Gutter installation can be done by homeowners who have some DIY skills, but hiring a professional may be a smarter choice for people with steep roofs or complex roof lines. Hiring a pro will ensure the job is done correctly and can also prevent issues like misaligned gutters, damaged fascia and other problems that are difficult or impossible for laypeople to spot.

Determine the Number of Gutters You Need

Use a tape measure to accurately measure the length of each roofline where you will install gutters. Include a few feet for overlap, and purchase enough gutters to cover the entire area you will be working on. If you plan to use downspouts, be sure to factor in the number and placement of those as well. Gutters should slope toward downspouts to ensure proper drainage. A typical slope is 1/4 inch for every 10 feet of gutter.

Mark the Gutter Slope

Locate the high point of a gutter run and mark it on the fascia board with a chalk line. Then locate the low point of that same gutter run and mark it with a chalk line as well. Ideally, you should have an even slope from end to end.

Screw gutter hangers to the fascia boards at each location where you marked the high and low points of the gutter run. Use a ladder to reach these spots and fasten the hangers with 1/4-inch stainless steel lag screws that are long enough to penetrate the rafters 2 inches (use a drill to make the holes). If necessary, rub soap on the screws before using them so they’ll be easier to drive through the wood and into rafter tails.