How to Cut Rain Gutters: Tools, Steps, and Safety

Cutting rain gutters down to size.

Without gutters, rain can cause thousands of dollars in damage to a home, causing leaks in the basement, crawlspace, or foundation. Eventually, these leaks can lead to interior flooding, dangerous mold growth, cracks, and severe structural problems. Proper gutter installation is necessary to prevent damage, and cutting gutters down to size is part of the process to achieve the right fit.

Cut rain gutters by determining the length you’ll need and gathering the gutter sections, hardware, and desired cutting tool (i.e., hacksaw, tin snips, miter saw, etc.). Secure the gutter to a flat surface, mark the cut line, and slowly make the cut. Smooth rough edges with a file or sandpaper.

Though gutters are usually installed by professional contractors, many homeowners can cut them down to size and install them on their own with the right knowledge and tools. Read on to learn more about how to cut rain gutters and increase the performance of your home’s rainwater system.

1. Determine the Length of Gutters You’ll Need

Most gutters come in 4, 5, or 6-inch sizes, with 6-inch gutters holding significantly more water runoff than their smaller counterparts. Gutter sections typically come in 8- or 10-foot sections and are priced based on linear feet. You can expect to use around 150 to 200 feet of gutter length, based on the average home size.

Because gutters come in such large sections, you’ll need to cut several sections down to size, particularly when going around corners. However, first you’ll need to know the exact dimensions of your gutter space. You can determine this by measuring your home’s roof line and height or by measuring the length of your current gutter system.

2. Gather the Gutter Sections, Hardware, and Tools

Once you’ve obtained the dimensions of your home or the length of your current rain gutter system, you can purchase the length of gutters required. Additionally, you’ll need gutter accessories to complete the system, hardware, and a cutting tool to complete those necessary cuts to fit the gutters to your home.

Additional Gutter Pieces

To complete your entire gutter system, you’ll also need the following:

  • Corner pieces
  • Downspouts and elbows (you’ll need one elbow per 25 to 30 linear feet of gutter)
  • Drops
  • End caps
  • Seamers

Gutter Hardware and Other Supplies

For installation, you’ll have to obtain hardware and other supplies to join pieces together, seal joints, and secure the gutters to your home once you’ve cut the pieces down to size. Some of the hardware and other supplies you’ll need include:

  • Downspout fasteners (to fasten them to the house)
  • Gutter screws (for securing to the rafters through the fascias)
  • Mastic (to seal jointed pieces)
  • Sheet metal screws (for joining pieces of gutter together)

Gutter Cutting Tools

In addition to hardware, you’ll need special tools for cutting the gutters to size. There are several options for cutting gutters, as described below:

  • Hacksaw. With a hacksaw, you use physical force to grind the serrated teeth of the saw back and forth on the gutter material until it cuts through. It is ideal for flat cuts and can saw through most materials, including vinyl, wood, and thin aluminum. I recommend the LENOX Tools High-Tension Hacksaw on Amazon. It features a rubber handle and allows you to remain balanced and easily achieve high tension while making a cut.
  • Tin Snips. Metal cutters are the easiest tool to use when cutting gutters, but they can be time-consuming and cause bending or crinkling in metal. However, they’re very accurate as you maintain control. I recommend the Amazon Basics Straight Cut Aviation Snip, available on Amazon. These snips feature a serrated edge for efficient cutting and can easily cut through sheet aluminum and other materials.
  • Miter Saw – This is the fastest and most accurate tool, but it is also the most expensive. It can cut gutters to size within seconds and can penetrate a variety of materials. I recommend the DEWALT 12-Inch Miter Saw, available on Amazon. It features precise cross-cut capacity and offers fence support. You can get a compatible tungsten carbide blade (also on Amazon) for cutting aluminum gutters.

Note: If you’re cutting aluminum gutters, please see the section of this article entitled “Cutting Aluminum Gutters” for more helpful information.

3. Cut The Gutters to Size

Once you’ve obtained the gutters, hardware, and cutting tools, you can begin making your cuts.

Here’s a general overview of how to cut gutters, regardless of the material:

  1. Secure the gutter on a flat, level, stable surface. When using a hacksaw, clamp the gutter onto two sawhorses for best results.
  2. Measure the length of the gutter you’ll need. Mark the area where you’ll make your cut using a pencil.
  3. Put on protective gloves and eyewear. Dust and other small pieces may fly, even if you’re using a manual tool.
  4. Use a hacksaw, tin snips, or a miter saw to make the cut. Work slowly to cut as evenly as possible.
  5. Cut angles for corners. Ensure that all appropriate angles are cut as required (most corners on gutters are around 45 degrees; check your home’s dimensions to be sure).
  6. Repeat for all sections.

4. File Down Rough Edges

After making all necessary cuts, smooth down any rough edges. This is especially important if you’re using tin snips to make your cuts. Tin snips are notorious for creating jagged edges due to the number of cuts while opening and closing the blades.

For aluminum, copper, or steel gutters, you can file down the edges using a metal file. For wood gutters, you’ll need a wood file. For vinyl, you can use sandpaper to achieve a smooth edge.

Keeping edges smooth prevents injury when attaching end caps, sealing joints, joining pieces,  and moving the gutters around during installation.

Cutting Aluminum Gutters

You cut thin aluminum gutters in the same way as vinyl, copper, steel, wood, and other materials, but the main difference is that you need to have a steady hand and work slowly and carefully to avoid bending or crinkling the metal.

Hacksaws work relatively well on standard aluminum gutters, but tin snips don’t fare as well, though they can get the job done with a bit of extra effort. Heavy aluminum, however, is extremely difficult to cut through using traditional manual tools — tin snips simply won’t do it.

When working with heavy-rolled aluminum gutters, you can use a hacksaw, but you’ll have to work slowly and tirelessly to get through the metal. The material is very strong and durable, so it’ll take some time, especially when cutting multiple gutter sections.

If you use a hacksaw or tin snips to cut through dozens of sections of heavy-rolled aluminum gutters, chances are your hand will feel it by the end of the day. Not only that, but you’ll likely end up extremely frustrated with jagged edges and maybe even bent gutters.

If the thickness of the aluminum gutters is greater than .04 inches, I highly recommend the use of a power tool, such as a miter saw. This is not only for your sanity, but also for the sake of your hands. In fact, if you regularly cut aluminum gutters, a miter saw is a wise investment.

When using a miter saw on heavy-rolled aluminum gutters, do not use cheap alloy blades. These will not stand up to the durable aluminum; they will break, possibly leading to dangerous projectiles and potentially damaging the gutters. Stainless steel blades should also be avoided, as they create too much heat during the cutting process. Instead, opt for a fine-toothed tungsten carbide blade.

Tips and Safety Considerations for Cutting Rain Gutters

  • Measure twice, and cut once. Double (and even triple) checking your measurements could mean the difference between a perfect fit and finding out that you cut a piece too short, rendering it useless.
  • Always wear eye protection and gloves when cutting gutters. Pieces will break off, and they can fly into the air at incredible speeds. It’s also important that you work in a well-ventilated area and wear a mask when cutting or filing aluminum, as the dust can easily enter your airways.
  • Practice caution when working with sharp tools or power tools. If you’re unfamiliar with miter saws, do not operate one until you’ve educated yourself on how to use it. For more information on how to use a miter saw, check out this brief ten-minute video on YouTube:

Final Thoughts

Rain gutters are a critical part of any home. They stop water from cascading off the roof and forming an unwanted trough around the perimeter of your home. Otherwise, this trough would collect water and cause loads of problems in and around your house.

Installing rain gutters means cutting them down to size to ensure a proper fit and provide the best protection to ensure your home stays dry. It’s not difficult to cut gutters, but it’s important to know what you’re doing to maintain safety and ensure that you achieve the desired cut to avoid wasting time and money.

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