In message , Andy Burns
writes
Andrew wrote:

if this is a suspended and well ventilated ground floor, then in
your location, with only 25mm of EPS, you are going to lose quite a
lot of heat (and thus money) heating your underfloor space.

Given the 15mm(?) pipe is embedded in the EPS, there's only about 10mm
of insulation below the heating pipe.

This stuff does come in other thicknesses. I used 40mm but as you say
this still leaves less than 25mm of EPS below. Mine is on uninsulated
concrete:-( I don't think the OP has said.

Somebody with better maths than mine can explain *edge effect*.
Basically only the heat conducted into the floor near the walls is
totally lost.


--
Tim Lamb