I installed gutters on my garage last summer. Not complicated, but there are a few things that’ll bite you if you don’t know about them going in.
The Materials
Standard seamless aluminum gutters are what most pros install, but those require a machine. For DIY, you’re looking at sectional gutters – they come in 10-foot lengths that you connect with slip joints.
K-style gutters are most common now. The old half-round style looks better on historic homes but costs more and is harder to find.
Buy everything at once: gutters, end caps, inside/outside corners, downspout outlets, downspouts, elbows, hangers, and brackets. Going back to the hardware store three times is annoying.
The Slope
This is where people mess up. Gutters need to slope toward the downspout – quarter inch per 10 feet of run. Sounds minor, but get it wrong and water pools in the middle.
Snap a chalk line from your high point to your low point. Mark both ends carefully before you start hanging anything. Check it twice.
Hanging the Gutters
Hidden hangers are easier than the old spike-and-ferrule method. Space them every 2 feet – closer if you get heavy snow.
Drill the hangers into the fascia board, not just into the sheathing. You want something solid holding them up when they’re full of water and ice.
Connecting Sections
Slip joints connect the gutter sections. They overlap a few inches, and you seal them with gutter sealant. Don’t skimp on the sealant – leaky joints are the most common problem I see on DIY gutter jobs.
Same with end caps. Press them on, then seal around the inside edge. Let the sealant cure before you test anything.
Downspouts
Cut a hole in the gutter for the downspout outlet. Most have a template. The downspout attaches with a couple of elbows, then runs down the wall and away from the foundation.
Aim to discharge at least 4 feet from the house. Farther is better. Water pooling at your foundation is the whole problem you’re trying to prevent.
