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Do It Yourself


Create stronger, better-looking gutters by modifying standard gutter systems. Minimize joints; assemble strong, sleek-looking seams; and add roof flashing to keep water flowing into the gutters where it belongs.

Tools Required

  • Cordless drill

  • Crimper

  • Duckbill tin snips

  • Extension ladder

  • Hex head driver

  • Offset tin snips

  • Pop rivet gun

Materials Required

  • 1 1/4" self-tapping hex head screws

  • 1/4" hex head screws ('zippers')

  • 1/8-in. medium length rivets

  • Downspouts

  • Elbows

  • Gutter

  • Gutter flashing

  • Gutter hanging strap

  • Gutter sealant

Evaluate and Plan the Gutter Replacement Project

DIY gutter replacement can save you substantially over professionally installed gutters, but there are a few pitfalls to watch out for. Inspect the fascia and soffit (Fig. B, below) for signs of rotted wood, which must be replaced before you put up the rain gutters. Many houses have a trim board or crown molding nailed to the fascia just under the shingles. You’ll need to remove this, as we did, or add a continuous strip of wood under it to create a flat plane for the gutters. In either case, prime and paint bare wood before you hang the gutters.

Draw a Sketch and Measure Your House Before Installing Rain Gutters

Fig. A (below) shows an example of a rain gutter system for a typical house. Record the length of the rain gutter runs and mark the downspout locations. Then count up the inside and outside corners and end caps (note whether they are right or left ends). Measure the height of downspouts and add four feet to each for the extension away from the house at the bottom.

Each downspout requires three elbows. There are two types of elbows that turn either to the front or side of the downspout. Most installations require only front elbows, but occasionally you may need a side elbow, usually to turn the downspout extension sideways. Here are a few planning tips:

  • Locate downspouts in unobstructed areas where water can be directed away from the house. Avoid locations with obstacles like electric meters, hose bibs or sidewalks.

  • Place downspouts in inconspicuous locations if possible.

  • Install oversized 3×4-in. downspouts on gutters that drain large roof areas or if you live in an area with torrential rains.

  • Slope long gutter runs (40 feet or more) down both directions from the middle and put a downspout on each end.

  • Buy special roof hanger mounting straps for houses without fascia boards or for fascias that aren’t vertical.

Gutter Parts and Mounting Details

Measure the horizontal rain gutter runs and downspouts and identify the parts you’ll need.

Cutting the Gutter

  • It’s much easier to join sections on the ground than to work from the top of a ladder.

  • Instead of butting parts together and covering the joints with a seam cover as recommended by the manufacturer, lap all seams from two to four inches.

  • Cut the front and back sides with tin snips.

  • Bend the gutter and cut the bottom.

Notch the Gutter

  • Cut a two inch long notch in the front lip of the gutter with tin snips to join a rain gutter section with an inside or outside corner piece.

    • Pro tip: Cut a four inch long notch to overlap and splice together gutter sections.

Snap the Sections Together

  • Lay a bead of gutter sealant along the corner 1-1/2-in. back from the edge.

  • Hook the front lip of the corner over the notched section of gutter and snap it over the gutter.

Rivet the Sections

  • Join the gutter to the corner with six rivets in the locations shown.

  • Start by drilling a 1/8-in. hole (for 1/8-in. rivets) at the front of the gutter and installing the first rivet with the rivet gun.

  • Now drill the remaining holes and install the rivets.

Caulk the Seam

  • Caulk the seam on the inside of the rain gutter with gutter sealant.

  • Put a dab of sealant over each rivet.

Preassemble Before Installing Gutters

  • We’ve shown joining a gutter section to a corner.

  • Use the same process to join two sections of gutter, except overlap the pieces at least four inches.

  • When you’re splicing gutter sections, plan ahead to leave the best-looking factory-cut end on the outside if possible.

  • Also, lap the rain gutters so the inside section is facing downhill to prevent water from being forced out the seam.

  • Where a gutter ends, cut it to extend about an inch past the end of the fascia board to catch water from the overhanging shingles.

  • Then attach an end cap with rivets and seal the joint from the inside with gutter sealant.

Mark the Downspout Outlet

  • First, measure from the corner of the house to the center of your chosen downspout location.

  • Double-check for obstructions.

  • Transfer this dimension to the gutter and cut in a downspout outlet.

    • Pro tip: This method takes a few minutes longer than using one of the short gutter sections with a preinstalled outlet, but it eliminates two seams and looks much neater.

  • Mark the center of the downspout outlet on the bottom of the gutter.

  • Center the outlet, flange side down, over the mark and trace around the inside.

  • Cut a V-shaped notch with an old chisel as a starting hole for the tin snips.

  • Place two short scraps of 2x4 side by side under the gutter to support it while you chisel the notch.

Cut the Outlet Hole

  • Cut out the outlet hole with offset tin snips.

    • Pro tip: Red tin snips cut counterclockwise. Green snips cut clockwise. Either will work.

  • Cut 1/16-in. outside the line.

Rivet the Outlet in the Hole

  • Slip the outlet into the hole and pre-drill 1/8-in. holes for the rivets.

  • Remove the outlet and run a bead of gutter sealant around the opening.

  • Press the outlet into the caulked opening and install the rivets.

A Little Slope is All You Need

  • The number and size of downspouts determine how fast your gutters will empty.

  • Sloping them helps eliminate standing water that can cause corrosion and leak through the seams.

  • Slope each house gutter run down toward the downspout about 1/4-in. for every 10 feet of gutter.

  • If your fascia boards are level, you can use them as a reference for sloping the gutters.

  • Check this by holding a level against the bottom edge.

  • If they aren’t level, adjust the string line until a level aligned with it shows a slight slope.

  • Snap a chalk line to indicate the top of the gutter.

  • Then straighten gutter sections as you screw them to the fascia by aligning the top edge with the chalk line.

Mark the Gutter Slope

  • When installing gutters, set the proper slope by driving a nail 1/2-in. below the shingles on the high side of the gutter run.

  • Measure and record the distance from the bottom of the fascia board to this nail.

  • Subtract 1/4-in. for every 10 feet of gutter from this measurement and mark this distance at the low end of the gutter run.

  • Drive a nail at this mark and stretch a chalk line between the two nails.

  • Align a level with the string to check the slope. The bubble should be off-center toward the high side.

    • Pro tip: If it's not, adjust the string until the bubble indicates that you have the proper slope.

  • Finally, snap the string to mark a line on the fascia board.

Screw the Gutter to the Fascia

  • Drive 1-1/4-in. stainless steel hex head sheet metal screws through the back of the gutter into the fascia.

  • Install one screw every two feet.

Add Gutter Flashing

  • With gutter replacement, you can prevent water from running behind your gutters by installing a metal gutter apron flashing under the shingles and over the back edge of the gutter.

  • If your home center or hardware store doesn’t sell pre-bent flashing, ask an aluminum siding contractor or local sheet metal fabricator to bend some for you.

  • Ideally the flashing should be slid under the shingles and the roofing paper or ice and water barrier.

    • Pro tip: If this isn’t possible because the ice and water barrier is stuck to the sheathing, or there are too many nails and staples along the edge of the roofing paper, then just slip the flashing under the shingles.

    • Pro tip: If the flashing you’re using is too short to reach down over the back edge of the gutter, slip an additional strip of sheet metal flashing under the bent flashing and over the gutters.

  • Slide gutter flashing under the shingles and secure with one-inch roofing nails every two feet.

  • Lap sections about two inches.

Hook on Gutter Hanging Straps

  • With the gutters screwed to the fascia, it’s a simple job to install the hidden gutter hangers.

  • Install hangers every two feet to support the gutters and strengthen the front edge.

  • The hangers are designed to slip over the back edge of the gutter. But since we’ve covered this edge with flashing, just hold them level and drive the screws through the flashing and gutter back into the fascia.

    • Pro tip: The gutter apron will prevent you from slipping the hangers over the back edge of the gutter as intended.

  • The large screws included with the hangers we used are a little tricky to get started, especially through steel gutters and flashing.

  • Spin them at high speed without applying much pressure until the screw tip bites into the metal.

  • Then lean on the drill and drive them into the fascia.

Attach Elbows to the Downspout

  • We’re using standard 2x3-in. downspouts, but the procedure for oversized 3x4-in. ones is the same.

  • Assemble the elbows and downspout tube with the crimped ends facing down to prevent water from leaking out of the joints.

  • Use sheet metal screws rather than rivets so you can disassemble the downspouts to clean them if necessary.

    • Pro tip: Pros prefer pre painted 1/4-in. hex head screws with sharp points, called “zippers” because they’re easy to install. We found these screws in the aluminum siding section of a home center, but a gutter supplier would be another good source.

  • Screw an elbow to the downspout outlet.

  • Hold another elbow against the wall and measure between them.

  • Allow for a 1-1/2-in. overlap at each end.

  • Use a hacksaw to cut this length from the uncrimped end of a downspout tube.

  • You can cut downspout tubing with a 32-tooth hacksaw blade, but the pro we talked to uses a circular saw with a standard 24-tooth carbide blade.

    • Pro tip: A power miter box also works great for cutting gutters and downspouts. Use an old blade, though. Protect yourself from flying bits of metal with goggles, leather gloves, jeans and a long-sleeve shirt.

Crimp One End of the Downspout

  • Crimp one end of the short length of downspout with a special sheet metal crimper.

  • With the three blades on the inside of the tube, hold the crimper against the inside corner of the tube and squeeze.

  • Crimp three times across both long edges and twice on the narrow sides.

  • Attach this short section of downspout to the two elbows with two 1/4-in. hex head sheet metal screws into each joint.

Fasten Brackets to the Wall

  • Each length of gutter and every elbow is squeezed, or crimped, on one end to allow the pieces to fit together, one inside the other.

  • Since 10-ft. lengths of downspout are only crimped on one end, you’ll have to crimp one end of any cutoff piece to make it fit inside the next elbow or downspout section.

    • Pro tip: If you only have one or two downspouts to install, you can use a needle-nose pliers to twist crimps into the end. But an inexpensive crimping tool will save you tons of time and frustration.

  • Crimp one end of the short length of downspout with a special sheet metal crimper.

  • With the three blades on the inside of the tube, hold the crimper against the inside corner of the tube and squeeze.

  • Crimp three times across both long edges and twice on the narrow sides.

  • Attach this short section of downspout to the two elbows with two 1/4-in. hex head sheet metal screws into each joint.

Attach the Downspout to the Brackets

  • Finish the gutter job by attaching the downspouts to the wall.

    • Pro tip: If you can’t find U-shaped brackets, make them from sections of downspout. They look better than the bands that wrap around the outside and make it easier to hang the downspouts.

  • Drive screws through the brackets into the assembled downspout.

  • Complete the assembly by adding a length of downspout tube to the bottom elbow to direct water away from the foundation.

After Installing Gutters, Maintenance Is the Key to Long-Lasting Gutters

  • Clean leaves from your gutters twice a year, or hire a company that specializes in gutter cleaning and maintenance.

  • You’ll extend the life of your gutters and eliminate problems like backed-up gutters and plugged downspouts.

Buying Gutters

  • Standard colors are brown and white.

  • Matching inside and outside corners, downspout elbows and accessories are also available.

  • Buy special gutter sealant to seal the seams.

  • It’s available in small toothpaste-type tubes or 10-oz. caulk gun tubes.

  • Using many of the same basic techniques we show in this story, you can install your own “seamless” gutters.

  • Many seamless gutter companies will come to your house, measure and form continuous lengths of aluminum gutter to fit, and sell you all the installation accessories you’ll need.

  • It costs a little more, but you’ll be able to choose from dozens of colors and eliminate seams in the gutter runs.

  • You’ll also save the hassle of measuring, shopping and hauling the parts home in your VW bug.

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