here's what I'm doing.

First of all, you can see I've cut and attached the foam core board to both sides and the back of the tank to help retain humidity/heat.



Now here, you are looking at my screen from the top, and the side of the tape you see is the sticky side that is attached to the underside of the grating.

I've only covered about 80% of one HALF of the screen so far (you can't see the rest of it).



And THIS is the reverse side of the screen. This is the side that faces down into the tank, and you can clearly see I have the foil facing down. The snake has no way to gain access to the sticky side of the tape....



Is this ok/right?

How much room should I leave for air? I have been leaving about a 4 inch stretch of grate on the warm side open and covering the rest.