Tue, 19 Dec 2023 06:26:24 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298724#Comment_298724 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298724#Comment_298724 Thu, 10 Nov 2022 15:23:00 +0000 revor http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298740#Comment_298740 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298740#Comment_298740 Thu, 10 Nov 2022 20:47:44 +0000 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298747#Comment_298747 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298747#Comment_298747 Fri, 11 Nov 2022 09:36:00 +0000 revor Posted By: djhHave you considered using grooved dry screed boards, or preformed insulation boards to hold the UFH with a dry screed over?

Sort of. Have used the preformed insulation boards on another bathroom (but do not think it is as good a job as if it was a screeded floor) but not dry screed boards. Was a bit awkward as well as not particularly flexible in routing pipe around sanitaryware to avoid potential problems with fixings. This is the last of my upstairs ufh install and would like to use up as much of the materials I already have, that is left over. i.e pipe, clips, tile backer board etc without buying extra materials if I can avoid it but at end of day not averse to any solution if needs must.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298749#Comment_298749 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298749#Comment_298749 Fri, 11 Nov 2022 10:13:41 +0000 TimSmall
I wouldn't use vermiculite - you want high thermal conductivity in the screed!

Cement in the screed was 85% GGBS and 15% OPC (because we had a few bags of GGBS spare - not essential by any means). "typical" screed sand:cement ratio.

We also used nylon screeding fibres to increase strength.

The mix was standard to wet consistency (but still used less water than a normal screed mix would, because of the super-plasticiser).

Most important ingredients are the polycarboxylate and the fibres.

Depth about 25mm I think (I can probably go and measure it if you're curious). It's been down for 9 years with no problems, and is now tiled over.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298752#Comment_298752 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298752#Comment_298752 Fri, 11 Nov 2022 14:45:18 +0000 revor Battens position to take fixings. Would do something similar with this next ensuite but floor span is greater so need to watch the weight, but if your 25 mm works well then, I think will be ok with that. I have 60 mm depth to work with to include the tiles in order to meet the 1st floor finished level so may get some extra insulation in there as well.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298756#Comment_298756 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298756#Comment_298756 Fri, 11 Nov 2022 15:52:45 +0000 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298759#Comment_298759 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298759#Comment_298759 Fri, 11 Nov 2022 19:17:23 +0000 revor Posted By: djhJust rereading the thread, I would guess the bath is the largest loads, when full of water and person. There's no need for UFH or a screed under the bath, I don't think? Which might reduce the concerns. Ditto for the shower stall. Personally, I'd keep the ensuite floor a few mm under the main floor level to prevent accidental runoff.

I would not do UFH under the bath nor any of the sanitaryware but would have screeded and tiled as easier to clean under. But I will rethink that as it would save work. I am not looking forward to carrying buckets of screed upstairs so not doing under the bath would help. Good point about leaving the ensuite floor a bit lower, an ensuite already in use is level and not been any issues with that but there is no bath in that one. In our previous house, our main bathroom had a reclaimed maple flooring on top of the original floor and in 30 years or so never had an issue with it and never had to revarnish it. Old houses never had the "sophisticated" materials we have today and if floor got wet you mopped it up. Sometimes think we use stuff because it available or its design appeals.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298764#Comment_298764 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17638&Focus=298764#Comment_298764 Fri, 11 Nov 2022 19:43:41 +0000 djh Posted By: revorI would not do UFH under the bath nor any of the sanitaryware but would have screeded and tiled as easier to clean under.Ah, you're planning a freestanding bath? We (chiefly SWMBO) won't have such a thing because of the extra cleaning required, so ours has a panel covering the visible side. BTW, SWMBO won't have tiles anywhere either, again because of the cleaning, so we have 'hospital' vinyl in the wteroom. A commercial installer did an excellent job. In a previous bathroom we used bamboo for the floor because it can handle water better than wood. All warmer underfoot than tiles, as well :)]]>