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Great info thanks for the reply, helps a lot. I think this is the direction I will go as well

@Onoff I'm looking to do very similar to you, couple of quick questions. Why the EPS? Just to protect the DPM more? I'll be clipping my underfloor heating pipes to the insulation without the polypipe tray and then thinking just to lay the A142 mesh on top. Did you mix the concrete yourself or have it delivered? I need to do approx 110m2 (across 8 rooms so it can be split into smaller sections) and due to access and cost (truck would have to block the road) I'm looking to getting in a bunch of friends and doing it all with a mixer but still looking for advice on the correct mixture. Just a simple 1:2:4?

Thanks I actually didn't know that but it's my plan to have everything in ducting but I'll make double sure to make sure they don't touch now

After much deliberation I decided to go with the option of pulling everything out and properly insulating. The house is of two parts, new and old, the old has the wooden beams simply sat in the expanded clay to support the floor boards. Below the expanded clay (approx 300mm) is just a rubble. Here I intend to: -dig out all the expanded clay, -compact the layer of rubble with a whacker plate -50mm sand leveled and compacted with whacker plate -dpm -300mm EPS insulation (there will also be house wiring and plumbing laid into this) -ufh foil and underfloor heating pipes stapled to insulation -100mm cement screed (probably done by hand with a mixer, looking for advice on this cement type and make up) - finished floor, mixture of vinyl and tiles In the new part we are in the process of ripping out the old slab and will be the same idea but since we won't have so much depth here we will do 100mm PIR insulation to keep floor levels equal. Looking for advice if this is ok. Do I need another layer of concrete at the bottom? Or a thicker concrete layer or reinforcement or something? I'm worried over time the concrete layer will settle and crack and possible damage and break the underfloor heating pipes so not sure if I need a stronger layer on the bottom or a top screed over the concrete or something. Any advice would be greatly appreciated Thanks in advance

yeah you may be correct there Mr punter. Il be confirming this tomorrow hopefully

After some research it looks like it's foam glass under my floors. Now considering doing a limecrete floor. If I'm correct and the glass foam is ok I can remove the wooden beams, level out the glass foam, add a geotextile fabric and a grid for securing underfloor heating pipes, then lay the pipes and put something like 100-150mm limecrete on top. But just started the research on this so maybe totally wrong about that?

Thanks, sounds like an ideal base (and more expensive than I wanted 🤣).

Thanks for the info. As was lying in bed last night I was thinking that I would need a concrete slab under the insulation. So that would be digging out some of the old rubble, then: -sand blinding later -dpm -concrete slab (100mm??) -insulation -underfloor heating pipes and topped with anhydrite screed Or can I do without the concrete slab? This would be ideal, time and money are seriously tight so every penny and minute is valuable. Thanks again

Evening all Just started a completer renovation of an old building and need some advise on how to deal with the floor. Its a simple square building with a stone and concrete foundation base and after lifting a few floorboards it looks like it was infilled with a light, loose gravel or something and it has large wooden beams placed in the gravel. It looks like these are just sat into the gravel to support and provide a fixing for the floor boards. As far as i can see so far they are not connected to the walls or sat on anything other than the gravel. However after digging my hand down to the bottom of them at a few places it seems they are rotten. My plan is for a wet underfloor heating system and a laminate/viynl floor covering in most of the rooms and tiles or micro cement in another. Looking for advise on how to proceed. I was thinking of pulling out all the old beams, raking the fravel level, doing a blinding layer of sand (approx 50mm) compressed with a compacter machine, then a DPC layer. And then laying the underfloor heating and a anhydrite screed on top to cover pipes (50mm). But im new to this part of construction so not sure if this is right or totally wrong. I don't plan to lay extra insulation as the loose and light gravel sort of mixture I believe provides good insulation and we have at least a meter of it. however Im not sure how to fix the underfloor heating pipes as the normal clips would obviousley pierce the DPM layer so would I need the rails stck to the dpm or perhaps the castellated panels Any advice here would be very appreciated.

Yeah you are totally right. After doing all my calculations I found it was actually basically double this rate exactly like you said. I've planned all my pipe spacing to hopefully make balancing pretty easy. And thanks for the note on the expansion vessel I'll make sure to do that.

After Johnmo's feedback ive been away and done a load more research and calculations and looks like if I use 28mm copper the velocity and pressure drop will be comfortably within limits. Thanks for that Any feedback from anyone on anything else in the plan (positioning and types of valves etc). any problems you can see or things i'm missing or doing wrong? appreciate any feedback if you have it. Thanks again Colin

So i checked some stuff on this. Sorry i'm on learning curve here so apologies if i am say something stupid. The specs all say DN25 which i discovered is the nominal diameter which is different. im guessing this would be standard 28mm pipe (or possibly 35?). The connections to the in line anti freeze valve etc are g1". But I will try and confirm pipe size with the company soon. would 28mm (or 35mm) sound a better size? Flow rates: looking over my underfloor heating plans I added up the flow rate for each loop and came to a total of 10.2 l/m (i think this translates to 0.612m3/h). Does this sound right and do I need to add for DHW or anything else? Pressure drop: I did a pressure drop calculation using an online calculator based on a 28mm copper pipe (inside diameter 25.6mm), flow rate of 10.2 ltr/min, over a distance of 6m and a temperature of 40c and it gave me a result of 0.37096 Kpa or 0.00371 bar. My problem is i have not got far enough into my research to really know what this means or why its important but I will do some research. But does this sound ok?

thanks for the reply I haven't done that, I didnt really think there would be a problem here so I clearly need to do some researching on this. The outlet from the heat pump is 25mm and all the gubins they are quoting me with the heatpump (anti freexe valves, 3 way valves etc.) are 25mm which is why i went with that Yeah I know, the heat pump company are insistent on it for warranty reasons. I will at least use it as a volumiser and not buffer This was on the install drawing from the heat pump company so I just followed that. not necessary then?

Hi again all As i work through all the plans for my full renovation of the house im buying im now hoping to get some of your knowledgable feedback on my water plans. The house is an old house which will get a complete renovation and currently the house has nothing other than the mains mdpe coming in so I need to design and install and full system. Ive done a fair bit of basic plumbing but never on this scale and designing a full system so i have been trawling this forum to get tips and come up with a plan but im sure there are plenty of errors in this first draft. NOTE: Im sure all of my symbols that I made are not correct so apologies for that, hopefully they are close enough for you to see what I mean. I have gone here for the manifold system after seeing all the advice on this form. For simplicity I have opted to go without a HRC. The runs to the kitchen sink will be approx 6-7 metres from manifold (manifold next to UVC). The runs to bathroom will be approx similar. Most of the pipes will run under insulation on concrete floor ( I insulate pipes and cut slots out of bottom of PIR boards to acomodate pipes) Im doing this house in Slovakia and for some reason I cant seem to find the UVC multiblock valves here (with the balenced feed and tee for expansion vessel) so I will just put in a balancing valve separately (Or would a PRV suitable instead?) followed by a tee off for expansion with a safety valve. I hope it makes sence and i thank you in advance for any tips or criticisms you have, im sure there are plenty

Thanks very much for the help. I'll run some more numbers and scenarios using heatpunk and h2x to figure out the best spacing as you suggest