[aerohead]

Originally Posted by jimsiggy

Coroplast is what I plan on using, but potentially I may use the 4'x8' sheets of the material you would line your shower with. I think it is cheaper and easier to get than coroplast. 1/16 in. x 4 ft. x 8 ft. Plastic Panel-63003 - The Home Depot

Take a hard look at that material before you buy.It may be so flimsy that no amount of short-span reinforcing structure behind it will be enough for it not to sag out of shape.