Spacing query for underfloor heating between joist, 1st floor.

[zaqzaq]

Hi guys,

Looking for info on pipe spacing for upstairs wet underfloor heating between joists.
The joists are 8 inches wide and the ceilings 10ft high, Rooms 15 sqft . Should I have just one pipe running in between each joist or should I have the circuit running up and down in between each joist therefore having 2 heating elements in a 8 inch space or is one sufficient? I know its recommended that you space the pipes 200mm apart but are there any problems running them closer? I'm thinking of better warm up times etc??
Anybody come across this before?

Regards,

 

[EPH]

Speak to the manufacturers

 

[Rybo_1]

Joists are only 8 inches apart? Did you mean 18 inches?

 

[Nostrum]

Pipe spacing depends on heat loss of room and flow temperature of circuit.

 

[Ermintrude]

You wound struggle to bend pipe into a return between them. You could go lefts all the way across the room and rights Al the way back. Left side of joist then rights on way back. U using biscuit mix ?

 

[snowhead]

Pipe spacing depends on heat loss of room and flow temperature of circuit.

And diameter of pipe.

 

[zaqzaq]

Hi Guys,

16mm pipe, biscuit mix for the screed. I did read that the min diameter for a 180 at the top is 90mm Screed 45mm depth?
Can you elaborate on heat loss? It's for a 1st floor (downstairs already complete, separate apartment)
Many any difference?

 

[Ermintrude]

45mm? 25mm! On 100mm celotex.

 

[Chalked]

Hi Guys,

16mm pipe, biscuit mix for the screed. I did read that the min diameter for a 180 at the top is 90mm Screed 45mm depth?
Can you elaborate on heat loss? It's for a 1st floor (downstairs already complete, separate apartment)
Many any difference?

underfloor is not just a matter of seeing how much pipe you can get in. Whatever manufacturer or system you go with, I would recommend that it is professionally designed.

 

[tamz]

All the manufacturers will design the system for you for free (well i've never paid).
Tbh, even though i know how, i wouldn't design it myself. If there are any comebacks its not my rse getting bitten.

 

[zaqzaq]

Sorry Ermintrude, Not sure what your getting at.
Just to be clear I like to understand whats going on I'm my home when I'm renovating at this site and others helps me out to understand what I'm paying for. If you see a problem can you explain. Im not going into business here just want to understand.

Plan for 1st floor between joists,
Ply on batons between joists,
50mm insulation rigid board,
16mm pipes
45mm biscuit screed.
If I'm making any big mistake please let me know!
Thanks.

 

[Gray0689]

Go 150 mm spacing and you will be grand
But get manufacture to spec how many zones and how many branches on manifold

 

[Ermintrude]

No need for 45mm 25 fine. Next is ply- no need if u use thick insulation