Thickness of coroplast for underbelly enclosure?

Lynn, ten mm is about half an inch, so it is an approximation. If you ask me to show you with thumb and forefinger how much is ten mm, I have to think for a few seconds. Ask for a half inch, and there is no delay.

Someday, we will all convert to metric -- much more logical. But those of us raised on the old system find it hard to change.