Roofing in the District of Columbia means two different roofs more often than people admit. Many rowhouses carry a low-slope roof behind a parapet, drained by scuppers that clog with leaves and alley grit. Other houses, especially on the wooded edges, have pitched roofs under large trees. Both sit in humid summers and the occasional ice. Say which roof you have before you describe the ceiling stain.
On a flat roof the failure is often a pond, a split seam, or flashing where the rear ell meets the main house. On a pitched roof it is lifted shingles, a valley full of oak leaves, or flashing pulled away from a chimney. Party-wall flashing on a row can send water sideways into a room that looks unrelated. Tell us whether the drip comes in a wind-driven rain, after water has sat, or only when ice melts. The timing is the diagnosis you can give without climbing.
Access is part of the work. A narrow row, a roof hatch, and an alley full of wires are not a suburban driveway. A detached house on a slope has its own problem: limbs, a steep walk, and a deck you should not wander onto. Do not climb a parapet. From inside, note which floor stains and whether a neighbor on the shared wall has the same mark. Several old layers, or a coating smeared over a tired membrane, are facts worth stating if you know them.
Humidity keeps shaded rear roofs from drying, and a blocked scupper will rot a deck that still looks fine from the street. Ice is less constant here than in the high country, but a cold spell still backs water under a weak edge. If a claim is on your mind, describe the leak first. The District gives roofs little mercy in a summer downpour because the water has a short path and a small drain.
Say repair or replacement, and say flat, pitched, or a mix with an ell. Roofing in the District of Columbia is parapets, scuppers, party walls, and, on the green edges, tree-covered slopes. Call the number on this page.