Did you insulate the floors?

Looks like the next big thing

Did the same in my victorian house. Did 100mm celotex between the joists. Love the UFH

@@SkillBuilder I did not personally do the work (just lived through it), looking back I feel probably more insulation could have been added. However the house floors were all just floorboards on raised joists, so not concrete that will conduct all the heat to earth. The pipe work was set into that concrete style board with the pre cut grooves. My guess is some heat does escape down, but it seems ultra effective, so I guess not that noticeable. Upstairs I am less bothered by potential leakage downward since it will only end up inside the house either way... the ceilings do not get hot and I have checked with a thermal imaging camera. What I like is the old house was never designed to have radiators, so they would have only looked out of place and get in the way... I will say it is not for the faint hearted ripping all the floors up adding all the infrastructure, which means raising the height of the floor by 3-4cm shaving all the door bottoms down then putting all the skirting board back etc. This was done in conjunction with a new oak hard floor. I avoided carpets as felt this may be too insulating. One other thing people always forget to mention is that once you have this done you cannot go filling your house up with furniture that is flush to the floor as this just traps the heat... it became obvious that furniture needed to have legs of a certain height that will allow the heat to flow round objects.

@@elslopez really helpful! Thanks for taking time to share! I would have never thought about the furniture issue!

Sounds great, was that a full wet system? We’d like to get rid of our carpet, like our neighbour, but her floors are freezing.

Tiles make no difference to energy used.

Did you go for the optional flux capacitor or leave it?

@@TheDankelsall Hi Dan, I did ask NHBC if there was anything else I could do back in 2002 but they said I still need ventilation and any heat recovery system simply would not be practical - so back to the future here we go:

I have the same- deliberately. When I installed the system, I realized the feeds (multi-system) and return ran under the bathroom floor. I did not insulate these (which modern regs require) and the result is a floor that is comfortable to bare feet. A feature that cost less than nothing!

@@Tensquaremetreworkshop My next house I'm doing that!

I am still trying to find some.

Damn straight!

Thank you so much 😀

Roger

@@eddjordan2399 ?

Jason always calls me Richard, it is his little joke, it amuses him and we would never want to come between a man and his entertainment.

@@SkillBuilder I really appreciate that Richard! Thanks mate.

I hope it wasn't concrete you used to cover the pipes.

@@SkillBuilder is screed OK, (I assume thats what he means)

@@SkillBuilder A cement based screed. Not exactly sure what it was (a company did that part of the job). They put a lot in. The floor takes roughly 4 hours to warm up fully. It's been down for 6 years with no issues.

@@SkillBuilder Dry screed. 4 - 1 sand, cement mix with some aggregate.

If you can get it but I have never found a supplier, it seems that it only goes out to big sites.

my understanding is, the closer the better, but direct contact is not always possible. Please if it is just the radiator water pipe against the floorboards then it still have air space around it, which creates ineffeciencies.

it is not an issue, it works well and you don't have to spend the rest of your life worrying about it. The mixer valve means the water does another tour or two.

@@SkillBuilder Thanks. Seriously though... I appreciate your work - you take us places we never go and I just chime in here and there; A bit of a PITA but really just food for thought. I'll throw some $ in your coffee mug after posting this. Just wanted to say thanks. Have a great break and lets see if next year is kinder... ;)

How much heat are you losing through the slab?

@@SkillBuilder None its insulated underneath cant be losing that much as ive had to set the blender valve to 45 and even my boiler stats at about 60 degrees. The slab heats up amazingly befor we tiled.

I would rather see pir board inbetween the battens. If you squash the mulitfoil you lose a lot

@@SkillBuilder what's the minium size pir board I could use as I only have 50mm to play with ..

Hi Robert The required insulation thickness is usually 100mm PIR but it is dependent on the perimeter so it can vary to get the U value. Depth plant for 120 mm if you can. The pipe is usually 16mm and the screed on top of insulation is usually 65mm but you can get pumped screed which will go down the 35mm so you get a faster warm up time. With the pipe at 200mm you should be able to heat the room easily enough but placing the pipe at 150mm gives you a more rapid warm up. If you are tiling make sure you leave an expansion gap around the perimeter and use flexible adhesive.

@@SkillBuilder Thanks for the detailed advice, much appreciated. Robert

They give you a hot head and cold feet. I would rather put them on the wall

Look at the systems which sit flush between your floor joists.

Generally you bring it on a little at a time by turning the blending valve down to 1 and then working upwards until you reach 4.

No but the insulation has to sit on something. What are you planning to do?

@@SkillBuilder renovation, old stone house. wacked in gravel in layers 70-100mm total depth, have allowed for 150mm insulation and 75 screed maybe incl mesh. Someone said sub floor so have put the job on hold. Would have to take out stone to get sub floor in.

Dümmste Antwort ever

@@thomasschafer7268 Ah, so you have cold feet on this matter.

@@Gordon.. I look forward to your KZfaq video explaining those issues. 😉 Do send me a link when you're ready.

I'd say the same about heat pumps, but I don't want to trigger Roger ;)

My parents had underfloor heating installed in their new build 68 years ago and I've never wanted anything else. Far higher level of comfort than convection radiators and very efficient.

stick it down with a polymer adhesive, it is amazing how well it sticks.

If you go to our home page and type in underfloor heating in the smaller search bar it will show you a few different systems. You can now get 22mm chipboard that is routed out to take the pipe, You still need the insulation but putting all the pipe above the joists has advantages. If you go for the pipe in tray method between the joists then I would notch the joists on the cross overs. Strictly it should not be too close to the ends but it is much easier than trying to drag the pipes through the holes. Going under is fraught with problems.

@@SkillBuilder thanks

What a great idea. That will be my next video

@@SkillBuilder 🤣🤣🧱👍🏽

What, they'd just stuck a radiator under the floor? Genius! :))

@@42RHD Yep 🤪🤣

@@SteveAndAlexBuild Hilarious!

Have you done this yet? What did you go for? The best method I see is to buy the insulation with foil either side. It's very firm so you cut with a saw to size and force in-between the joists to hold it in place. Personally I just used some garden netting, a Staple gun and a roll of fibreglass insulation but it was a bit of a hassle. I hope it's strong enough for over the years as well

@@PercyJackson93in the end I went for the overlay system downstairs from Ambiente (Ambisolo) and insulated between the joists underneath. I would have gone for something between the joists but we had a few sections (old house) of concrete floor that would have been too costly to dig out. Will do a between the joists the system upstairs. Happy Christmas!

I don't think you want a breathing floor. I think you need an effective vapour barrier.

@@SkillBuilder some of the kit companies just suggest a floor sealant. I meant thermal paint over the sealant. And thought with joists the vapour barrier was below the flooring surface, so for anyone laying over floor surface could use paint. Personally, on the solid floor option I would get in the scree router to cut channels to lay pipes flush, then a thin scree to even heat and lay flooring over. On joists, insulation between (if ground floor), then the ufh panels that bridge joists with a flooring layer attached on top.

Heat rises in air through convection but in a solid floor we are talking about conduction which is happy in any direction.

My underfloor heating (Nu-Heat) runs off a thermal store of 750ltr, if heating is needed the u/f water is pumped through a heat exchanger in the thermal store and the boiler only kicks in once the TS has dropped a significant amount. This then economically utilises the oil fired condensing boiler as it’s not cycling on and off constantly

@@davidianwalsh Thanks for the heads up.

@@davidianwalsh I'm looking at a similar setup with an oil boiler also, thanks for the info!

Hi Haken I have done a few jobs straight onto uninsulated concrete and there is no doubt you lose heat. The key thing is that the pipe is near the surface so you get a fast warm up time. This means you can turn it on and off at will but there is no thermal mass to even out the heat. I would love to do some tests to find out how much is being lost through the floor but it is hard to do. I will think about some test rigs but the bottom line is that people are willing to lose a fair bit of heat in order to get the warm floor. You are right about electric, it is crap.

@@SkillBuilder Thank you for fast response - need to do some thinking in the upcoming weeks, would be great if you could do some tests too - though appreciate it's not straightforward to quantify how much heat is being lost when uninsulated.

@@SkillBuilder I just spoke to a representative of an underfloor heating company - he told me that concrete is actually quite a good insulator in some cases (in my case particularly it's a flat on 1st floor - with flats above and below me) - and apparently the heat loss through concrete is only about 6-8% so not that bad. Am wondering what your thoughts are on that - as I cannot afford 10cm insulation, probably not even 3cm, best I could do is something like 1cm so am wondering if UFH in such case is something worth doing.

​@@SkillBuilder I have a holiday chalet with no gas. We installed electric UFH throughout, insulation between the joists (although that is nowhere near perfect, think badly fitting jigsaw puzzle), Amtico on top (7mm dual overlay board in between which acts like the screed in spreading the heat) with tile in bathrooms and carpet in bedroom. A really good stable comfortable temperature and very comparable on cost to run compared to other standard electric heating. We get lots of positive comments about it when people stay in the depths of winter. Yes,😅 it's expensive compared to gas but that wasn't an option. It's also cheap to install and no floor build up either. We did have to upgrade some electrics as we have 2x10kw showers so the power draw with 2 showers and the UFH is too much so it temporarily flicks off the UFH but that is constantly on and off anyway to avoid going past 27 degrees floor temp. It takes time to warm up from cold like traditional UFH so we just leave it on a target temperature of 21 between 7am and 10pm and the thermostats in each room do the rest. People over the road also installed it after seeing ours but cut corners. One thing we think makes a massive difference are these dual overlay boards - they just added cheap LVT on top of the electric mats. I think they looked at them and thought they were ridiculously expensive MDF but they do a great job at spreading the heat evenly

Take photographs of the heating at every stage. You can also request an invoice with the name of pipe manufacutrer because they give a very long guarantee on the pipe. When the boiler is signed off you will have a log book with the details of the installer and the readings taken of the flue emmissions. It should also be registered through the installers registration. They can do this with their phone.

Thanks for your response

There are many way of doing this job and it is certainly a DIY job if you follow the instructions.

yes it is very common to do that so it dries the shower out and prevents mould

@@SkillBuilder thanks. I need to think at any technical issue? Dilatation? Water tube distance away from main shower tubes?

I meant shower main drain pipe

Thank you

Absoloutely nothing, I really don't understand the video clips. If you watch the British Gas adverts it is the same, some guy pretending to fix something.

And why does he have a hard hat in a luxury bathroom? These stock footage producers really need to up their game. I can see why they liven up a video though.

Clearly he's confirming to a customer that this is in fact a towel rail and pointing to it it's position so as to avert any future confusion on the issue.

The cost of running it!

It is not really suited to heating a room to 21 deg. It is fine for tile warm up. My neighbour three doors down had it even though I advised him to have hydronic. He ran it for one winter and it was £1,000 for the kitchen and dining area only. After that he switched it off and put some radiators in.

Doing same work, but instead of installing wire, better to install pipes. Wire only works with direct electricity, pipes can have more options. You can heat pipes with stight electricity but later upgrade it to gas or heatpump also.

lol'd

The edit is not my job, it is way above my capabilities. I am merely the mouth on a stick.

@@SkillBuilder 'mouth on a stick' : That's the important bit.. keep going.

Yeah, I don't think those trees look very Surrey either.

I think you might be right about all that. Interesting ideas and Heat Geeks doing away with manifolds altogether which makes sense if you are running a boiler or heat pump at 50 deg C

Yep we have low build UFH across our ground floor (the EPS boards Roger was laying at 5:12), originally with a static mixer on the manifold and "dumb" smart controls on the (Vaillant) boiler constantly pumping out 70c flow temperatures relying on the manifold mixer to try and keep it down around 35-40c. We've now ditched the mixing valve on the manifold and swapped out the controls for Vaillant weather comp controls along with 2 Esbe electronic mixing valves managed by the Vaillant controls (installed by Andrew Millward, there's a video on his page of our install). That means we can run 2 separate weather compensated curves for the two heating circuits, one between about 20c and 40c for the UFH, the other that has a wider operating temperature range up to about 55c for the upstairs rads. As an aside Roger, I'm not sure low build UFH necessarily needs rads for quick response in most instances, because the pipes are right under the floor surface its warm within 20 minutes from the boiler coming on unlike conventional UFH, which raises room temps almost as quickly as rads in our case, even with ~30c flow temps.

@@LocostR1 nice 🤘 we're militant Viessmann disciples just like Andrew and I wouldn't entertain fitting ufh without an electronic mixer. Fixed temp seems absolutely absurd to me.

@@randomcamerajunk6977 If I knew 2 years ago what I knew now I probably would have had Andrew in to install a Veissmann with this kind of setup from the off, much better modulation from what I understand and the controls look far more logical and easy to use than Vaillant.

Thats just stupid argument. Need to have mixer with thermostats. How do you control different room temperatures seperatly if not using thermostat. Not very smart to constantly adjust flow speed manually from manifold.

No

Okay, Could you brief a little ?

No it doesnt you can get whats called a retro fit kit that goes on top of your current screed. It uses panels and the pipes click into it and then you fill the left over gaps with the filler that comes with the kit then put self leveling compound raises floor level by 22mm

@@leejames7964 But as Roger says, you will lose some heat through the ground. Much better to break up the existing concrete, dig down sufficiently to put 100mm of insulation, then lay your UFH pipes in a 50mm of concrete. It is disruptive,but it's worth it long-term.

This can be done equally as good using a high modulating gas boiler like a viessmann 200 and weather compensation sensor. They are 3x cheaper to buy and almost identical to run. Heat pump has the edge but takes 20 years to make the saving back.

@@handle1196 Yet to hear anyone come up with a gas boiler that produces less carbon output per kw of heat than a heat pump, that's where the real conversation is. The current energy & environmental crisis is not down to the cost of renewable energy or its carbon footprint it's a fossil fuel crisis. The solution is not more of the same problem. My point wasn't that heat pumps should be the answer to everything but surely a video talking about a low temperature heating system basically designed for a heat pump needs to at least acknowledge them.

@@barryferguson6219 i don't think anyone wouldnt want to go for the greener option, it just has to be more appealing than the fossil fuel option. Cost of living is through the roof and not just with energy if they drop them prices over night, so people will always choose the cheapest option. A heat pump needs to cost half as much to purchase i think.

Barry I actually did talk about heat pumps in this video and the fact that they don't work well if you switch them on and off but we cut it out because it was straying off the topic and a lot of people would see me as a stuck record. If you make videos for KZfaq it is always a job to keep them tight. Low temperature heating can be done with any heating appliance but a gas boiler is way more responsive to the great variations we get in temperature. The carbon issue is important but really we need better technology before we kick out gas. They are already warning of possible power cuts in January so the last thing we need is more people drawing off the National Grid.

There is nothing sensible about Heat pumps.

I am not sure that the 10% holds true for placing heating pipes on a cold concrete floor but I could be wrong

I'm not sure where this figure of 10% comes from? Urban myth more like and one that a few underfloor suppliers like to tell customers to get sales. I would say it is more like 20% heat loss through the floor when heating up an uninsulated slab. If anyone can come along with some science to say otherwise I'm all ears!

Apparently 80% of the heat lost through the slab is lost at the side wall footing. It's the reason that the footings are insulated all the way down when doing EWI properly.

What a load of tosh. You wouldn't have a vested interest in wood gasification boilers would you Keith Rimmer formerly of Ecopod biomass boilers I assume? :)

@@LocostR1 No mate I just changed the gas boiler to wood-fired and saved a fortune in gas bills in an old stone coach house with flag floors and draughty old leaded windows

You'd hope to save a bit on the gas bill with a wood fired boiler 👍

Ich stimme nicht zu, selbst mit Isolierung ist die Betonplatte kalt.