patp Posted March 11, 2021 Share Posted March 11, 2021 We are all find and dandy with the installation of the UFH but a bit confused over the preparation side of it. Do we - Lay a plastic membrane first (tape all the joints) Followed by insulation (tape all the joints) Followed by another plastic membrane (tape all the joints) Followed by the UFH pipes? Do we need upstands of insulation and are they encased in DPM too? Our screed layer has sent us a diagram but he is mostly concerned that we tape all the joints. Have looked on you tube but most videos are about the pipe laying and not the preparation. Link to comment Share on other sites More sharing options...
ProDave Posted March 11, 2021 Share Posted March 11, 2021 Post the diagram you have and any information from e.g the architect about floor make up. There is no single answer, many ways to lay UFH. Link to comment Share on other sites More sharing options...
patp Posted March 11, 2021 Author Share Posted March 11, 2021 My technical skills for posting diagrams is zero We have just looked at the detailed plans and it seems to show that there is - a layer of dpm laid on the concrete slab.. Then there is a layer of insulation. Then there is a layer of dpm again. Then, we assume, the pipes go down. But surely this is not right? Should there be another layer of insulation for the ufh pipes to sit on? --------------------------------------------------------------------------------- The flow screed company has sent diagrams showing DPM Insulation DPM He is very keen on all joints being taped with the correct tape. He has not shown another layer of insulation. Do we need it in order to lay the ufh pipes? And does the screed then get poured over pipes and insulation? Link to comment Share on other sites More sharing options...
ProDave Posted March 11, 2021 Share Posted March 11, 2021 You need to get the detail right including enough insulation in the right places. with UFH is is more important than a normal floor to get plenty of insulation. Posting pictures on here is simple is is literally copy and paste them into a post. You must have some drawings from the designer? Link to comment Share on other sites More sharing options...
PeterW Posted March 11, 2021 Share Posted March 11, 2021 The second (top) DPM isn’t really a DPM. It is a slip membrane designed to stop the liquid screed flowing between the insulation blocks and floating them upward. Tape everything and then pin the pipes down, tbh this is why I prefer the plastic trays as nothing moves. 1 Link to comment Share on other sites More sharing options...
patp Posted March 11, 2021 Author Share Posted March 11, 2021 36 minutes ago, ProDave said: You need to get the detail right including enough insulation in the right places. with UFH is is more important than a normal floor to get plenty of insulation. Posting pictures on here is simple is is literally copy and paste them into a post. You must have some drawings from the designer? Easy if you have a smart phone etc. I just use a laptop. Link to comment Share on other sites More sharing options...
patp Posted March 11, 2021 Author Share Posted March 11, 2021 4 minutes ago, PeterW said: The second (top) DPM isn’t really a DPM. It is a slip membrane designed to stop the liquid screed flowing between the insulation blocks and floating them upward. Tape everything and then pin the pipes down, tbh this is why I prefer the plastic trays as nothing moves. Ah that makes sense. It is a large bungalow and the trays would cost us thousands Link to comment Share on other sites More sharing options...
ProDave Posted March 11, 2021 Share Posted March 11, 2021 2 minutes ago, patp said: Easy if you have a smart phone etc. I just use a laptop. Even easier on a laptop. Find the picture you want, highlight it, press Ctrl C or right click and press copy. Go to writing a post and press Ctrl V or right click and press Paste. Link to comment Share on other sites More sharing options...
PeterW Posted March 11, 2021 Share Posted March 11, 2021 18 minutes ago, patp said: Ah that makes sense. It is a large bungalow and the trays would cost us thousands ..??? how big are we talking ..?? They speed up the laying too so watch for savings elsewhere. Link to comment Share on other sites More sharing options...
patp Posted March 12, 2021 Author Share Posted March 12, 2021 12 hours ago, ProDave said: Even easier on a laptop. Find the picture you want, highlight it, press Ctrl C or right click and press copy. Go to writing a post and press Ctrl V or right click and press Paste. Not if you don't have the photo on there to start with Society nowadays does not allow for those of us who don't have the skills to take photos and load them onto computers. Neither does society allow for those of us who cannot accept texts with codes that release our money or give us access to all sorts of other financial dealings. Link to comment Share on other sites More sharing options...
patp Posted March 12, 2021 Author Share Posted March 12, 2021 12 hours ago, PeterW said: ..??? how big are we talking ..?? They speed up the laying too so watch for savings elsewhere. The bungalow is 180 sq m and we are doing the plumbing and heating which makes the labour free. Am I right, then, in thinking that we should lay the dpm followed by the insulation then another dpm with the heating pipes on top? Link to comment Share on other sites More sharing options...
Jilly Posted March 12, 2021 Share Posted March 12, 2021 9 minutes ago, patp said: Not if you don't have the photo on there to start with Society nowadays does not allow for those of us who don't have the skills to take photos and load them onto computers. Neither does society allow for those of us who cannot accept texts with codes that release our money or give us access to all sorts of other financial dealings. Get someone to show you after lockdown, its easy when you get the hang of it and very useful. Have you thought about upgrading to a smart phone? They are pretty cheap secondhand Link to comment Share on other sites More sharing options...
PeterW Posted March 12, 2021 Share Posted March 12, 2021 Not exactly but sort of correct...! Second top DPM can be a 300 gauge thin membrane as it’s only there to stop the screed going through under the insulation. If you’re clipping down then it’s DPM - Insulation - Slip Membrane - pipes Link to comment Share on other sites More sharing options...
Jilly Posted March 12, 2021 Share Posted March 12, 2021 (edited) Didn't I see something on tool share about the stapler thing which administers the clips to hold the pipes down? Edited March 12, 2021 by Jilly 1 Link to comment Share on other sites More sharing options...
patp Posted March 12, 2021 Author Share Posted March 12, 2021 2 minutes ago, Jilly said: Get someone to show you after lockdown, its easy when you get the hang of it and very useful. Have you thought about upgrading to a smart phone? They are pretty cheap secondhand We get no signal here so it would sit totally unused. 1 Link to comment Share on other sites More sharing options...
patp Posted March 12, 2021 Author Share Posted March 12, 2021 3 minutes ago, PeterW said: Not exactly but sort of correct...! Second top DPM can be a 300 gauge thin membrane as it’s only there to stop the screed going through under the insulation. If you’re clipping down then it’s DPM - Insulation - Slip Membrane - pipes Yay! Thank you Link to comment Share on other sites More sharing options...
ProDave Posted March 12, 2021 Share Posted March 12, 2021 @patp Do you have any drawings from the architect or designer? If you have them on your computer as some form of file pdf for example you can attach them to a post. At the moment I still don't know if you have a solid floor built up off the ground? Beam and block or timber suspended? What the designer has proposed as insulation, how much and where? Without this guessing where to put a membrane is meaningless. If you can't post a picture or file, then describe in words how your proposed floor is constructed and what layers it has starting from the ground upwards listing every single layer, what it is and how much. 1 Link to comment Share on other sites More sharing options...
dpmiller Posted March 12, 2021 Share Posted March 12, 2021 7 minutes ago, patp said: We get no signal here so it would sit totally unused. they do have wifi as well... Link to comment Share on other sites More sharing options...
patp Posted March 12, 2021 Author Share Posted March 12, 2021 Nothing like that on computer. We have huge paper drawings though! they show what has been described above. In words that is - A solid floor built up off the ground. Than it shows a layer of DPM followed by a layer of insulation, then a layer of membrane. The take off, that we had done by the builders merchant, shows this Polythene membrane Blue Standard Duty 300mu 100 M2 x 2 rolls Polythene Membrane Green tinted Standard 125mu 4 x 50m rolls x 1 Foil Faced Rigid PIR Insulation Board 2400 x 1200 x 20 mm x 4 Ready Mix Concrete 18 m3 Foil faced Rigid PIR Insulation Board 2400 x 1200 x 150 mm x 64 We have already laid one polythene membrane under the poured concrete floor. The walls have been built and the roof is on with windows due next week. Hope this helps. Link to comment Share on other sites More sharing options...
PeterW Posted March 12, 2021 Share Posted March 12, 2021 Ok I would use 1200 gauge below the insulation, 300 is very thin for a DPM. The 20mm is edge insulation. 150mm below is good for UFH. 1 Link to comment Share on other sites More sharing options...
Mr Punter Posted March 12, 2021 Share Posted March 12, 2021 16 minutes ago, PeterW said: Ok I would use 1200 gauge below the insulation, 300 is very thin for a DPM. The 20mm is edge insulation. 150mm below is good for UFH. The 300mu is 1200 gauge so will be fine for DPM. 125mu is 500 gauge and fine for the separation layer. 1 2 Link to comment Share on other sites More sharing options...
PeterW Posted March 12, 2021 Share Posted March 12, 2021 Sorry missed the mu and read gauge..!! Link to comment Share on other sites More sharing options...
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