Asphalt shingle roofing in Washington, DC

Shingles belong on roofs with real pitch, roughly 4 in 12 or steeper. That covers the detached colonials of Chevy Chase DC and Tenleytown, the Cape Cods across Brookland and Woodridge, and most of the split-levels and ramblers in Silver Spring, Annandale and Springfield. They do not belong on a flat rowhouse roof, no matter how cheap the bundle looks.

Plenty of DC homes mix the two. A Wardman-era porch-front rowhouse may carry a low-slope main roof behind the parapet and a short shingled front slope over the porch. We treat those as two jobs that share one tie-in, with a membrane on the flat section and shingles only where the pitch can shed water.

Shingles also work where historic rules allow them. Inside a historic district, swapping slate for asphalt on a visible slope usually needs Historic Preservation Office approval, and on many Victorian facades the answer is no. In those cases we point owners toward synthetic slate or a slate repair plan instead.

Most early shingle failures we see trace back to the layers beneath. We strip the old roof to bare sheathing, swap any delaminated plywood or soft planks, and nail the deck down again where it has lifted. Older homes in Takoma and Cleveland Park often have 1x6 board decks with gaps, which need careful nailing or an overlay of new sheathing.

Next comes self-adhered ice and water membrane along the eaves, in every valley and around chimneys and skylights. Washington does not get deep snow most winters, but a few freeze and thaw cycles a year are enough to back meltwater under the bottom courses. Synthetic underlayment covers the rest of the deck, lapped and fastened to the manufacturer's spacing.

Metal finishes the system. New drip edge goes on every eave and rake, valleys get open metal or a tight closed-cut detail, and every chimney gets new step flashing woven into the courses with counter flashing set into a fresh mortar joint. Reusing rusty old step flashing is a common shortcut, and we don't take it.

Architectural laminated shingles are what we install on nearly every job. They carry better wind ratings than old three-tab strips and hide minor deck waviness on older houses. We install lines such as GAF Timberline HDZ, CertainTeed Landmark and Owens Corning Duration, picking color and profile to suit the house rather than the latest catalog trend.

Heavy shade under mature oaks and tulip poplars, common in upper Northwest and Takoma Park MD, invites algae streaks and moss on north slopes. Shingles with copper-bearing algae resistant granules slow the black streaking. Lighter colors also run cooler under July sun, which helps a bit with attic temperature.

Ventilation decides how long any shingle lasts. Many 1940s Capes have little or no soffit intake, so attics bake all summer and sweat all winter. We cut continuous ridge vent and add intake at the eaves when the framing allows, and our attic ventilation work covers houses with knee walls or finished half-stories.

• Architectural laminated shingles for most homes
• Algae resistant granules for shaded lots
• Impact rated shingles where hail has been a problem
• Designer profiles that mimic slate or shake on period homes

Most shingle damage around Washington comes from short, violent summer storms and the occasional derecho rather than long winter blizzards. Gusts lift the leading edge of a course, break the sealant strip and fold the tab back. Once a tab has creased, it rarely reseals, and the next storm usually takes it.

We nail to the manufacturer's high wind pattern on every roof, with six nails per shingle where the spec allows, and we keep fasteners inside the narrow nailing zone. Starter strips with factory adhesive go along every eave and rake, which is where wind uplift begins. Those small steps cost little during installation and save a lot of tarping later.

Hail is less common here, but it does hit parts of Montgomery and Fairfax counties every few years. If your roof took a beating, our storm damage team can document the bruising before you decide between repair and a claim-funded replacement.

Shingle tear-offs throw a lot of debris. We set tarps over foundation beds, lean plywood against windows near the drop zone, and park the dumpster or trailer where it won't crack a driveway. On tight DC lots the dumpster often goes in the alley or the street, and the public space permit for that is part of our job.

Nails are the real hazard. We run rolling magnets across the lawn, driveway and alley at the end of each day and again at final cleanup. Gutters get flushed of loose granules and the odd shingle scrap so the first rain doesn't overflow onto the porch.

When the roof is done, we hand you photos of the deck repairs, the underlayment at the eaves and the chimney flashing before the shingles covered them. That record is useful for your insurer and for any buyer's inspector down the road.