First, carefully measure the diameter of the hole, then cut the hole out of the sheathing.

Once the hole is cut be sure to then cut the insulation to make sure that the inspectors have good access to the piping underneath, be careful to reinstall the cut insulation before installing the plug.

The next step is to put the rubber plug into the hole and cover it with the outer placement ring. In the case of elbows, you may need to manually manipulate, and bend the ring for a better fit.

The ring is then held in place by the screws (provided upon request). Be sure to install the lanyard around the bottom screw so that the cap won’t get lost during an inspection.