Green Building Forum - Cold bridge-free thresholds for heavy sliding/bifold doors Tue, 19 Dec 2023 08:28:29 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273087#Comment_273087 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273087#Comment_273087 Thu, 28 Mar 2019 14:11:03 +0000 lineweight Posted By: Doubting_Thomas
Posted By: lineweightIs it offered as a 'system' by GBS? In other words if you give them the dimensions, weight of your door frame etc can they confirm whether this detail will work?


I don't think so, I'm afraid.

From memory I ended up doing some rough calculations that others on here helped out with. See second half of this thread: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11503&page=1

The safety factor was big enough that I felt comfortable using it. Plus I also checked it with the supplier of the Isoquick and the Sliding Doors and it's a fairly standard approach.

Thanks, was useful to have a read of that thread.]]> Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273088#Comment_273088 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273088#Comment_273088 Thu, 28 Mar 2019 14:21:58 +0000 lineweight Posted By: lineweightComing back to this... further investigations brought me to "structural cavity closers" and products from Cavalok who seem to be part of Eurocell.

This has been mentioned in a previous thread, I see:

http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9392

It's hard to find any very useful information on the Eurocell site. I had a bit of a confusing conversation with one of their technical people, where I tried to explain that I wanted to understand whether they can offer something that will span a cavity under the sill and take the weight of a door/window installed above it. His answer seemed to be that this would never be an issue because the frame itself can simply span the cavity, but that's not what the window installers I've talked to have said. They always want a continuous solid base across the depth of the frame.

Anyway - they pointed me to here:

https://www.subframes.co.uk/cavity-closers/structural-door-packs/

And I'm making some enquiries with them. But I think that this system is not actually designed to be load bearing across the bottom horizontal member - it's more that you can fix directly into the jamb closers and they will transfer the load into the outer and inner leaves.

By the way regarding the above - the answer was very much that no, the bottom member is not supposed to be load bearing.]]> Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273089#Comment_273089 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273089#Comment_273089 Thu, 28 Mar 2019 14:28:29 +0000 lineweight Posted By: djhWell, you could fasten the compacfoam to whatever forms the edge of your timber floor structure. I presume there's some kind of perimeter beam. Might need to check the engineering - double up the beam or something in that area.

Sure...although in this case the floor joists are by default hung off the masonry.

It could be possible to change that, so that they sit on top of the masonry, with some sort of perimeter beam that compacfoam could be bolted into - but in any case the compacfoam could then sit directly onto the masonry wall, like the timbers. In this arrangement the compacfoam doesn't need to sit on top of insulation, so the bolting-through would become less critical.]]> Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273093#Comment_273093 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273093#Comment_273093 Thu, 28 Mar 2019 16:35:28 +0000 djh Posted By: lineweightthe compacfoam could then sit directly onto the masonry wall, like the timbers
If the masonry is wide enough to accomodate both, that sounds like an ideal solution.]]> Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273099#Comment_273099 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273099#Comment_273099 Thu, 28 Mar 2019 19:54:14 +0000 Nick Parsons Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273174#Comment_273174 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273174#Comment_273174 Thu, 04 Apr 2019 22:05:41 +0100 nstansbury
We went with Maxlight, a London company who we were very happy with, but their standard detail was to install onto a concrete upstand, which I point blank refused - and so my journey into insulated upstands commenced!

Internally, the floor is a flush finished 75mm polished concrete screed on top of 50mm K103 which is on top of the original slab. Isolating the polished concrete was a key criteria for me to preserve the thermal mass in the house, and so a huge thermal bridge in the rear of the house was just a flat out no.

I originally spec'd Marmox Thermoblocks, which both our SE and Marmox were happy with, however Maxlight's engineers were concerned about the bending moments not being restrained by the concrete pillars inside them, as each door panel was 230Kgs.

The SE and myself went through a number of options none very satisfactory, until we came across Armadillo's Armatherm. https://www.armatherm.co.uk/products/500-structural-thermal-break-material/

This is a structural insulation that comes pre-cut to size that is literally just bolted into the slab underneath. I actually thought I'd been sent the wrong product as it's so light and looks like a few lengths of 2x4 timber!

Super simple to drill through, fixed at 400 c/c with countersunk M8 bolts and then silicone sealed, standard DPC on top. Despite this non-standard detail the install team cracked on. They were concerned that as it was so soft that their fixings wouldn't hold, but found their M8 fixings of the track into the Armatherm were perfectly robust.

The team said actually was easier to install onto than a normal concrete upstand because it was dead flat & smooth, so easier to fix & seal.

Only downside - it's damn expensive stuff, but for the performance and ease of install it delivered what we wanted - YMMV.

Attached some pics from today and the original drawings I produced with Thermoblocks replaced with Armatherm

Cheers,

N]]> Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273175#Comment_273175 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273175#Comment_273175 Thu, 04 Apr 2019 22:09:55 +0100 nstansbury Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273176#Comment_273176 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273176#Comment_273176 Thu, 04 Apr 2019 22:10:03 +0100 nstansbury Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273177#Comment_273177 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273177#Comment_273177 Thu, 04 Apr 2019 22:11:14 +0100 nstansbury Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273180#Comment_273180 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273180#Comment_273180 Fri, 05 Apr 2019 00:08:12 +0100 lineweight Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273181#Comment_273181 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=273181#Comment_273181 Fri, 05 Apr 2019 00:52:26 +0100 nstansbury Cold bridge-free thresholds for heavy sliding/bifold doors http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=302958#Comment_302958 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16054&Focus=302958#Comment_302958 Thu, 24 Aug 2023 09:23:26 +0100 lineweight
Currently I'm looking at a Velfac door - not even a sliding one, just a regular hinged door so no load really goes onto the threshold. I asked the supplier how they normally deal with the threshold detail when fitted into a cavity wall and they sent me this not very helpful drawing.]]>