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underfloor heating


Gyn_Paul

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I'm in the fortunate position of starting renovating a house from the ground up. All the floors need attention of one sort or another and can stand raising by up to 6 inches, so I am thinking of 'wet' underfloor heating. Yes I know the capital cost is higher and I think I'm prepared to swallow that for a greater comfort level. Am I being daft or is there anyone who has gone this route already?

is it worth it?

how do the running costs compare with rads?

would you go back to them?

paul

 

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we put hot water underfloor heating in our house in Scotland and would never go back to conventional rads.

The house is constantly warm with no hot and cold areas.  We have found it cheaper to run as the the concrete acts as one massive storage heater and will give off heat for several hours after shutting down.

The fitting was very straight forward with all pipes running back to a manifold controlled by room stats and run with an oil fired boiler.

marcel

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Paul,

I am in the same position as yourself renovating groundfloor up and need new floor in the kitchen and lounge and I will be installing wet underfloor heating. I installed a small system in my conservatory in the UK. Absolutely brilliant, we have a 27m2 which is used all year round and no doors into the main house.

I used Polyplumb (http://www.polypipe.com/POLYPIPE/pp_html/main.html) as my supplier in the UK. They seem to be the only supplier who will sell individual items as opposed to all the other who want floor plans to "survey" before giving you a costing.

I know you need to work out thermal loss heat transfer etc but when was the last time an electrician or plumber worked out lumens or BTU's to install lights or radiators in a room?

Its not rocket science keep the pipes at 4" sorry 100mm centres and that will be sufficient for any room.

Bottom line do once you have you will never go back to radiators except maybe for towel rails.

Anyway good luck

John
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It is well worth it, cheaper to run, no ugly radiators or pipwork showing, no cold spots, silent running (no creaking), and with tiled floors cool in the summer and warm in the winter. Fab!

Yes it is an expensive purchase, but easy to do yourself; I would never go back.

S

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How I envy you. We have decided not to go down this route as the barn floor simply will not support the amount of weight needed. The floor is wooden and will need additional supports to stop the bouncing, we are not prepared to remove the whole floor (very large barn) and replace joists etc with concrete, simply far to expensive and our architect was a bit worried about the current weight (previous owner had put a skim of lightweight concrete filled with the 'balls' which has to come off as it is not stable).

The problem with changing old barns is that they were not designed for living in and our living area floor is not the 'ground floor'.

Hope it all goes well.

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Di,

We have wet underfloor heating here in our UK house, underneath a floating timber groundfloor and traditional wooden upper floor.  we've had no problems during the 6 years it has been installed, and wouldn't go back to radiators by choice now!  It's fantastically warm everywhere, and even though it doesn't work in the same way as concrete, you can still feel the warmth through carpet or vinyl flooring - and the cat absolutely loves it!!! We got ours through a company in Northern Ireland, can't remember the name, but could find it if you wanted.  They supplied everything (except the boiler) and it was a doddle to fit.  The idea was that it could be installed by a competent DIYer, although the instruction book was like a NASA manual, and the reality was much easier!

 

Marie

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We are planning to go the wet underfloor heating route. I've read several times now that if you have underfloor heating throughout the ground floor (we will) it's unnecessary to have it upstairs - just have a small top up radiator (of some description) in each room. I'm unconvinced... does anyone else have a view on this?
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We're about to have underfloor heating put into the ground floor of our old stone farmhouse & have been advised by our French plumber & architect to have conventional radiators put into rooms on the first floor. I'd be nervous about top up radiators only - better to go for the full heating solution in one hit rather than have to mess about later.  If fitted with thermostats you can always turn down the individual radiators if you need to.  We are in 32 and recent winters have been freezing so guess that's influenced my thinking.
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Underfloor heating is within the realms of a diy person long as you understand that it works at a far lower temperature than the rest of the system.It has its own circulating pump because of the greater resistance,temp control,stats,bypass or mixing valve and so on.Ignore these facts in your design and take it direct off the boiler heating circuits it will shorten the life of the coils and cause all manner of problems.In larger rooms you tend to put 2 3 or even 4 circuits to prevent cold spots and help cut down on resistance etc.Installing the coil is simple its the floor preparation which is important.[its not laid direct on to concrete screeds.]Always pressurise and test the circuits before screeding or tileing over.Trying to find a leak is embarrassing when the job is completed.Happy days.
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Thank you all for your thoughtful and positive replies. I'm convinced now it's the right road to go down. I've found a German company who manufacture a system of interlocking plastic 'trays' which sit directly on the insulation, you wind the coils of piping round the bumps (like tiny capstains) then bury it in screed. Quick to lay and set the pipes (apparently) and requiring a thinner layer of screed (less weight) and because its divided up into cells, the screed tends to crack less as it dries out (sounds fine in theory... I'll see if it lives up to the promises!).

Now all I have to decide is how to heat the water..... oil-fired, wood or geothermal heat-pump: with a hectaire of flat field outside the back door, I've certainly got enough land for it but not sure I want to be wedded to EDF even at the lowest Tempo rate, or if I can stomach all that mess and trench digging for the underground coils!

 

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Now all I have to decide is how to heat the water..... oil-fired, wood or geothermal heat-pump: with a hectaire of flat field outside the back door, I've certainly got enough land for it but not sure I want to be wedded to EDF even at the lowest Tempo rate, or if I can stomach all that mess and trench digging for the underground coils!

 

Perhaps this site can assist you in your decision - and No I have nothing to do with them.

http://www.avenir-energie.com/english/acceuil/frame.htm

 

 

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I'm putting underfloor heating in a house I'm restoring in the Var but have been advised not to use terracotta tiles on top - a real blow as these are inexpensive and made in all the surrounding villages, the options being much more expensive!
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[quote]I'm putting underfloor heating in a house I'm restoring in the Var but have been advised not to use terracotta tiles on top - a real blow as these are inexpensive and made in all the surrounding villa...[/quote]

That's surprising... Terracotta has much the same density, I should have thought, as concrete.

What did they say would be the problem with them ? (interested, as it is one of the possible finishes I was thinking of for the hallway)

paul

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Ive had underfloor heating for the last year and infact it's often a problem to cool the house down enough. With a baby in the house and having to keep it at 19/20C its the easiest form of heating to manage this and is exceeding it.

We used plumbbase for the purchase of our system but its a wirsbo system effectively. We bought the insulation from sheffield insulation are VASTLY cheaper than anywhere else and will give trade. The kingspan insulation was £700 from Wirsbo and we got it for £230. Just put this down, clip the clip rails in and run the pipes. We had a problem with the screed not being wet enough and drying too quickly which was a nightmare having talked to the screed engineer at wirsbo he said 70% of screeds aren't wet enough. We then tiled on top of the screed and had no problems at all.

Upstairs we have it under a wooden floor. We made sure our floor insulation would be sufficient and laid rockwool before laying the silver bubble insulation and then put the pipes down and floor ontop.

On the whole an excellent system and easy to run, We've got solars as well so didn't use an oil boiler but may do as the electricity immersion backup may prove too costly.
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