How to install gutters and downspouts
Gutters and downspouts direct rainwater away from buildings to keep foundations and basements from flooding. While installation isn’t difficult, most homeowners hire contractors to install gutters and downspouts or to replace them to be sure they work properly–and don’t leak. Whether you’re installing steel, aluminum or vinyl gutters, the home improvement tools and techniques are similar. Just follow this step-by-step approach to install gutters and downspouts that won’t leak.
How to install gutters
Determine where downspouts should be located to channel water away from the house. (A driveway is a good choice if the drive slopes away from the house.) Make a mark ½ inch down from the roof edge at the corner away from the downspout and one ½ inch down from the roof edge at the downspout. Use a string or laser level to be sure the marks are level.
Then, at the downspout end, make a second mark down ½ inch for every 10 feet of gutter in the run. For example, if the length from the corner to the downspout is 40 feet, the gutter should slope 2 inches (40 x ½) from the corner edge to the downspout. Place a tack screw at each end and snap a chalk line.
Drill pilot holes 6 inches from each end and then every 18 to 24 inches for the length of the gutter. The size of the hole will depend on the hangar type. If you are using hanger brackets, install them now.
Assemble the gutter at ground level. After laying out the gutter pieces, cut to length using a hacksaw or tin snips. (If using tin snips, cut the front and back sides of the gutter. Bend the gutter at the cut and finish the cut across the bottom.) Gutter sections are crimped at one end so sections will fit one inside the other. Join the gutter sections using seamers or slip-joint connectors to overlap the joints. If using slip-joint connectors, gently pry open the flanges inside the connector and slip the gutter into the flange. Then fold the lip over the front edge of the gutter. Apply a heavy bead of sealant at joints.
An alternate connection method is to overlap gutter sections 8 inches, fitting the upper gutter run into the lower run. Apply a row of 4 screws on each side. Seal with caulk.
Attach and seal end caps at the upper gutter end. If gutter run requires turning a corner, attach and seal inside or outside miter corners. Seal screw holes with caulk.
Turn gutter over, set downspout outlet in position, and trace inside of the outlet on the gutter. At the center of the outline, drill a ¼-inch hole. Then cut a hole for the downspout outlet with a hole saw or tin snips. Place outlet in the hole and caulk. If using an end drop, attach it to the gutter end the same way you attached gutter sections, then caulk.
Install the gutter. To use hidden hangers, insert the hanger into the gutter and nail hanger and gutter in place at pre-drilled pilot holes. To use spikes and ferrules, insert ferrule into the gutter and hammer spike through ferrule and gutter into the fascia board at the pilot holes. To use fascia brackets, install brackets into fascia board at pilot holes and snap the gutter into the brackets.
Attach elbow to downspout outlet, facing toward wall. Slip on a second elbow against the wall. If necessary, connect elbows with a short section of downspout to reach the wall. Set a third elbow at the base of the wall and measure the length of downspout needed to connect the elbows. Cut length from a section of downspout. Connect and caulk elbows and downspout. For metal downspouts and elbows, use needle-nose pliers to crimp the elbows. Attach downspout bands to the wall and lay in the downspout.
Once caulk and sealant have dried overnight, use a garden hose to assure water flows toward the downspout and to check for leaks.
—By Pam Sturgess
- Inside and outside corners
- Left and right end caps
- Joint connectors (seamers or slip joint)
- Stainless steel screws
- Downspout elbows, bands and extensions
- Tape measure
- Chalk line
- Drill with screwdriver bits or screwdriver
- Tin snips
- Caulking gun and silicon caulk
- Needle-nose pliers or crimping tool
- Ladder or scaffolding