Part 3: Flash a Nail-Fin Window in a Wall with Zip System Sheathing

After the window is installed, it must be flashed, which is essentially the process of tying the window to the water-resistive barrier (WRB), and in this case the WRB is Zip System sheathing. If the rough-opening preparation is your last line of defense, the flashing tape or liquid flashing applied over the window nailing fin is the first line of defense. The flashing you choose must be a suitable product, properly applied, and continuous from the window, across the nail fin, and onto the surface of the Zip System. Here, builder Jake Bruton uses Zip System flashing tape, working in a specific sequence to ensure the layers of tape are able to shed water, and then rolling out each piece to ensure the bond is strong and long-lasting. Properly installed, and properly protected by trim and siding, this flashing becomes a strong first line of defense against leaks, rot, and window failure.