[Closed] underfloor heating ?

What flooring do you have/plan on putting back over?

Also, what is the construction and how well insulated is the existing subfloor? I'm guessing concrete?
You thinking of wet or dry?
Wet is best set into a screed, which would be around 75mm thick. This would also rely on having a very well insulated base. It can also be done with an overlay kit, (polypipe do a good one that is very good value) this is then covered with a liquid, laytex type screed, about 20-30mm thick.
The other alternative is electric. Again, you will need insulation, you can use thin boards with this and the overlay kit too. Cable or matting is layed over, then a liquid screed over the top to hold it all together and spread the heat properly.
I've fitted both types. Wet is cheaper to run if you use it often, but if it's an in screed type, takes a long time to heat up. Overlay kits warm up very quick.
Electric is easiest to live with, just turn on and off or use the timer. Gets warm fairly quick but can cost alot if used often.
Ideally you should cover with tiles. Pretty much nothing else is suitable for conservatories.

Concrete Subfloor, putting back laminate, dry. Not too concerned about new depth as the skirting all has to come off anyway.

Why nothing but tiles for conservatories ?

thanks for help btw 🙂

Installed my own last week - although it is part of an entire self build.

This is a 6x zone wet system from http://www.underfloorheating1.co.uk/home.php
500+m of 16mm pipe, laid in 75mm Isocrete K-screed above 100mm thin-R Xtratherm solid insulation. Allowing another 25mm ish for the tiles to finish height. So that's 200mm above concrete subfloor. If you dont insulate there's not much point to UFH.

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the manifold:
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the insulation:
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UFH being driven by a 700 litre thermal store.

I would say that with a laminate the effectiveness will be reduced somewhat - the laminate is an insulator so it isn't very good at convecting the heat from underfloor. Not to say it won't work, but it won't be as effective as tile and you will have to check it is compatible (ie doesn't warp with the heat).

FWIW, we used [url= http://www.discreteheat.co.uk/?gclid=CJiVyf3IsaICFVGX2AodbUvDTg ]Discrete Heat[/url] skirting rads in our sunroom as we didn't want wall-mounted radiators in the way. They seem to work well enough to me and the heat is straight into the room (but of course you don't get the nice underfloor warmth coming through).

WARNING!!! whatever you do, dont make the same mistake i did and try to heat a big room with electric underfloor heating!!!!(god knows what i was thinking) my electric bill during the winter is over £350 per month....i am having it replaced with some massive radiators, and hoepfully wont make that mistake again.....

Electric underfloor is OK so long as you only use it to take the edge off the coldness of the floor. My problem is that the stat control is tucked away behind the sofa next to a mains socket and one of our ferrets took a liking to the rubber of the stat adjuster and had a go at it, so for a few months over winter our floor was running at 23C which led to a rather hefty bill.

mmmm, V interesting.... Certainly sounds like a conservatory isn't the place to use electric underfloor heating. I guess whichever way we choose its going to be pricey though due to the lack of insulation from the plastic roof on the conservatory.

Fitting a wet underfloor heating system into only one room of a property isn't going to work very well if the rest of the building is heated with radiators.

That said retro fitting an electric system into a conservatory won't work well either.

I'm assumimg that you've removed the doors between the lounge and the conservatory. Why not fit larger rads in the lounge or think about a 'curtain' electric heater?

Heating an uninsulated conservatory, madness.

Mk1 explain why heating one room with underfloor won't work please?

Heated floors are nice but you should consider the overall heating system in the building to get most out of it. Some potential issues:
- the temperature adjustments are not as quick as with radiators (might not be problem in UK)
- not all floor materials can deal with heating, some wooden ones will loose the seams if heated too much
- heat will not stay in one place, if you have colder areas around the heat will be drawn from the floor

My current house does have heated floors only in tiled ares, I miss them quite a bit in the winter mornings...

Si, these guys http://www.ukunderfloorheating.co.uk/ are local and the boys who run it are part of the bolehills bmx track club and ride, They might be worth a call to see what they can advise?

The money might be better spent on a new roof.

Bear,

There are lots of reasons why retro fitting underfloor heating into one room won't work very well/effectively/efficiently.

I doubt the 'conservatory' floor is adequately insulated or if it is the insulation maynot be in the right place. If it's under a concrete floor slab then there is a huge thermal mass to heat before the room is heated. The flip side of this is the temperature of the room will be hard to control as when the heating gets turned off the stored heat in the slab will continue to discharge.

Extending a wet radiator system, I doubt the boiler would cope with (effectively) adding a large radiator say 3x4M in size.

Unless you plumbed it into the 'end' of the heating run you'd loose significant heat out of the system and thus the rest of the house would not be heated effectively.

The temperature of the water in an underfloor heating system is lower than that in a radiator.

So, to retro fit into a most likely poorly constructed conservatory a wet underfloor system would require a significant re-plumbing and electric control rewire and that's before you start thinking about floor levels, finishes and the thermal efficiencies of the rest of the conservatory structure.

As for an electric system. Well the struture details may make this very expensive to run. Where is the floor insulation fitted if at all. Is the floor level the same as the lounge?

Unfortunately, unless the OP can provide construction and material details of the conservatory then no one can advise as to what would be suitable. What they need is for a competant person to conduct a site survey and provide solutions that take into account the actual conditions on site.

Regardless of what heating they install, they will be contravening the Building Regs.

Mk1, you could correctly fit an underfloor heating system to a conservatory, or any single room for that matter. But you should never connect it to the radiator system for the reasons you stated. Providing you are providing a totally seperate zone for the heating to a conservatory then it is no problem. Insulation under the concrete slab could work providing you used the correct controls (did this in my own house) and you could take a lot of solar gain from the sunneier months in the autumn and spring.

Sorry, pet hate see, too many poorly installed underfloor installations, often many with no design being carried out. Was interested to hear why you thought they would not work as it was such a generalization.

crikey.. can of worms...

we just want to make the room a bit more usable when its nippy..

"mk1fan" what do you mean about building regs ? you mean you can't fit any type of heating to a conservatory ? would it require planning permission if you did ?

nickjb - Member
The money might be better spent on a new roof.

Can that be done with a "standard" Conservatory ? wouldn't the structure need to be stronger if a glass.. or better roof was installed ?

Bear,

I didn't say it couldn't be done. I said that it wouldn't work very well unless a substantial re-working of an existing system and potential extensive building works which I expect the OP doesn't/isn't/wasn't prepared to do.

However, as stated in my penultimate paragraph, the only way to determine what sensible options the OP would have is for an independant site survey by a competant and independant person.

For the record I have retro fitted an number of electric underfloor systems but only where the sub-structure could be adapted to enable the system to opperate properly.

simonm,

A conservatory is not a habitable room and is subject to lower minumum standards in the Building Regs. They should be closed off to habitable rooms and not heated.

What most people do is build the conservatory. Get it signed off by Building Control then remove the doors that separate it from the rest of the house. They then put heating in. Doing either of these turns the conservatory into a habitable room and thus make it subject to more stringent minimum standards of the Building Regs.

I wouldn't inform Building Control that you're intending on doing either of these - although legally you should - as you'll have potential expensive works to meet the Building Regs - not only the Part L requirements but also Part B could be tricky. However, be prepared for the issue to be raised when you come to sell the property.

Interesting stuff Mk1 and Stoner.

yeh, thanks for that MK1... V intresting, wonder if my Neighbour knows that who's is open to the rest of the house...

My Dad's a sparky and has done several large installations of the electric type - he was of the opinion they are expensive to run, a nightmare if there is a break on a long run (though it's unlikely) and aren't all that effective. People seem to want them for a clean look in barn conversions and the like, but end up with a few oil filled radiators from Argos come winter.

When were warned off either unless the whole house runs the system as you will never be able to get a constant temp between the rooms with rads and the room with underfloor.