The seed mats operate at temperatures well below the ignition point of wood. If you are still concerned, put a piece of styrofoam under it. My germination mats all have a 1/4 inch piece of styrofoam under them, for insulation purposes I suppose.

I've used a seed mat for over a year directly on an unfinished piece of plywood. We have had no problems. Jim

Thanks guys! Just didn't want all my work to go up in flames.

MollyD

Seed mats will be about 80F not hot enough to even start a fire on paper. The insulation is a good idea I use 1/2" Styrofoam under mine this puts the heat into the soil where you need it and not waste it trying to heat the air in the GH. I cut the foam board the same size as the mat that leaves room around the flats for air circulation.

I'm getting the idea that everyone is not talking about the same thing when I say "seed mat". Mine are not meant to go on or in soil. They sit under trays holding the seeds/seedlings.
Thanks!

MollyD

This is what I was talking about. You lay them under your flat and plug it into a 110V outlet.
here is the mats

Here is a link that might be useful: SEED MAT

Yes those are like mine.

MollyD

Posted by mollyd 4b (My Page) on Sun, Jan 14, 07 at 11:37

Yes those are like mine.
MollyD

Then lay a piece of foam under them to make them much more efficient and stop worrying about a fire it will be fine.