Gutter installation in Washington, DC

Most of the gutters we pull down around Washington are 5-inch K-style runs sized for gentler rain than the region now gets. A summer thunderstorm can deliver water faster than a narrow trough and a 2x3 downspout can carry it, so the front lip spills even with nothing in the gutter.

Pitch is the other common fault. Gutters hung dead level, or bowed between hangers that have pulled out of soft wood, hold standing water that breeds mosquitoes, rots the board behind them and adds weight every time it rains. We set a fall of about a quarter inch per ten feet toward each outlet and check it with a level before the last hanger goes in.

Downspout count matters as much as gutter width. A long run on a center-hall colonial with one downspout at the far corner forces all the water to travel the full length, and it backs up halfway. Adding a second outlet near the middle often does more good than going to a bigger trough.

On a Petworth rowhouse, the front of the roof usually drains back to a rear gutter or through an opening in the back parapet. That rear gutter hangs over a narrow yard, and its downspout often ties into a cast iron or clay line running under the patio toward the alley or the sewer. When we replace the gutter, we test that tie-in first, because a new gutter feeding a clogged boot just moves the overflow to the ground.

If the underground line is broken or packed with roots, we tell you plainly and show you where it stops taking water. Sometimes the fix is a new boot and a cleanout. Sometimes it means running the downspout to a splash block or a short extension until a plumber clears the line.

Where the rear roof drains through a parapet, the gutter starts at a conductor head under the opening rather than along an eave. Those heads rust through and fill with leaves, so we size the replacement to hold a heavy burst without spilling down the brick. Problems at the opening itself are handled under scupper and roof drain repair.

Seamless gutters in .032 aluminum, K-style profile, cover most houses we work on. We roll them from coil on a machine on our trailer, cut each run to the exact length of the eave and join only at the inside and outside corners. That removes the mid-run joints where older sectional gutters drip.

Six-inch troughs with 3x4 downspouts make sense on steep slate roofs, big hip roofs in Bethesda and McLean, and anywhere a lot of roof funnels into one valley. On a small porch roof a 5-inch run is still fine. We pick the size from the square footage and pitch draining to each run, not from a single default.

Copper half-round gutters belong on many Georgetown and Cleveland Park houses where the original detail was copper and historic review expects it. They cost more and take more labor at the joints, which we solder rather than caulk. Galvanized steel is still available for buildings that need it, but it rusts much sooner than aluminum unless it's kept painted.

• Aluminum K-style, 5 or 6 inch: most homes, wide color range
• Copper half-round: historic facades and slate roofs
• Galvanized steel: rough-use commercial eaves, needs paint
• Oversized 3x4 downspouts: steep roofs and big valleys

Hangers are where most installs fail. We use hidden screw-in hangers every 24 inches, closer at valleys and under slate where snow slides, driving the screws through the fascia into the rafter tails wherever we can find them. Spikes and ferrules, the old method, work loose as the wood shrinks and swells through the seasons.

Before a new run goes up we push a screwdriver into the board behind it. If it sinks in, we take care of replacing the rotted fascia first, because a new gutter screwed into rot will be on the ground after the first ice load. That work is priced separately so you can see exactly what it adds.

We also slide drip edge or a gutter apron under the first course of shingles so water can't run behind the trough. On houses where the shingles stop short of the gutter, that small strip of bent metal is the difference between a dry fascia and a stained soffit. Call (202) 771-7443 and we'll measure the eaves and walk the fascia with you before quoting.

Guards make the most sense on houses under oaks, tulip poplars and pines, which describes much of upper Northwest, Takoma Park and the older Fairfax subdivisions. If your gutters fill twice a year, a good screen pays for itself in avoided ladder work. If they barely see a leaf, skip it and keep the money.

Adding guards during installation costs less than coming back later, because the setup is already done and the trough is open. Our page on gutter guards explains which screens hold up under pine needles and which ones overshoot in heavy rain.