuming for the roofer, I suspect. Also, rockwool easily fragments, so that may not be enough support anyway.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302104#Comment_302104 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302104#Comment_302104 Thu, 22 Jun 2023 10:47:11 +0100 djh Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302105#Comment_302105 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302105#Comment_302105 Thu, 22 Jun 2023 12:02:58 +0100 tony
In my book 75mm is insufficient as I now look for 400mm of loft insulation if it is quilt.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302106#Comment_302106 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302106#Comment_302106 Thu, 22 Jun 2023 14:15:28 +0100 Osprey Posted By: djhChicken wire fastened to the outer leaf at the base and fastened somewhere appropriate on the rafters or joists or a batten attached to said should hold rockwool in place?

Attaching the chicken wire to the outer leaf is easier said than done, I think.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302107#Comment_302107 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302107#Comment_302107 Thu, 22 Jun 2023 14:20:18 +0100 Osprey Posted By: tonyInteresting to know how much insulation you can get in over the corner of the wall plate, generally there is a 100mm gap,25mm of which is needed for ventilation

In my book 75mm is insufficient as I now look for 400mm of loft insulation if it is quilt.

I will have to do some measures, but it is more than 100mm.
That would be nice, but perfect is the enemy of good. I would be happier with a 'lukewarm' bridge than a cold bridge.]]> Insulating wall plates http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302109#Comment_302109 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17873&Focus=302109#Comment_302109 Thu, 22 Jun 2023 15:37:34 +0100 djh Posted By: OspreyAttaching the chicken wire to the outer leaf is easier said than done, I think.Well you could glue it directly. Or attach a batten and fasten the chicken wire to that. The batten could be glued, or fastened using a few screws with plugs into drilled holes in the usual way.]]>