How to Cut Angles on a Seamless Gutter

the corner of a seamless metal gutter with supporting brackets
  • 5-10 hours
  • Intermediate
  • 1,000-2,000
What You'll Need
Measuring tape
A bench or sawhorse
Old towels or carpeting
Fine toothed hand saw
Miter saw (optional)
Seamless gutters

Installing a seamless gutter on your house can be a bit challenging, but will also be a very useful and satisfying project. Rain gutters protect many important things in your home. They stop water from running down the walls of your house and also keep water from collecting and running down windows and on top of doorways.

Rain gutters also run water well away from the foundation of your house. Over time this collection of water could compromise the integrity of both your walls and the foundation of your house. It is important that you do not have leaks in the run of your rain gutters. The main place these leaks can occur is along with angle cuts for making corners with your rain gutter.

Step 1 - Measure Carefully and Determine Angles

The 90 degree turns that must be made by your seamless gutters to go around the corners of your house are accomplished by attaching to pieces of gutter at the corner that are both cuts at 45-degree angles in relation to each other. The cuts for these angles must be the measurement to both the inside of the angle and the outside corner of the angle where the two gutter runs must meet.

Keep in mind that the measurement of the outside edge of the gutter runs along each wall will be longer than the measurement of the inside edge. If you confuse these measurements you may come up short with your gutter lengths and have to discard a large expensive piece of aluminum because of it.

Step 2 - Prepare a Proper Working Surface

It is very important to create a proper surface on which to cut your aluminum seamless gutter. Remember that aluminum is very pliable. Any warping, denting or damage done will harm the integrity and seal of the seamless gutter and will eventually cause erosion and leaks. To cut your lengths of gutter using a workbench or sawhorse make sure that the length of the gutter is properly supported to avoid warps and dents due to bending. Cover the areas where the aluminum will rest during cutting with old towels or pieces of carpeting to avoid scratching the pre-sealed finish.

Step 3 - Cut With the Right Tools

The best way to cut aluminum gutters is with a fine-toothed hand saw or a miter saw. In either case, you must make sure to wear proper protective gear on your eyes, hair, skin, and hands. Use long smooth strokes and even pressure when cutting with the hand saw to avoid damage to the edges of the gutter. If you will be cutting using a miter saw make certain you wear heavy protective covering and full protective goggles and gloves as the miter saw will throw quite a bit of hot shrapnel during cutting. For this reason, you will also want to make sure that you cover the ground with some sort of protective mat to avoid fires.