How to Pitch Gutters

The pitch of your gutters, or gutter slope or angle, is the most crucial element of any gutter installation. For most structures, the gutter pitch should be between ¼” and ½” for every ten feet of length. Learning how to calculate gutter slope is essential to ensure maximum protection from water damage to your home.

The correct gutter pitch is vital to allow water to flow freely and drain properly. Incorrect gutter pitch can result in pooling water, leaks, water damage, erosion, and insect infestation.

Some roof designs require the gutters to turn around corners or slope in two directions simultaneously. This is one reason expert installation is critical to your gutter’s performance. Establishing and maintaining the gutter pitch will help prevent overflows, clogs, and damage to the building.

Our guide is for homeowners interested in learning how to determine gutter pitch on their home the do-it-yourself way. You’ll follow three basic steps: determining the correct pitch, measuring correctly, and adjusting as needed.

Step 1: Determining the Ideal Gutter Pitch

Gutter pitch is essential for your gutter system’s optimal performance and efficiency. Fortunately, determining the ideal gutter pitch for your roof only requires a few tools and wearing the appropriate personal protective equipment (PPE) to keep you safe. 

Here are a few helpful tips for determining the ideal pitch for your gutters:

• Consider all of the factors that affect the gutter pitch, such as the gutters’ length, size, and style. The amount and frequency of rainfall the roof receives, and your aesthetic preferences should also be considered.
• Contact your local building codes office and ask about the regulations for the minimum or maximum gutter pitch allowed in your area. As mentioned earlier, the pitch will be ¼” to ½” drop for every 10 feet of horizontal run in most cases, but check before starting your project.
• Adjust the gutter pitch according to the design, such as increasing the pitch for longer or larger gutters or decreasing the pitch for lower rainfall areas.

Step 2: Measuring the Current Gutter Pitch

First, assess the condition of the fascia boards to confirm they are stable and will support the gutters effectively.

In many situations, the gutter pitch is correct, but the fascia boards have detached from the ends of the rafters. Make any necessary repairs to the fascia before measuring the current gutter pitch.

You’ll need a few tools to measure your current gutter pitch, like an arresting harness, a ladder, measuring tape, a marker (pencil is best), and a level (longer is better).

Here are a few more tips for measuring the current gutter pitch:

1. Secure your ladder safely at one end of the gutter run. Wear your arresting harness and use a ladder stabilizer to perform the work safely.
2. Place the level horizontally on the top edge of one end of the gutter section and raise or lower the level until the bubble is between the two lines. Mark where the level meets the fascia board with a pencil. 
3. Measure the total length of the gutter section from end to end. For simplicity, let’s assume the gutter section is 25’ long.
4. Move the ladder to the other end of the gutter run and repeat the process.
5. Measure the vertical distance from each mark on the fascia board from the bottom up. On the high end of the section, your mark may be very near the top edge of the fascia. On the lower end, the mark should be further from the shingles than the higher end, indicating a slope. Use a helper if needed to avoid leaning too far from the ladder.
6. Divide the total length of the section by 10 to get the drop per 10 feet of horizontal run. For example, if the gutter section is 25’ long, here’s what the math looks like: 

25/10 = 2.5

2.5 x ¼” = ⅝” 

The minimum gutter slope for the section would be about ⅝” from one end to the other. If the section is 50’ long, the gutter pitch would be double that of a 25’ long section, or about 1 ¼” from end to end.

Step 3: Adjusting the Gutter Pitch if Needed

Depending on your roof’s shape, size, and condition, you may need to make some minor adjustments to maintain the gutter pitch for its entire length. These adjustments will ensure superior performance of your gutters and make them look better.

You’ll need your harness, ladder, hammer or cordless drill, and new fasteners. If using gutter spikes or screws, avoid using the same hole as the old fastener. Make a new hole and caulk the old hole to prevent water intrusion. 

Here are a few techniques the pros use for adjusting gutter pitch:

• Thoroughly clean your gutters. Any dirt, granules, leaves, or twigs will add weight to the gutters, making them heavy and more challenging to adjust.
• Determine which end of the gutter is currently highest and begin there. Does the gutter slope from one end to the other, or is the high point in the center of the section?
• Loosen or remove any screws, hangers, or spikes that hold the gutter to the fascia for about 8’ to 10’ of horizontal length. Be careful not to remove so many fasteners that the gutter detaches entirely from the fascia. 
• Raise or lower the gutter until it reaches your desired pitch, and return the fasteners.
• Move on to the next 10 feet of length and repeat the process. Tighten or replace any fasteners.
• Test your adjusted gutter pitch with a level, or simply fill the gutters with a garden hose if any sections are slow to drain or hold water, re-adjusting the gutter pitch as needed. 

If your time or skills are limited, consider hiring a local gutter company to set the gutter pitch for you. They will have the tools and experience to do the job safely and as the manufacturer intended. Most will also provide a warranty and perhaps even a maintenance contract to take care of your gutters over the long term.

Calculating Gutter Slope the Right Way

Measuring your gutter slope accurately will help ensure the best performance your gutters should offer and extend their useful lifespan. Remember to determine the current pitch using the earlier tips, then measure and adjust the gutter slope as needed.

By maintaining the gutter pitch on your home, you’ll help prevent water damage, reduce your maintenance costs, and improve the curb appeal at the same time.

If your ladder-climbing days are behind you, contact our local gutter team. Request a free, no-obligation estimate to get your project started.