High-density polyethylene (HDPE) sheets are strong, lightweight, and waterproof plastic materials. They are very popular in construction and building projects because they last long, resist chemicals, and cost less than many other options. HDPE sheets help make buildings safer and more durable. Here are the top 10 ways people use them. 1. Vapor Barriers Under Slabs HDPE sheets work great as moisture barriers under concrete floors. They stop water vapor from coming up from the