UFH in insulated raft foundation

[HanleeHouse]

Hi All, 

 

About to start our insulated raft foundation in the next 2 weeks. 

 

I have an urgent decision to make that I'd appreciate your input. 

 

We have 100mm of concrete above the EPS. The original plan was to use clip plates to attach the UFH pipe in, then use 50mm spacers and put the mesh. UFH company have advised that the pipes being 100mm below FFL is too low, and they would recommend putting the mesh in place (50mm spacers) then tie the UFH pipes above the mesh, meaning that there would be 25mm cover to the top of the pipe. 

What's your thoughts? Screed above isn't an option. 

 

Many Thanks

 

 

[JohnMo]

We have 100mm concrete above insulation and pipes are stapled to insulation. Slow response (but that is mostly down to 300mm pipe spacing), but that's fine. It gives a steady consistent house temperature.

 

You can charge floor on cheap rate, with excess PV energy via heat pump, no issues. You use it like a big storage heater. You can do straight Weather compensation.

 

Zones and setback times are a bit of waste of time, so keep it simple.

 

We have a sunny 10 Deg day, with 2 degs expected overnight. Plenty of excess PV today, floor charged up for free, heating done until tomorrow. No house over heating.

[Chanmenie]

screed above is a waste of money
 

Mines very similar to JohnMo except I have pipe spacing at 150mm.

I used EcFlow fibre reinforced concrete.

it heats up much quicker than I expected and I get away with low flow temps, highest flow temp I’ve had is 29 degrees. 

[HanleeHouse]

44 minutes ago, Chanmenie said:

screed above is a waste of money
 

Mines very similar to JohnMo except I have pipe spacing at 150mm.

I used EcFlow fibre reinforced concrete.

it heats up much quicker than I expected and I get away with low flow temps, highest flow temp I’ve had is 29 degrees. 

Hi @Chanmenie, is your concrete 100mm too? Did you staple to insulation or use clip tracks? 

 

[Chanmenie]

7 hours ago, HanleeHouse said:

Hi @Chanmenie, is your concrete 100mm too? Did you staple to insulation or use clip tracks? 

 

Yeah 100mm with pipes stapled to insulation. 
Spiral pattern with 150mm centres