How to Repair Gutters and Downspouts

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Gutters and downspouts are an important building system component to take rainwater from the roof down to the ground level without damaging the area around the house. Improper maintenance can cause large amounts of water to enter the structure at the roof

Proper gutter maintenance is an important aspect of any home improvement plan, especially when it comes to preventing roof and basement leaks which can lead to mold growth and wood rot. Performing minor gutter and downspout repairs will not only extend the life of the rainwater drainage system, but it can save you time and money in the long run by avoiding costly repairs to other parts of the building structure.

Rainwater Drainage System components


For most homes, gutters and downspouts should be inspected at least twice a year in the spring and fall.  The timing should coincide with seasonal rains and snowfalls.  Typically you should begin an inspection about a month before you expect any rainy or severe weather to allow enough time for repairs or replacement. Use caution when working on your roof or on a ladder. Be aware of the location of overhead power lines and utility feeds to the home.

Look for the following items:

  • Clogging
  • Loose hangers
  • Improper pitch
  • Low spots
  • Rust
  • Separated seams
  • Detached downspouts

Gutter Repairs


Improper drainage due to poor gutter pitch is the most common cause for drainage problems. Improper pitch causes water to accumulate in certain areas in the gutters, ultimately building up debris or overflowing the gutter.

The gutters on your home should be installed with a pitch of about ¼-inch for each 4 feet of gutter length.

You can use a string line and tape measure or a4-foot level to determine the slope of your gutters. Attach the string on one end of the gutter run and pull it tight to the other end cap; if possible hook it around the end of the gutter; sight down the length of the string to locate high or low spots. You can also pour a bucket of water into the gutter and observe the flow. If it runs off without leaving pools of water in the gutter, the gutter is set properly; conversely water will collect in the gutter at any low spot or obstruction.

In most cases the pitch of a gutter can be set in only one direction. However, gutter runs of more than 35 feet should slant in each direction from the center. With seamless gutters one length can be as long as the house. Older gutter sections may be capped at the center and have a separate run in either direction.

You can repair high or low spots in the gutter by bending the hanger than supports it. A slight bend up or down can often remove the low or high spot.

Some gutters are installed with spikes and ferrules. You may need to add an additional spike to raise or lower the fall of the gutter at any specific point. When spikes are used they can enlarge the hole in the wood fascia so it may be better to replace the spikes with long gutter screws. Before adding additional spikes or screws, drill a hole in the face of the gutter the same diameter of the fastener.

If your gutters are installed using hangers you may need to replace damaged ones if they become bent from heavy ice and snow or fallen tree limbs. There are two basic types of gutter hangers; a strap hanger and a bracket hanger. Strap hangers support the gutter with a piece of metal that wraps around the gutter and has a long strap that is nailed to the sheathing under the edge of the roof and shingled over. Bracket hangers are nailed or screwed to the fascia underneath the eaves of the roof.


When leaks occur, you may want to totally replace entire sections of the gutter rather than trying to mend them. However, small leaks and rust spots can easily be patched or mended especially at seams or corners.


Wood damage from leaking gutter seams

Aluminum and vinyl gutters will not develop holes unless they are damaged where steel gutters can rust and leak. If you have galvanized steel gutters you will have to remove any rust with a paint scraper or wire brush. A power drill with a power rotary brush removes rust quickly.

For small holes, apply a thick layer of sealant specially made for gutter repairs or you can use ordinary roofing cement.

For larger holes apply sealant around the hole and cover the area with strips of aluminum flashing cut to fit inside the gutter. Press the patch down tightly into the gutter with a block of wood or a large putty knife. Keep in mind the direction of the water flow when patching the gutter and make the high end of the patch as smooth as possible to prevent debris from collecting and forming a dam.

Downspout Repairs

Even a properly installed gutter system will not function unless all downspouts are in working order. Inspect your downspout system at the same time you inspecting and repairing your gutters.

Clogging usually will typically occur at the point where the downspout connects to the gutter or at an elbow. You can remove the elbows by removing the screw that connects it to the straight section of downspout. Where multiple elbows are installed to get around corners, clogging can be more common.

If your gutters collect falling leaves and debris, you should install leaf strainers in all downspout inlets inside the gutter. These strainers insert into the downspout outlet. The strainers allow water to flow but stop any leaves twigs from going down the downspout and getting stuck at a change in direction inside the elbow.

If you have a straight section of downspout that is clogged you can use a plumber's or electrician's snake to clean the downspout.

If the downspouts drain into an underground piping system you may need to remove the lower section of downspout and verify that the in-ground piping is clear. If it is clogged you may need to rent a drain cleaning machine or hire a professional drain cleaner to remove the blockage.

Most downspouts empty onto a splash block. Be sure these splash blocks are large enough and high enough to carry the water away from the foundation of the house.

Check the splash blocks occasionally to make sure they are not misaligned, damaged, or broken. Damaged splash blocks can dump gallons of water around the foundation which can flood basements or crawl spaces.

Additional lengths of downspout can be installed as long as the grade is sufficient to pitch it away from the foundation. It may be necessary to cut the downspout and reinstall the elbow at a higher point to create enough pitch for the new section.

Flip-up or roll-up downspout sections are available at hardware and home improvement stores that extend themselves when filled with water and retract when the flow of water ends.

You can add a new section of downspout to an elbow or another section by crimping the end of the aluminum with a pair of pliers to allow the new piece of downspout to slip inside the existing one.


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