UFH Q:

I've just installed UFH in our extension, it is great!

I just clipped it directly to the foam, using clips supplied. Screeded over with standard screed loaded with fibres to resist cracking.

We (my Wife) worked out on graph paper a suitable layout using the Bifolar layout rather than the traditional Meander pattern, as we felt that this would give more even distribution of heat and we managed to use all the pipe supplied, more or less equally on the two circuits.

Apart from the convenience of just pushing the pipe into notches,I cannot see any advantage in using 'egg crate'.

HTH Steve

In message , Tim.. writes

Couple of issues with *egg crate*.

Because each sheet links to the ones next door, you must avoid starting laying at two separate sites. Very tempting when you are doing more than one room with more than one pair of hands:-)

The other consideration is routeing several circuits from one manifold. The minimum spacing is 100mm so a 3 room system might have a run of 4 pipes going through a doorway/corridor but controlled by thermostats elsewhere.

regards

There's a lot to be said in terms of time saving to use rebar mesh and zip ties. The pipe is liable to want to go anywhere but where you want it to go :-(

John

Can't find anything on 'Bifolar ' layout - all web details seem to be meander. Can you give me a link please.

Rob

Do what I did. Put down some rebar grid and tie wrap it (loosely) to that.

Remember to pressurize while screeding.

How does that help?

John

It *doesn't* help to locate the pipe - but it *does* mean that any leaks will be apparent, and can be dealt with, *before* the pipe is buried in screed.

The bloke who did ours used strip templates rather than egg crates, and then clipped the pipe directly to the insulation. See

The stuff supplied with our UHF kit was about 1/4" thick, yellow stuff slitted along its length so you could part it for different slab thicknesses and with a polythene fringe to stop concrete getting behind it.

with plastic pipe., stops it from being crushed.

Well the first step is to pressure test the pipes for the above reasons.

the second is to maintain that pressure while screeding, as air filled plastic pipe will collapse.

Many thanks guys - this has been a useful thread. I'm planning a small self build conservatory for this year and this thread has a lot of useful info.

Harry talks about 100mm insulation - does it need to be as thick as this?

I'm sure when the weather gets more amenable to building, I'll be back with more questions. Rob

It does for UFH. less for ordinary. 50-75mm OK.

Ideally, if you've got room - but you can get away with 75mm.

We converted a built-in garage into a kitchen, so there was already a concrete slab which was only 150mm below the house floor level. We used

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember harry saying something like:

Or do it like so... url:

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember harry saying something like:

The url: prefix is simply honoured by more newsreaders.

Sorry my bad, it should have been BIFILAR, google "bifilar ufh layout" gives plenty of hits.

HTH Steve