Gutters are easy to overlook until they fail. When they overflow, sag, or dump water next to the foundation, the damage can show up as rotted fascia, a wet basement, or cracked concrete. A good gutter install is mostly about getting a few unglamorous details right.
Sizing for your roof, not just your house
Gutter size should match the amount of water the roof sheds, which depends on roof area, pitch, and local rainfall. Many homes do fine with 5-inch K-style gutters, but large or steep roofs, and homes in areas with heavy downpours, often need 6-inch gutters and larger downspouts. A contractor should be able to explain why they chose the size they did.
Pitch toward the outlets
Gutters should slope gently toward each downspout so water does not sit and collect debris. The slope is small, often about a quarter inch for every 10 feet, so it should not be obvious from the ground. On long runs, a good installer may pitch the gutter both ways from the middle toward two downspouts.
Hangers that hold
Hidden hangers should be spaced closely enough to carry the weight of water, ice, and wet leaves, and fastened into solid wood behind the fascia. If the fascia is soft or rotted, it should be repaired before new gutters go up. Hanging new gutters on bad wood is a common shortcut that shows up as sagging a year or two later.
Seamless runs and sealed corners
Seamless gutters are formed on site to the exact length of each run, which removes the joints where most leaks start. The corners (miters) and end caps still need careful sealing. Ask whether miters are made on site or pre-formed, and how they are sealed.
Downspouts that carry water away
This is where many installs fall short. Every downspout should discharge water well away from the foundation, using extensions, splash blocks, or underground drain lines that daylight downhill. A downspout that empties right next to the house undoes most of the gutter’s work.
Gutter guards, done right
Guards can cut down on cleaning, but they need to be installed without lifting or cracking the shingles and without voiding the roof warranty. Ask how the guard attaches and whether the roofing manufacturer allows it.
Questions to ask a gutter contractor
- What size gutters and downspouts do you recommend, and why?
- Will you check and repair the fascia first?
- What hangers do you use, and how far apart?
- Where will each downspout discharge?
- Are you licensed (where required) and insured?
These are the same points our gutter judges look at when scoring an entry for the Built Right Award.