How To Repair a Leaky Gutter

A leaky gutter can lead to serious problems, including damage to your home’s foundation, siding, and landscaping. Fortunately, fixing this common household issue is a relatively simple DIY project that most homeowners can tackle in an afternoon. In this article, we’ll explore the steps to repair a leaky gutter to protect your home from water damage. And, in the video above, This Old House general contractor Tom Silva shows his quick and easy method to fix the problem.

Common Causes of Gutter Leaks

Before you begin the repair, it’s important to identify the cause of the leak. Several factors can contribute to the issue.

Clogged Gutters

One of the most common causes of gutter leaks is debris buildup. When leaves, twigs, and other materials build up in your gutters, they can prevent proper water flow and create dams—forcing water to pour over the sides. This buildup also adds extra weight, which could make your gutters sag. 

Regular cleaning can prevent many leaks before they start. Tools you can use to clean out your gutters include gutter scoops, garden trowels, and leaf blowers with special attachments.

Improper Gutter Slope

Gutters need to be installed with a slight slope to direct water toward the downspouts. If the slope isn’t right, water pooling in the gutters can lead to overflow during heavy rains. Standing water increases the risk of rust and corrosion, and potential damage to the fascia board.

Damaged or Loose Gutter Sections

Over time, gutter sections can become damaged or loose because of extreme weather conditions, age and wear, or impact from falling branches or ladders. These issues can create gaps where water can leak out.

Tools and Materials Needed to Repair Gutter Leaks

Before starting your gutter repair project, gather the following tools and materials:

• Caulk gun
• Ladder
• Pressure-treated wood strips (3/8-inch thick x 3/4-inch wide x 8 feet long)
• Safety glasses
• Silicone caulk
• Table saw (if you need to rip wood strips)
• Work gloves

Steps To Repair a Leaky Gutter

Follow these steps to repair your leaky gutter.

1. Inspect and Clean the Gutter System

Begin by thoroughly inspecting your gutter system to pinpoint the exact location of the leak. It could be anywhere along the gutter line, including joints, corners, or seams. Once you find it, clean the gutter to stop debris from interfering with the repair.

Use a trowel or scoop to remove leaves and dirt and a garden hose to flush out fine debris. Make sure the gutter is completely dry before proceeding to avoid moisture interfering with the caulk.

2. Correcting the Gutter Slope

For water to drain correctly, the gutter must have a slight tilt toward the downspout. Use a level to check the pitch of your gutter. If the gutter is flat or sloping the wrong way, adjust it by loosening the hangers and re-securing them in the correct position.

3. Creating a Gap Between Drip Edge and Fascia

In the video, Silva identifies an issue with the drip edge being too close to the fascia board. To address this:

1. Cut pressure-treated wood strips to the proper lengths.
2. Carefully slide the strips behind the drip edge, creating around a 3/8-inch gap.
3. Check that the strips are securely in place along the entire length of the gutter.

This gap allows water to fall directly into the gutter instead of being drawn back toward the fascia board.

4. Applying Silicone Caulk

Once the gutter is in the correct position, do this to prevent water from seeping behind the gutter:

1. Load the silicone caulk tube into a caulk gun.
2. Apply a continuous bead of caulk along the joint between the top edge of the gutter and the fascia board.
3. Use your finger to smooth the caulk, and make sure the gap is completely covered.
4. Allow the caulk to dry according to the manufacturer’s instructions.

After the caulk dries, test the repair by running water through the gutter with a garden hose.

Preventing Future Gutter Leaks

Once you’ve repaired your leaky gutter, take these steps to prevent future issues.

Regular Maintenance

Implement a routine gutter maintenance schedule—clean gutters at least twice a year or more often if you have many trees near your home. Regularly check for loose hangers or damaged sections and tighten or replace them as needed.

Install Gutter Guards

Gutter guards can significantly reduce debris buildup, and you can choose a style that suits your home and local climate. While gutter guards can’t eliminate the need for maintenance, they can make cleaning easier and less frequent.

Address Underlying Issues

If leaks keep happening, investigate any underlying problems. Check your roof for damage that could be sending excess water into the gutter. Check that your downspouts are properly sized and positioned, and think about upgrading with flashing, drip edges, and downspout extenders if your current system can’t handle heavy rainfall.

When To Call a Professional for Your Gutter

While many gutter repairs are DIY-friendly, some situations may require help from a gutter contractor. We recommend hiring a pro if you have:

• Extensive damage to multiple sections of your gutters
• Issues with the roof or fascia board that are contributing to gutter problems
• A need for a complete gutter replacement or upgrade

If you’re unsure about tackling the repair yourself, it’s always best to consult with a professional gutter specialist. You can also read our guide for gutter repair pricing information.

Final Inspection

After completing your repair, do a final check to verify that all seams and joints are sealed. Run water through the gutter again to confirm there are no remaining leaks and that the gutter drains properly.