How to Install Eave Troughs

Measure the length of the eave where the first run of eave trough will be installed. Divide the number of feet in the run by twenty. Eave troughs need to be sloped downward one inch for every twenty feet of run in the direction of the downspout. Tap a small nail into the fascia as near to the top of the eave as possible. Leave most of the nail exposed so that a string can be tied to it.

Tie the end of a chalk line string to the nail. Move to the other end of the run for the eave trough. Measure down from the top edge of the eave the number of inches that you computed in the previous step, and mark it with a pencil. Stretch the chalk line taut, and hold the end against the mark. Reach out 18 inches from the end of the line, lift the line 2 inches from the eave, and let it snap back. This will create a mark along the eave for you to follow when installing the eave trough.

Remove the chalk line from the nail, and pull the nail from the fascia. If you did not purchase eave trough with the end already attached, push an end covering onto the end of the eave trough that will begin your run. Make sure that it snaps firmly into place. Lift the first piece of eave trough up to the eave, and position the starting end with the top of the trough against the chalk line. Make certain that the top of the trough follows the line the entire length of the trough segment.

Slide the first eave trough nail through the tube nearest to the end of the segment, and tap it into the fascia with a hammer. Do not fully hammer the nail in. Move to the other end of the segment, and repeat the process with another nail at that end. Snap a connector onto the first segment. Lift the second segment into position and snap the end of it into the connector. Install the nails into the segment in the same way as the first segment. Continue this process until you are ready to install the last segment in the run.

Measure the remaining distance in the run. Cut a piece of eave trough with the downspout opening to the correct length with either a pair of snips or a hacksaw. Make the cut on the end opposite the downspout opening. Push another end covering onto the end of the eave trough that is nearest to the downspout.

Lift the final segment into position, snap it into the connector, and nail it in the same way as was done in previous steps. Move along the eave trough run, and tap all of the nails in tightly to secure the eave trough firmly to the eave of the building.

Lift a segment of the downspout tube into place over the nipple that protrudes from the eave trough. Use self-tapping screws, and insert them through the downspout and eave trough nipple on opposite sides from each other. Measure the distance to the ground from the lower end of the downspout segment. Subtract 6 inches from this measurement. Cut a piece of downspout this length. Slip the segment over the tapered end of the downspout segment already installed. Use two self-tapping screws to attach the segment.

Attach the downspout boot at the end of the downspout with self-tapping screws to divert the water away from the foundation of the house. Use two metal straps evenly spaced along the length of the downspout to secure it to the house. Wrap the strap over the top of the downspout, and insert a screw in each end that goes through the strap and into the house. If the downspout is still not completely stable, insert an additional screw through the strap and into the center of the downspout.

Apply caulk to the inside of the end covers and joints of the eave trough to prevent leaks. Install each additional run of eave trough around the house in the same way. If a run is more than 40 feet in length, you should slope the eave trough downward from the middle of the run in each direction with a downspout on each end.