Think of the Greenskin Envelope Seal as a plumbing boot for sidewalls, but without the metal base. It’s made from a 17-mil-thick polyethylene material and makes quick work of flashing pipe penetrations—just slip it over the pipe, slide building wrap under the bottom of the flange, then lap another layer of wrap over the top edge. Spacer buttons on the back of the flange allow for airflow. It’s available for pipe diameters from 1/2 inch to 4 inches for a suggested list price of $3.50 to $3.70. Mainline Backflow Products, 877.734.8691, backwatervalve.com
