Basic diy under floor heating Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[cyclonebri1]

Hi guys, excuse a 1st time poster if this is in the wrong category please.

We are at present renovating an old police house for my daughter. Typically it will be a cold house although the extentions we are having built will be up to current standards.

All ground floors are dry solid concrete. but the big area which was once the old jailhouse, will form the base of the lounge so we want to ensure it is not a cold block.

The room concerned is about 7 mtr x 6mtr. We are about at the replastering/re ceiling/new upper deck stage, so more or less anything is possible but only if done quickly.

The bare minimum would be to add 25mm polystyrene insulation and overboard with 18mm high grade chipboard. The increase in height would be no issue. But I don't want to miss out on the possibility of adding a wet heating loop under the floor. The max additional height we can stand is 100mm.

So is it as simple as adding a 100mtr coil of plastic pipe on top of 50mm jablite or such, and 50mm of some sort of screed on top?. Manual or auto matic control needed of course.

I've tried th phrase this question in such a way that indicates I know my way round the diy game very well, but have never had any involvement with under floor heating other than the crappy basic electric stuff from such as wickes.

Any quick, cost effective help will be gratefully received :) :)

[acsimpson]

What floor surface are you planning on laying? I'm sure you know that underfloor heating isn't great with carpet or laminate floor where insulated underlay is typically used.

I don't have much experience of underfloor heating myself, other than advising you have to be very carefull where the pipe goes to avoid cold spots in the floor. You may have better results from insulating the walls and using the extra space under foot to put thicker insulation down.

[Perry525]

Your proposal will work, however, keep in mind tha heat will go down as well as up. Heat always moves towards cold.
You really need four inches of insulation below the hot pipe to save on energy cost.
Keep in mind that ufh will add a great deal of water to your system, this water needs to be heated before any heat gets into the room. So heating up and cooling down tend to be slow.
Ufh is best when used in an always on situation, very good as a background heat where people suffer from cold feet.
Not good for people who are in and out in a rush, unless you go for remote telephone contol, where you work far enough away from home to let it warm up before you arrive.
Do keep in mind the extra water and the extra cost - if you turn the system down or off.