Installing gutter end caps on the ends of those gutters that do not turn corners is critical to both the function as well as the aesthetics of the overall gutter job. Without end caps, the water from rain will just drain out the end of the gutter, which defeats the purpose of having gutters in the first place. Here you will find the information needed to install the end caps.
Step 1 - Attach End Caps
With your gutters up, you will want to install an end cap on each corner that does not make a turn and connect with another gutter. You can attach the end caps with either galvanized screws and a drill or with pop rivets. If using screws, simply drill three screws in to each end cap, securing it to the gutter.
Step 2 - Attach Rivets
If using rivets (which both look and perform better than screws), drill a one eighth inch hole in the location of each rivet in the end cap. Secure the end cap with one screw, then pop rivets in the other holes. Remove the screw from the last hole and insert a rivet.
Step 3 - Seal
Seal the connection between the end cap and the gutter with caulk. This step should not be skipped; this is the only way to ensure a water tight seal.