Adam2 Posted February 21, 2019 Share Posted February 21, 2019 I'm looking at upper floor make up along these lines: 20mm tiles 70mm screed 50mm EPS with UFH attached 200mm concrete (in-situ or planks TBC) 100mm service void 12.5mm plasterboard If I put the UFH in the concrete (assuming in-situ concrete) looks like I would save 120mm in floor thickness at the cost of less insulation between floors. The main part of the house is 3 floors will be using ASHP for UFH and MVHR. Would appreciate thoughts on removal of EPS & screed : sensible or crazy ? or of course of there is a different make up I should be looking at. Thanks Link to comment Share on other sites More sharing options...
Mr Punter Posted February 21, 2019 Share Posted February 21, 2019 Concrete is heavy and expensive and that is a very deep makeup for residential. If it is deflection or sound insulation you are interested in, compare it with timber / engineered joist solutions. 15mm plasterboard is better than 12.5 as it is less likely to sag. 1 Link to comment Share on other sites More sharing options...
scottishjohn Posted February 21, 2019 Share Posted February 21, 2019 21 minutes ago, Adam2 said: I'm looking at upper floor make up along these lines: 20mm tiles 70mm screed 50mm EPS with UFH attached 200mm concrete (in-situ or planks TBC) 100mm service void 12.5mm plasterboard If I put the UFH in the concrete (assuming in-situ concrete) looks like I would save 120mm in floor thickness at the cost of less insulation between floors. The main part of the house is 3 floors will be using ASHP for UFH and MVHR. Would appreciate thoughts on removal of EPS & screed : sensible or crazy ? or of course of there is a different make up I should be looking at. Thanks If you want a solid upper floor ,and i,m not saying that is right or wrong --look at Isotex or Velox floor systems 1 Link to comment Share on other sites More sharing options...
Mr Punter Posted February 21, 2019 Share Posted February 21, 2019 46 minutes ago, Adam2 said: If I put the UFH in the concrete (assuming in-situ concrete) looks like I would save 120mm in floor thickness at the cost of less insulation between floors. The main part of the house is 3 floors will be using ASHP for UFH and MVHR. Would appreciate thoughts on removal of EPS & screed : sensible or crazy ? or of course of there is a different make up I should be looking at. This will make the UFH very slow to react. Also there will be heat lost to the ceiling below. The optimum concrete / screed or whatever is probably between 50 and 150mm, with a bit of insulation under to stop the heat going downwards. 1 Link to comment Share on other sites More sharing options...
Big Neil Posted February 21, 2019 Share Posted February 21, 2019 @Adam2, I myself like the idea of concrete because of the acoustic benefits, so i get why you would consider it. Not sure it it would fit your situation but have you considered the Thermofloor system from thermohouse. There are probably similar solutions. The thing that bothers me in terms of buildup which you wouldn't get with say posi joists, is the service void. Mind you, I guess it's swings and roundabouts. https://thermohouse.co.uk/thermofloor/ 1 Link to comment Share on other sites More sharing options...
AliG Posted February 21, 2019 Share Posted February 21, 2019 (edited) This is almost exactly the upper floor build up I have. Exactly as above, without the insulation your UFH will be trying to heat almost 300mm of concrete/screed and react extremely slowly. Ideally use liquid screed and keep the thickness down to 60-70mm, just above the minimum to cover your UFH pipes. This way the system reacts faster and you spend less on screed. You need the screed to put the UFH pipes into, to get rid of it you would need some kind of cast in situ floor, you can do that with the Thermofloor above but this is the kind of unusual way of doing things that builders don't like. Edited February 21, 2019 by AliG 1 Link to comment Share on other sites More sharing options...
Big Neil Posted February 21, 2019 Share Posted February 21, 2019 21 minutes ago, AliG said: kind of unusual way of doing things that builders don't like It's not for long that I had been considering such a floor makeup myself. Why would it be that contractors don't like such an arrangement? Link to comment Share on other sites More sharing options...
scottishjohn Posted February 21, 2019 Share Posted February 21, 2019 (edited) both the velox or Isotex floor system is hollow so you get some insulation and service voids see here forum.buildhub.org.uk/topic/7398-anybody-using-velox/?page=3 Edited February 21, 2019 by scottishjohn 1 Link to comment Share on other sites More sharing options...
Big Neil Posted February 21, 2019 Share Posted February 21, 2019 ahhhhhh - I'll take a look then, so it's integral to the system whereas with a system like that of Thermofloor of any concrete arrangement, you have to then put a substructure to be able to run those services and hang plasterboard? Link to comment Share on other sites More sharing options...
Adam2 Posted February 21, 2019 Author Share Posted February 21, 2019 31 minutes ago, Big Neil said: Thermofloor system from thermohouse Ahh that looks good. I was less interested in hollowcore planks due to the irregular floor areas and difficulties in delivery due to site access but these could be good - will research some more. Link to comment Share on other sites More sharing options...
Big Neil Posted February 21, 2019 Share Posted February 21, 2019 Some great instructional/technical videos on their site. Link to comment Share on other sites More sharing options...
scottishjohn Posted February 21, 2019 Share Posted February 21, 2019 7 minutes ago, Adam2 said: Ahh that looks good. I was less interested in hollowcore planks due to the irregular floor areas and difficulties in delivery due to site access but these could be good - will research some more. you cut velox or isotex with a saw Link to comment Share on other sites More sharing options...
AliG Posted February 21, 2019 Share Posted February 21, 2019 44 minutes ago, Big Neil said: It's not for long that I had been considering such a floor makeup myself. Why would it be that contractors don't like such an arrangement? Just that they like to always do things the same even if there is a better way, so will need some persuading. Your planned floor is just like mine and not unusual. Most larger builders will have some experience of concrete planks. They simply won't have experience with some of these suggested systems and often they don't want to learn. Link to comment Share on other sites More sharing options...
scottishjohn Posted February 21, 2019 Share Posted February 21, 2019 (edited) 3 minutes ago, AliG said: Just that they like to always do things the same even if there is a better way, so will need some persuading. Your planned floor is just like mine and not unusual. Most larger builders will have some experience of concrete planks. They simply won't have experience with some of these suggested systems and often they don't want to learn. don,t see any rocket scientists in the videos LOL downside is you need alot of acrow props --or small trees ,as it shows in a russian video Edited February 21, 2019 by scottishjohn Link to comment Share on other sites More sharing options...
scottishjohn Posted February 21, 2019 Share Posted February 21, 2019 (edited) hers another system for you econekt.co.uk/wp-content/uploads/2016/02/ECONEKT.-ICF-Elements-Brochure2.pdf see page 20 construction video of flooring www.youtube.com/watch?v=pdb5MqjSr9Q&index=16&list=PLIwx_CpmS37PPaGLSVS4fa6rEH1gcf5B1 Edited February 21, 2019 by scottishjohn 2 Link to comment Share on other sites More sharing options...
Big Neil Posted February 21, 2019 Share Posted February 21, 2019 I'll check out service voids later because I can't picture it other than fixing a load of maybe 30/100 timbers to the underside of a concrete floor one at a time. A polystyrene based system i suppose have mostly embedded supports for cross battening so is the same true with this method? Link to comment Share on other sites More sharing options...
scottishjohn Posted February 21, 2019 Share Posted February 21, 2019 1 minute ago, Big Neil said: I'll check out service voids later because I can't picture it other than fixing a load of maybe 30/100 timbers to the underside of a concrete floor one at a time. A polystyrene based system i suppose have mostly embedded supports for cross battening so is the same true with this method? ring the agents? econekt --in glasgow Link to comment Share on other sites More sharing options...
Adam2 Posted February 25, 2019 Author Share Posted February 25, 2019 Thermofloor looks like resulting in v thick floors. Have also seen Lewis Deck. Will ask my engineer about the combo of timber joists & ~50mm of concrete on steel planks re floor thickness. If anyone has used this would be good to know if any experience of the "feel" or soundproofing vs solid concrete. Link to comment Share on other sites More sharing options...
Big Neil Posted May 8, 2019 Share Posted May 8, 2019 I've been trying to find more out about this Lewis deck stuff. Any word? I have found nothing like it even. Link to comment Share on other sites More sharing options...
Conor Posted May 8, 2019 Share Posted May 8, 2019 (edited) What about decking system? I'm considering this as it'll tie in well with my ICF walls and internal supporting poured walls. Concrete volume is less than precast slabs, and no screed is required. I've played about with the calculator and a 160mm slab will cross my spans with the right reinforcement. Minimal propping required and deck serves as temp working platform. Allowing a 200mm void for the suspended ceiling, means a 360mm total floor build up. You can add mineral wool after services fitted for extra sound dampening. https://www.tatasteelconstruction.com/en_GB/Products/structural-buildings-and-bridges/Composite-floor-deck/Comflor®-60 One more thing, you use dovetail nuts in the channels for your service and ceiling hangers. Edited May 8, 2019 by Conor Link to comment Share on other sites More sharing options...
Adam2 Posted May 9, 2019 Author Share Posted May 9, 2019 17 hours ago, Conor said: and no screed is required My neighbour has used similar and was very happy as meant he could do a lot more work himself - though he also used EPS + EFH in a screed so still reasonably thick. What are you considering with this approach then for the floor make up? Tin + concrete (with mesh) + ? If no screed I understand that as meaning your finished floor is going on the concrete so no UFH I guess? Not sure how much thinner than pre-cast - mine is looking like 150mm precast the deck looks like it has min 60mm height + concrete on top which I didn't look into but presumably will be ~60 also depending on what span/mesh etc so not too much less than precast? My design is for pre-cast but I'm still interested in alternatives if there may be advantages. Link to comment Share on other sites More sharing options...
Conor Posted May 9, 2019 Share Posted May 9, 2019 1 hour ago, Adam2 said: What are you considering with this approach then for the floor make up? Tin + concrete (with mesh) + ? If no screed I understand that as meaning your finished floor is going on the concrete so no UFH I guess? Build up will be: steel deck panels, 12-14mm rebar, mesh, UFH loops (wet rooms only - passive house), C30 concrete, powerfloated. My thinking: 1. Panels are light and easy to handle and cut - we'll have a mezzanine and sunken bath- easier to cut to suit than precast 2. No crane required - safer working, panels can be manhandled then walked on. 3. No secondary screed - time, cost and labour saving. 4. Dovetail fittings and service voids will make fitting of service trays, ducting and suspended ceiling easier. 5. Easily meets and exceeds BC fire and noise requirements 6. DIY - I'm planning on doing as much as possible. 7. My walls will also be poured concrete (ICF and shuttered), will allow the whole lot to be tied in and form a very strong and thermally coherent monolithic structure. Also, with volumes of concrete I'll be ordering along pumps, floating etc, I'm hoping to get a good deal from local concrete firm. Some disadvantages: 1. No actual idea of cost yet! 2. Finished floor will require protecting during rest of build process 3. Floating of concrete to a surface suitable for finishing... may require power floating? 4. UFH will be slow to react... but pipes will be 35mm below surface and not required that often. I'm an engineer that works for a large consulting engineer firm... we're always trying to innovate and do things differently, to a higher standard and in a safer way. That's what our clients expect, and I'm carrying that philosophy through to my build. Link to comment Share on other sites More sharing options...
Adam2 Posted May 9, 2019 Author Share Posted May 9, 2019 Very interesting, the same angle I started from when initiating this thread - thinking of a deck / concrete system but went down the precast + EPS + screed route due to comments relating to downside of not insulating below the UFH. Like you, I figured why use EPS and then have another layer of screed as it involves a lot of cost and makes floors ~90mm thicker. As you say trade-off seems just to be heating reaction times for upper floors - though I notice you mentioned passive house so you'll have less of a requirement than I will I would expect. Will continue to ponder and will discuss with the structural engineer to see how much it may upset his calcs (+architect's detailed design/BR drawings) if we were to change. Link to comment Share on other sites More sharing options...
Big Neil Posted May 9, 2019 Share Posted May 9, 2019 (edited) that Lewis deck stuff if i've read correctly says as about an average of 50mm build up on top of joists. Seemed quite good to me. Then the normal rolling of insulation below. they reckon about £20 ish m2 for the corrugated deck and then the screed at circa £15, plus the insulation below of course, I was thinking of it as a replacement effectively for ply/chip and either spreader plates below or whatever buildup on top. Edited May 9, 2019 by Big Neil Link to comment Share on other sites More sharing options...
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