Rack temperature above and below substrate

I am almost done with a new rack, I find that the temps are higher below the newspapers than on top. difference about 5 degrees. I know that it is the newspaper trapping the heat, because when I remove the newspaper, the temperature on the tub is the same as what it was on top of the newspaper. When I lay the paper down, it heats up further.

Now, it makes sense to make the tub temp 89F or so because some snakes burrow down. However, for me, some of them NEVER burrow, while some do. I know that I can go from 88 - 92F but given the higher levels are different from lower levels by a little this makes it more complicated.

If I make it so that it is 90F on the tub, and only 86F on the newspaper, is it ok that some of them will only have access to 86F? Those that never burrow?

UPDATE: With further testing, I find that the on top temp to be 90F, under the paper gets to 94.5! This is above what I want. So I basically have to choose between on top vs. below now.

If I remove the paper, it reads 90F on the bottom too, and considering when they burrow they lift the paper somewhat?

94 is a liiitle warm. I would shoot for 92 under the paper. If the snake is laying on the paper, it will probably let the heat pass through the paper to the snake. I find that my snakes move the substrate all the time. More often than not they are laying right on the plastic so it's good to make sure that spot doesn't get too hot.

Adjusting your rack can be a little tricky. I wouldn't worry too much about the temp difference above and below the substrate as long as you are getting a good hotspot below the substrate. If it was a thick layer of aspen or cypress mulch then I would be more concerned with the temp difference.

Hope this helps!

The only way I can make this 10 storey rack work is if the temp under substrate was 93.5 or so on the highest level, considering the lower ones are cooler. Is that ok?