Electric UFH - Insulation

I want to lay electric UFH in a downstairs bathroom , I'm looking at Warmup [broken link removed] , HotFloors [broken link removed] and Elektra [broken link removed].

Does anyone have experience of these companies ?

The cost of 4sq meter of 10mm under-tile insulation board ( u 2.7 ) is +-€140-, this seems excessive to me, any comments?

pjq

what do you mean "u 2.7"... do you mean the thermal conductivity value is 0.027??
Personally i wouldnt scrimp on the standard of insulation board, have you enough room to incorporate 25mm insulation??.
You dont want to end up heating the concrete slab instead of the room with the dirtiest, most expensive heating source (electricity).

I contacted both hotfloor and warmup and both said 2.7 u for 10mm board , hotfloor have 12.5mm "Marmox " board with a u value of 2.16 .
Room is for a senior citizen so we dont want a step up also dont particularly want to rip out floor ( god knows when builder could do this !), I have already lined the exterior walls with 25mm insulation backed plaster board .
But looking at the building reg's of 0.45 [broken link removed] , my €140- of insulation is not looking good , it's about as effective as a double glazed window !
pjq

warmup uses an extruded polystyrene backed fcement board

hotfloor doesnt say what material their insuulation is, although it looks like a foam type...

assuming a 8 x 10 room... a 10mm board insulation (assuming TC value of 0.023, ie typical kingspan insulation) itself has a u-vlaue of 0.96 w/m2k.....

Their figures dont add up...
a u-value of 2.16 is roughly the same as a double glazed unit (as youve correctly pointed out)...... if they said 0.216 it would make more sense...

they must be quoting you incorrectly...
ask them what the thermal conductivity value of the insulation board is...... they should be quoting you values between 0.04 and 0.02

sydthebeat,

This is copy/paste of e-mail chat with Warmup;

You are now chatting with 'Lesley'
you: Hi Lesley ,
Lesley: Hello, how can I help?
you: I asked you yesterday , for U value of 10mm Insulation board ,you said 2.7 . My builder says it should be around 0.27 , did I mix it up ? What is thermal conductivity value ?
Lesley: The 10mm insulation boards have a U value of 2.7.
Lesley: The 50mm insulation boards have a U value of 0.54.
Lesley: This is measured in w/m3k.

pjq

very strange......
u values are measured in W/m2 K...... not W/m3 K....

If those are the manufacturers declared u values i wouldnt go near them.....
as i showed above a 10mm board of typical foam insulation has a u value of 0.96...
i cannot understand their figures. their must be very very little EPS in their boards......

have you recieved an info on Hot floors???

Spoke to builder this pm and agreed that floor has to go.
I didn't call hotfloor as they told me U2.7 yesterday . Maybe the strength needed to support the tiles has compromised the insulation properties of this product .

pjq

i would have though this myself, ........only, 10mm of concrete has a u value of 1.62 w/m2k...... figure that one out?????

i dont get their figures, there must be somthing im completely missing here....

anyway, if the floor is going.. change the construction to have more xtratherm or kingspan under the thinest screed possible....

We took out the floor this am , I'm still hoping someone has comments on the companies , Warmup , Hotfloor or Elektra .

pjq