Hi I have a soil warming cable and thermostat that I used to have in a sand
box on a bench in my greenhouse. However it was very heavy and my bench
collapsed. So I thought I would update my bench and propagator and use the
soil warming cable to make a pad similar to this.

http://www.keengardener.co.uk/produc...cm-(42w).rails

So what type of material should I use to make the pad from? And how would I
fix the cable to the material? I suppose I could put it in the middle of
two layers and sew it in place with nylon fishing line but would that melt
with the heat?

I did try using a sheet of expanded polystyrene but the cable is melting
into it plus I used cable clips and they keep coming out of the polystyrene
and I am worried it might catch fire.

So any suggestions?
Thanks, Jenny