Gutter guards for Washington, DC homes

Not every house does. A rowhouse on a treeless block in Trinidad or Eckington may only see a handful of leaves blown in from the street, and a cleaning once a year handles that for far less money. We'll say so if that's your situation.

The math changes under big canopy. Upper Northwest streets around Chevy Chase DC and Tenleytown, older lots in Bethesda and Arlington, and wooded subdivisions in Fairfax and Burke sit under oaks, tulip poplars, maples and white pines. Those gutters can fill in a single October week, then pack again with helicopter seeds in May.

A clogged gutter does more harm than people expect. Overflow soaks the fascia and soffit, runs down the siding, and pools at the foundation. In winter, a gutter full of frozen leaves helps ice build at the eave, which can force meltwater back under the shingles.

Stainless steel micro-mesh over a rigid aluminum frame is what we install most. The mesh is fine enough to stop pine needles and the gritty shingle granules that wash off asphalt roofs, and the frame keeps it from sagging under a wet load of leaves. It handles the heavy downpours we get in July without much overshoot.

Solid surface or reverse-curve hoods rely on water sticking to a rounded nose and wrapping into the gutter. They shed leaves well, but in a hard storm on a steep roof some water sails right past. We fit them mainly where the roof pitch is low and the debris is mostly large leaves.

Snap-in plastic screens and foam inserts sold at big box stores are cheap, but they warp in summer sun, hold onto pine needles and turn into a second layer of clogging. We pull a lot of them off houses before fitting something that lasts.

• Stainless micro-mesh: best all-round choice, stops needles and grit
• Perforated aluminum: decent for big leaves, lets small debris through
• Reverse-curve hood: low-pitch roofs with mostly broad leaves
• Foam or plastic inserts: we don't recommend them

Good micro-mesh guards slide under the first course of shingles at the back edge and screw to the front lip of the gutter. We lift the shingle tab gently with a flat bar so the sealant strip isn't torn, and we never nail through the shingles to hold the guard down. Done carelessly, that back-edge detail can void a shingle warranty or start a leak.

On slate and tile roofs we use a guard that fastens to the gutter only, with no part going under the roofing. Lifting slate to tuck a guard under it cracks pieces, and those slates are often a century old. Standing seam metal gets a similar gutter-mounted guard set below the panel drip.

Before any guard goes on, the gutter has to be sound and pitched correctly. A guard on a sagging, leaking run just hides the problem. If the troughs need work first, we'll handle the gutter repairs during the same visit.

Rowhouses get a different treatment. The rear gutter on a Capitol Hill or Bloomingdale house often catches debris from a single street tree or an alley ailanthus, plus whatever blows across the flat roofs next door. A short run of mesh over that one gutter costs little and keeps the downspout boot below from packing with leaves.

Where the roof drains through a parapet opening into a conductor head, we fit a domed strainer or a mesh cap over the head instead of a gutter guard. Those strainers sit at the outlet where clogs actually happen, and we can reach them from the roof during routine checks. A blocked head on a flat roof backs water up against the parapet, which is a far bigger problem than an overflowing eave gutter.

No guard ends gutter upkeep for good. Pollen, maple flowers and fine dust can form a mat on top of micro-mesh, especially under oaks in spring. A soft brush on a pole, or a light rinse from the ground, usually clears it. Most homeowners with good guards go from four cleanings a year to a quick check once or twice.

Guards also don't fix undersized gutters. If water overflowed a clean 5-inch gutter before, it will still overflow with a guard on top. In that case, upsizing the gutter and downspouts comes first and the guard follows.

We include a guard check in our roof maintenance visits, so the mesh gets brushed off when we're already on the roof. Call (202) 771-7443 and tell us what trees hang over your house; it tells us most of what we need to know.