Checking gutters and downspouts before heavy rain

Before a period of heavy rain, the most useful gutter check is simple: confirm that water can enter the gutter, travel along it and leave through the downspouts without spilling over the edge or soaking the walls. A gutter packed with leaves or shingle grit can overflow within minutes of a downpour, and the water it dumps lands right against the foundation and siding. A thorough check takes less than an hour on most single-story homes, and it comes down to clearing debris, testing the flow and making sure each downspout carries water well away from the house.

Clear the debris before anything else

Start by removing whatever has collected in the gutters. Leaves, pine needles, seed pods and roof grit are the usual culprits, and the grit that washes off asphalt shingles piles up over time. Use a plastic gutter scoop or a gloved hand rather than a metal tool that can bend the gutter or scratch its finish. Bag the debris as you go, and check the bottom of each downspout, where leaves often compact into a plug.

Ladder work needs care. Set the ladder on firm, level ground, have someone steady the base if possible, and keep your belt buckle between the side rails rather than leaning out to reach a far section. Do not work from a wet ladder or in wind or rain, and do not climb onto a steep or fragile roof to reach a gutter. A roof that is high, steep or in poor condition is a job for a professional gutter service.

A large amount of shingle grit in the gutters is worth noting. A steady loss of granules suggests the roof surface is wearing, so mention it to a roofer if it keeps happening.

Test the flow with water

Once the gutters are clear, run a garden hose at a moderate flow into the far end of each gutter run and watch what happens. Water should move steadily toward the downspout. Pooling in one spot points to a sagging section or a stretch that has lost its slope. Drips or streams at a joint point to a failed seam. Mark each problem spot with a piece of tape, let the gutter dry, and then seal the joint with a gutter sealant rated for the job.

Sagging gutters are common, and a frequent cause is loose or missing hangers. Brackets are typically spaced every two to three feet along a gutter run, and a section that sags between them can hold water and pull away from the fascia. Tighten or replace brackets that have pulled loose, and check that the gutter still pitches gently toward the downspouts. A flat stretch anywhere along a long run will hold water until the next storm arrives.

Check where each downspout discharges

A downspout that dumps water right at the base of the wall is one of the most common reasons a foundation stays wet. Water should leave the downspout and travel several feet away from the house, commonly four to six feet, through an extension, an underground drain or a splash block set on ground that slopes away from the wall. A short elbow at the bottom, with nothing beyond it, leaves the water in the same place as the wall.

Test the discharge with the hose. Run water into the top of the downspout and watch the outlet. Water should flow freely and land on ground that slopes away, not on a patio slab that slopes back toward the house, a walkway that channels it toward a door, or a window well. Make sure extensions are secured so that wind does not knock them out of place, and that the joints between downspout sections are tight enough to keep water inside.

Spot the signs of overflow

Overflow often shows up in the places below the gutter rather than in the gutter itself. Look for water running over the front edge in a sheet, especially at the lowest point of a run, which marks where the gutter is holding too much. Stains or streaks on fascia boards, siding or the wall below the gutter line suggest that water has been spilling for some time, and peeling paint at the bottom of a wall can have the same cause.

On the ground, look for soil washed out from under the gutter line, splash marks on the foundation, bare channels cut through mulch beds, and small puddles that linger after the rain has stopped. Soft or dark fascia boards at the roof edge can mean the gutter has been leaking into the wood for a long time. Each of these signs points to a gutter or downspout that is not moving water away quickly enough.

After a heavy rain, observe the gutters from a window, or wait until the rain has stopped before going outside. A storm is not the time to be on a ladder or walking near the house. Keep a short note of what you cleared, which joints you sealed and which problems remain, and repeat the check before each storm season. A gutter that is cleaned and tested regularly is far more reliable than one that is only looked at after the water has already reached the wall.