This floor is going to be the death of me!

My eMail to the Plummer today

Hi Mike,

Just when you solve one potential problem another rears it's head!

I was talking to polypipe about their heat spreader plate system (I'm a neard for the technical detail as you have probably gathered!).
They mentioned how important it is that for the system to work properly that the spreader plates are supported by the insulation board along their length.
This ensures good contact with the floor surface - any air gap at all apparently seriously reduces the efficiency of the system.

Polypipe advised the insulation needs to be fitted 18mm below the joist level and made as air tight as possible.
Currently the insulation is resting on battons which run across the bottom of the joists at 90 degrees.

So the insulation will need to come out and battons added to the joists to supoprt it at 18mm depth.
I'm gutted as I spent a weekend sealing the boards with foam and silicon!

I realise I'm hitting you with another issue and you haven't even put a foot on site yet, but its alot of money to be spend and it seems there is real potential for the UFH not to work as well as it should if it's not installed to the manufactorors instructions. I did mention to nick before he put the insulation in that the air gap between the top of the insulation board and the floor covering needed to be minimised, but I did not know enough about the system at the time to insist it was made 18mm. Hopefully adjusting the insulation won't a big deal.

What do you think?

Mike