Why Gutters Overflow and How to Fix Them

You look out the window after a heavy rain and see your gutters overflowing, or you notice that the ground around your home is always muddy. These are signs that your gutters aren’t doing their job. Getting to the bottom of why gutters overflow is essential to maintaining the integrity of your home’s siding and foundation. 

We’ve compiled a list of the most common reasons that gutters overflow and practical tips on fixing common problems, including when to call a professional. 

Improperly Sized Gutters

Gutters come in several shapes and capacity levels; some are narrower than others, causing them to overflow. In some cases, gutters are wide and allow debris to enter too easily, causing blockages leading to overflow. Most homes use a standard 5-inch gutter slightly over 3 inches deep and 3 ½ inches wide. More oversized gutters are 6 inches wide and slightly over 4 inches deep. 

The size of your rain gutters plays a crucial role in handling the volume of water that runs off your roof during heavy rainfall. If they’re too small, they may quickly reach their capacity as water runs off shingles, roof valleys, and eaves, causing gutters to overflow. Wide gutters may drain well but catch debris that creates clogs, especially if trees overhang your roof.

How to Fix Gutter Size: If you or a professional have determined that your gutters are too narrow for your home’s roof pitch and square footage, it could be time for a gutter replacement. Professional gutter installation usually costs $800 to $2,480. If gutter replacement isn’t in the budget, a cost-saving fix could be to install more downspouts to help keep up with water drainage. Consult a pro when adding downspouts, as it can be an involved process. 

Clogs

At their simplest, gutters are channels that catch water and carry it to a downspout so it can drain harmlessly to the ground. When that channel is obstructed, you have a problem. Debris like dirt, leaves and twigs can clog gutters and stop water flow, causing water to run over gutter edges. When that happens, it can soak wood siding, underlayment, windows, the sides of your home, and brick mortar. Keeping gutters clear is the best way to prevent water damage. Regular maintenance and gutter cleaning at least twice a year is the best way to avoid clogs. 

How To Fix Clogged Gutters: If you can reach gutters with an extension ladder and are physically capable and confident in your ability to climb a ladder safely, this may be a job you can do yourself. You’ll need gloves, a bucket, and tongs to remove debris.

To clean gutters, follow these steps:

1. Lean your ladder against the side of your house but not against the gutter itself; you may damage it.
2. With gloved hands, scoop out any debris stuck in your gutter system and discard it in your bucket.
3. Once all the debris is removed, rinse any remaining dirt from your gutters and downspouts with a garden hose.

If you don’t want to scoop out all the debris by hand, use a leaf blower to blow out the leaves and twigs stuck in your gutter. 

While you’re up there, check gutters for holes, dents, and loose joints. Call a professional if you see extensive damage or if gutters are too high to reach safely.

If gutter cleaning is a problem, consider installing gutter guards to block debris from getting into gutters. Gutter guards are a good solution for gutters that easily clog and a home improvement project that most weekend warriors can tackle on their own.

Improperly Pitched Gutters

When gutters are working properly, they tilt ever so slightly to carry rainwater to downspouts. If your gutter isn’t set at the correct tilt or wasn’t installed correctly, the water won’t flow downward like it’s supposed to.

To ensure water is flowing properly through your gutter system, make sure they are set at the right pitch so water flows safely down the roof without damaging your landscaping or foundation. 

How to Fix Improperly Pitched Gutters: A flat gutter won’t drain; the water gets stuck in the gutter and eventually overflows. Check the pitch of your gutters. For every 10 feet, gutters should have a slope between ¼ inch and ⅛ inch. If it isn’t set at the right tilt, have your gutters inspected by a professional. Gutters can be checked for alignment, spacing, and downspout placement to determine if they are installed in a way that protects the exterior and foundation of your home. 

Damaged Gutters

Gutters endure a lot of abuse and can become damaged. A home’s gutters may have loose joints, broken seams, and holes due to sagging, misalignment, or poor stability. Extreme weather conditions, age, and poor maintenance are all factors that lead to gutter damage. A damaged gutter system can cause siding to discolor, brick to erode, and fascia boards to rot. 

How to Replace a Damaged Section of Gutter: Some gutter breaks, holes, or misalignments can be fixed on a budget. Small holes and cracks can be repaired with waterproof polyurethane caulks, composite putty or patches. You can adjust minor misalignments, dents, sagging, or bends on your own. And if an entire section of gutter needs to be replaced, you can probably do it yourself if you’re reasonably handy

Here is how to replace a damaged section:

1. Before you start, thoroughly clean out your gutters.
2. Mark both the highest point and the lowest point of your gutter with a nail so that you will know the correct pitch of the gutter when you install the new piece. Then wrap a string around one nailhead and wrap the other end of the string around the other nail. This will show you what the tilt of your gutters should be. You can mark the line with chalk and remove the string. 
3. Unscrew the old gutter with a screwdriver or cordless drill. 
4. Attach new fascia brackets to the fascia board. 
5. On the ground, cut a new segment of gutter to the right length.
6. Screw in the new gutter piece by securing it to the fascia brackets.
7. Apply sealant to each side to meld the new section with the old gutter system. The sealant will prevent the gutters from leaking. Let the sealant dry. 

Number of Downspouts and Splash Guards

The vertical pipes at the ends of your gutter system are called downspouts. They divert water from your home and foundation, draining it into wastewater or storm water systems or directing it into your yard. Typically a gutter system will have multiple downspouts, giving water many places to exit.

If overflow occurs, downspouts could be in the wrong position to drain water, or you may need more downspouts to direct water. Splash guards can prevent overflows by redirecting rushing water around the l-shaped edges of your home during heavy rain.

How to Fix Downspouts & Splash Guards: Checking for a downspout connection to your gutter is the first step in diagnosing the problem. Sometimes, your downspout may have shifted due to heavy wind or rain, causing a misalignment. Your local hardware store will have anchor screws and clips to help attach the downspout to your home’s exterior.

If you need more downspouts, it might be time to consult with a professional. Installing downspouts to an existing gutter system requires adapters and flange-seal components making it a complicated job. You can easily add splash guards to areas where gutters bend or curve with kits from home improvement stores. 

Frequently Asked Questions 

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Robin Chipman

Robin Chipman is a technical writer working toward her master's degree in Strategic Communication. She teaches QiGong in her community and enjoys exploring nature or sipping on a cup of herbal tea.

Posts by Robin Chipman