Clogged gutters before winter: what to clear yourself, when to call a pro
A step-by-step look at clearing fall leaves from gutters and downspouts, and the underground clogs and drainage calls that need a licensed pro.
Fall strips the trees fast, and whatever doesn't end up on the lawn tends to end up in the gutters. Before winter weather arrives, those channels need to stay clear enough to do their real job: moving rain off the roof and away from the house. According to DOE's stormwater guidance, just a few inches of rain on a roof can produce several thousand gallons of runoff, and gutters and downspouts are supposed to carry that water at least 5 feet from the foundation. Clogged gutters also set up one of the more damaging cold-weather problems: once snow piles up on a roof that can't drain, the water can refreeze into ice dams, and enough accumulated ice and water can strain the roof structure. This guide covers what a homeowner can check and clear safely, and where the job turns into one for a licensed pro.
What's going on
Gutters exist to catch runoff and send it somewhere that won't erode the yard or soak the foundation. BASC's gutters and downspouts guide notes downspouts can also drain into an underground catchment system, as long as it sits at least 10 feet from the foundation. For water to actually reach the downspouts, the gutter run needs a slight slope, at least 1/16 inch per foot, and downspouts are typically spaced every 20 to 50 feet along the run. Leaves, pine needles and shingle grit undo that math fast: once debris fills the channel, water backs up over the edge instead of reaching the downspout, which is exactly the setup that leads to ice dams, since BASC says ice dams can start forming with as little as 2 inches of snow sitting on a roof that's already struggling to drain.
What you can safely check or fix
Clearing visible leaves, needles and grit out of the gutter channel and the downspout openings is a job most homeowners can do safely from a secure footing. Once the channel is clear, what's worth checking next follows directly from how BASC says a gutter system is supposed to work.
- Clear leaves, needles and grit from the gutter channel and out of each downspout opening so you can see the channel itself.
- Check the channel's pitch. A gutter needs at least 1/16 inch of slope per foot to carry water toward the downspouts, so a cleared section still holding water on a dry day usually has a sag worth addressing, not just leftover debris.
- Confirm each downspout empties at least 5 feet from the foundation, or into an underground catchment system set back at least 10 feet.
- Walk the roofline and check that downspouts fall roughly every 20 to 50 feet; a long unbroken run is often where water overflows first.
- Note the gutter material while you're clearing it. Copper and galvanized steel resist dents and cracks from branches and ladder contact better than vinyl or aluminum, so handle those sections carefully.
- Trace where the downspout empties and make sure it was never tied into the home's perforated foundation drain pipe, since that connection soaks the foundation instead of protecting it.
Where to stop and call a pro
A few situations call for more than a cleared channel and a cleared downspout.
Stop here: if a downspout feeds into a buried drain line or underground catchment system and the clog sits below grade, that's a job to have evaluated first. Figuring out how that water interacts with the soil around the foundation is work for a certified hydrologist, soil scientist or engineer, not a gutter cleaning.
A gutter's drain pipe should also never be tied into the home's perforated foundation drain pipe, since BASC says that connection soaks the foundation instead of protecting it. And once snow has piled up enough to start forming ice dams, something BASC says can begin with as little as 2 inches of accumulation, enough ice and water buildup on the roof can strain the structure itself, a roof and attic problem beyond what gutter clearing can fix.
What to tell the pro
A few details save time whether the call is about a buried clog or a drainage question. Mention the gutter material: BASC notes copper and galvanized steel hold up to ladder and branch impacts better than vinyl or aluminum, which can crack or dent, so a pro may approach a repair differently depending on which you have. Give the channel size if you know it (residential runs usually come in 4, 5 or 6 inches) and roughly how far apart the downspouts are spaced, since the typical range is 20 to 50 feet along a run. If the issue is standing water or soil movement near the foundation rather than a surface clog, say so plainly, since that calls for whoever can assess the soil itself, a certified hydrologist, soil scientist or engineer, not a gutter cleaning.
Quick answers
How far from the house should a downspout drain?
At least 5 feet from the foundation, or into an underground catchment system set back at least 10 feet, according to DOE.
Why does a gutter still hold water after I clean it?
Usually a lost slope: gutters need at least 1/16 inch of pitch per foot to carry water toward the downspouts, so standing water in a cleared, dry-day gutter often means a sag, not leftover debris.
What if a downspout clog is underground?
Stop and call a pro. Figuring out how that water interacts with the soil around the foundation, including a buried line or catchment system, is a job for a certified hydrologist, soil scientist or engineer.