some insulation

The counter the problem of the burning wood, I bought a role of insulation material that is placed behind heaters to reflect heat and save energy.

Cutting the material is NOT done like this (as I found out the hard way)
Because the styrofoam on that side will break in tiny pieces and the reflective side will rip.

Instead, softly cut into the reflective side and break the styrofoam when everything is cut

After everything was cut, the insulation fit perfectly

And the insulation even works !

The heat is definitely reflected better and no wood burns (except maybe those small pieces that are exposed between the cut material)

Here's an interesting factoid though: the backside of the insulation material is made of styrofoam, which is expanded polystyrene. The very thing I want to melt with the oven ;)