New 12 zone install help for newbie!

[Luggsey]

Hi all, I'm building a new house to live in and want ufh throughout the ground floor.
It's concrete floors so I'm going to fit 100mm foil back insulation with membrane as usual, clipped ufh pipes back to 12 zone manifold.
Thermostat in each room back to manifold actuators.
Nothing unusual there, I just haven't done ufh before so would appreciate some helpful comments on:

Is there anything to choose between the brands, Wavin, JG Speedfit, etc.
I'm living in the house so will happily fit what's considered the best? (Subjective I know but if you are a full time installer you will know)

Zone sizes, do I keep a zone limited to say 100m of pipe? I know how to do the calculations for watts/m, pipe spacing for living area and conservatory and floor size but what's a general rule of thumb?

Do you treat every room as a zone? Example the hallway has a small wc off of it, do you zone that tiny area?

Finally when we screed on top will it make a huge difference if some areas are 100mm deep and some say 80mm deep, reason I ask is we have some unevenness in the concrete base, I'm trying to work out if we need to lightly screed it to make it totally level before the final screed?
So what's best, sand cement (with fibres whatever they are?) or get a contractor to pump in some sort of self levelling screed? I'm in North Devon so choice of contractor may be limited....

Loads of questions, sorry in advance, just trying to get clued up before lashing out 10k.

Merry Christmas all!

 

[Time's Ran Out]

Merry Xmas - you may have more replies if you post a similar thread in the Plumbers Forum.

 

[Dumbo]

Your ufh supplier should do all the calcs and layout plans . I know ours did . Screed wise I don' think u can beat a liquid screed in the situations . I know Mayhew easiscreed will go as far as Devon and their work is second to none .
I fitted my ufh in my house and I am a tiler ; it has nothing to do with tiling .

 

[Time's Ran Out]

More multi traders !

 

[Flintstone]

Get in touch with uheat, @Uheat - Jake he can advise well and offer you a good deal no doubt !

 

[Dumbo]

Some of our zones have 2 loops in but are controlled by 1 stat. If you use a pumped screed you can increase the thickness of your insulation and decrease the thickness of your screed .

 

[Chalker]

Most underfloor manufacturers will design the system for free. Just send the drawings, or sketch your own. With room sizes and heights, outside walls and any large glass areas.
They will ( if you buy their materials) give you full instructions and a Cad drawing to work from.
Screed for underfloor heating is best being a pumped type. This flows round the pipes better than a hand mixed.
100mm is way too deep for a quick heating response. Work to 55-65mm, by adding more insulation.
There's loads of good companies out there to supply like "Uheat. Uponor. Nu heat and wondafloor. I'm not a fan of polypipe , or speedfit especially for diy install, because the semi rigid nature of the pipe is difficult to hold down.
Ask the manufacturer if they can recommend a local installer. It's a fairly simple install, but can go wrong with layouts and filling.
We would charge for a days labour to fit most houses. Typically a ground floor on a 4 bed detached house would take take me and the apprentice about 6 hours to pipe up and pressure test.

 

[Luggsey]

Thanks for the pointers, I will is hep2o or Wavin a good choice, but I its easily available and looks easy to install?
I'm now sure the concrete sub floor needs to be spot on before starting so that's my start point followed by deciding on supplier.

 

[Chalker]

Wavin is ok, but it's Pex pipe. ( very stiff) polypipe manifolds are ok, but the mixing valves are rubbish. Polypipe has an online design tool to let you measure up yourself. But, boy it massively over estimates! Also they will sell you the plastic egg box panels. Theses are useless at getting enough pipe in a small room. Also most screed companies won't screed over it, as it likes to float up!
Obviously it's Christmas, so no one is open. Drawings take a few days. But every manufacturer has good stock.
I have an account with nu heat and wundafloor. If I order before 6pm, it's delivered before noon the next day.
Most are like that.
I've done so many that I don't get most designed. I know through experience weather to fit at 100, 150, or 200mm centres. And when to split rooms up into multiple loops.

 

[Luggsey]

Good pointers thank you.
Would you for example make a small wc off the hall a zone or pick it up off the hall?
If I zone every room on the ground floor and split the large areas into two zones I exceed 12 zones?
Have a look and tell me what you think?

 

[Luggsey]

I just realised that if I site the manifold in the 'cloaks' cupboard the amount of ufh pipes in the hall outside the cupboard will mean I would not be able to pipe that area as a zone?
In this case do I simply use the amount of pipes going to other zones in the hall to heat it?

I had initially thought to use radiators upstairs but is it feasible to wet ufh on top of a chipboard sub floor? I have seen insulation panels with the pipe route pre cut into them, does this stuff work well and who makes it?

 

[Chalker]

Without having sizes of rooms. But a quick look, I calculate you will need 15 loops. That's with combining your fall and wc. This will mean two manifolds. One in the hall and one in the cupboard in the dining room.
Rads on the first floor is always the best option. It heats and cools faster.