How to fix a sagging gutter
Often yes, and it is usually hangers rather than the gutter. But a sag caused by rotten fascia is a different job entirely, and doing the easy version on rotten wood wastes the afternoon.
- Doing it yourself
- $25–$80
- Typical contractor price
- $200–$500
This job puts you on a ladder
- Set the base one foot out for every four feet of height. Steeper than that and it slides out from under you; shallower and it tips backwards.
- Extend the ladder at least three rungs above the gutter and tie it off, or have someone foot it. Never rest a ladder on the gutter itself — aluminium will fold.
- Keep your hips between the rails. Reaching sideways past the rails is what puts people on the ground; move the ladder instead, however tedious that gets.
- Stay off it in wind, rain, or on wet grass. A ladder on soft ground sinks unevenly as you climb.
- Standing on the top two rungs is how most ladder falls happen. If you cannot reach from the third rung down, the ladder is too short.
Tools
- •Extension ladder
- •Cordless drill
- •String line or a long level
- •Tape measure
- •Awl or a screwdriver for probing wood
Materials
- •Hidden hangers with screws (one every 24 inches; 16 inches in snow country)
- •Replacement fascia board if the wood has gone
Step by step
Probe the fascia before anything else
Push an awl into the fascia board behind the sag. If it sinks in easily, the wood is rotten and no hanger will hold — stop here, because everything below assumes sound wood.
Watch out: This is the step people skip. New hangers screwed into rot pull out within a year, usually taking a longer section with them.
Work out the correct slope
Gutters need roughly a quarter-inch of fall for every ten feet, toward the downspout. Run a string line from the high end to the outlet so you are aiming at a real target rather than eyeballing level.
Replace the spikes with hidden hangers
If the gutter is held by long spikes through the front lip, that is usually the whole problem — spikes work loose as the wood expands and contracts. Hidden hangers clip inside and screw into the fascia.
Watch out: Reusing the old spike holes gives the new screw nothing to bite. Offset by an inch or two.
Space them for your snow load
Every 24 inches is the general rule. Anywhere that holds ice — most of the country — go to 16, and add one either side of each joint.
Test with water
Flush the run with a hose. Any standing water deeper than about a quarter-inch means the pitch is still wrong. Standing water is where mosquitoes breed and where ice starts.
Stop and call someone if
- The fascia is soft — that is a carpentry and roofing job, not a gutter one.
- The sag is more than about half an inch over a ten-foot run; the gutter has probably deformed and will not pull straight.
- The run is on the second storey.
Or read more about gutter repair.
Common questions
- Can I just push it back up and add a screw?
- It will hold until the first heavy rain. A sag means the support spacing or the fascia has failed, and one screw does not change either.
- How many hangers do I actually need?
- One every 24 inches, or every 16 where snow and ice load the gutter, plus one on each side of every joint and corner. Most sagging gutters were underhung from the day they went up.
Last reviewed September 19, 2026. General guidance only — your house, your roof and your local building code are what actually govern the work.