Quote Originally Posted by bcr229 View Post
I don't see a problem with it as long as the heat is regulated by a thermostat.

Are you going to make the vertical supports adjustable from side to side? A big part of what makes back heat work is minimal air gap around the sides of the tub from front to back so the heat doesn't just escape around the tubs.
I wasn't gonna make the width adjustable. I may have to fill it with empty tubs and boxes to keep it full. I was gonna use a standard 3 foot wide plastic home Depot shelf.