Pro-Slope from the Noble Co. is designed with the Uniform Plumbing Code in mind. The UPC requires a slope of ¼-inch per foot to the drain under the waterproofing in shower receptors. Pro-Slope, the company says, creates the required slope.

Made from expanded polystyrene, Pro-Slope comes in a ready-to-use kit that includes a patented Positive Weep Protector.