Gutters: Strip Miters vs. Box Miters

miters kansas city

When it comes to owning your home, protecting all of its components from destruction and deterioration is a high priority. That’s why advancements in home remodeling tools, materials, and technologies have been such a huge focus for manufacturers and remodeling companies alike, with more innovations and improvements being studied, tested, and developed every year.

One often overlooked area of the home that certainly deserves more consideration is your gutter system. A gutter system is what lets the water run down the roof and away from the house to an allocated and appropriate spot. Without a functional and properly working gutter system, rainwater would run over your home and fall wherever it landed—seeping through your roofing materials, saturating the siding, collecting on window frames, and settling in pools around your front porch, deck, and landscaping.

A traditional gutter system is installed below the eaves of the roof and is meant to collect snow and rainwater, giving it a track to flow through and a safe place to run out. Despite the importance of a gutter system, most systems have weak points that can get clogged and become damaged by excess water over time. This is because gutters wrap around the house, creating joints where the pieces meet. Fortunately, homeowners can combat this to a degree with the use of miters.

Miters are to put it simply, the corners in the gutter systems. This extra piece is installed where the panels meet as an extra degree of protection against gutter failure. Depending on the type of gutter system you have and your own personal preferences, there are a couple of options to pursue with your team of contractors. In this article, our team at Smart Exteriors reveals more information about two of the most common miter options, which are strip miters and box miters.

What’s the Difference?

As we mentioned, the miters are what join two gutters together as they pass over a corner. The corner is where the greatest chance of leaks occurs. Before you decide which miter is best, it’s important to understand the basic differences between the two options.

  • Box Miters: Box miters are also known as pre-manufactured corners. They come in one single piece that is attached to the guttering runs. This option is easy to install. However, it does require sealing and fastening of two seams. One distinction that sets apart box miters from strip miters is that the joints and fasteners stick out and are more noticeable. As such, for those who are aesthetically minded, a box miter may be an unattractive option to pursue. In addition, there is a chance that the miter won’t fit due to an inability to customize the size.
  • Strip Miters: Compared to the box miter, this option offers a more seamless design. This translates to only needing to seal one side in comparison. Traditionally, the installers will utilize aluminum that has been bent to 90 degrees. In addition to the sealant, which prevents the risk of leakage, the use of rivets and screws are present to ensure the strip miter stays in place.

Installing Strip Miters

It’s true that rain gutters are susceptible to expansion and contraction due to changing temperatures. However, when installed properly, strip miters can help reduce the effects homeowners experience with this phenomenon. That’s why it’s important to understand the process of creating and then installing the strip miter.

Cutting Strip Miters for Gutters

  • Make sure the gutter machine is already loaded. When verified, jog the coil through until the end is located at the first run.
  • For a strip miter, you’ll want the gutter cut at a 45-degree angle.
  • While working, be sure to secure the miter to the back of the gutter only. By following this practice, you’ll ensure that the next piece of the gutter will fit easily into the miter. Until the entire process is complete, the goal is to maintain the ability to make adjustments without compromising the integrity of the gutter.

Installing Strip Miters

  • Once you’re ready to attach to the house, start by attaching the gutter that holds the strip miter to the building. Make sure the gutter slopes toward the downspout.
  • The next step is to attach the next gutter run to the building. Make sure the edge of the gutter is aligned to where the strip miter covers both equally.
  • Once everything is completed, secure the job by fastening the miter to the front and back of each gutter to ensure perfect sealing. In some cases, you may need to do this on the bottom as well.

Installing Box Miters

The good news is that there is no need to cut or create box miters since the product is already pre-formed. On the other hand, you will need to double-check that you have the right size miter and that it’s installed correctly, otherwise there’s no chance it will work to keep your gutter system secured.

  • When installing this miter option, you’ll want to connect it to the gutter with seamers or a slip joint connector for the most secure fit.
  • Just like a strip miter, this option requires the use of sealant. Unlike a strip miter, you’ll need to seal two or three seams depending on the cut. If this isn’t done, the chances for leakage rise exponentially.
  • Secure with screws and pop rivets to firmly attach the box miter to the gutter system.

Benefits and Cons

When it comes to the joints, the ultimate consideration is how well each miter protects against leaks. To that end, we’ve come up with some pros and cons of both options below.

Strip Miters


  • Only requires one seam, which minimizes the chances of leakage
  • Less chance of miter not fitting


  • Not as easy as box miter to install

Box Miters


  • Easy installation
  • No need to measure or cut


  • The pre-manufactured design may not fit all gutter systems
  • Multiple seams equal multiple chances of leaks

Making the Decision

At this point, you have a better idea of what you can accomplish with either option along with the pros and cons to consider for each. However, there are two specific situations to consider before choosing either one:

  • Is Your Gutter System Brand-New? Those with a new gutter system can benefit from box miters since the miters are pre-manufactured with today’s standards in mind.
  • Is Your Home Oddly Shaped? If your roofline is full of angles, corners, or other challenges, it’s recommended to stick to strip miters since they are more adaptable to modified gutter systems.

If you’re ready to explore your gutter system options, Smart Exteriors is here to help. Give us a call to speak with one of our expert home contractors about our exterior remodeling services for homes of all kinds, or our gutter guard systems and how they can complement your home’s gutter system. For a free, no-obligation pricing estimate for our services, fill out our online form to schedule an in-home visit now.