Roofing in Maryland has to answer more than one climate, even though your house sits in only one of them. Western counties load ice along the eaves and punish a short flashing detail. Piedmont storms drop limbs into valleys and lift shingles on the windward face. The Shore throws salt wind and sideways rain at ridges, chimneys, and every metal edge. Say where the house is before you describe the leak.
Most calls start smaller than a whole roof. A ceiling stain, granules in the gutter, a drip at a chimney, or shingles cocked up after wind are the usual openers. Flat spots over porches and additions fail differently from a steep main roof. Flashing cut into brick is a usual weak point on older houses in the settled towns. Tell us whether the water shows up in a wind-driven rain, in a long soak, or on the first thaw after ice.
Air under the roof matters as much as the covering on top. A humid summer cooks the deck if air cannot move from the soffit toward the ridge, and a cold western night builds ice where heat leaks up. Dark streaks and moss show on shaded slopes under heavy trees, especially near the bay and in older neighborhoods with big canopies. Ventilation, shade, and the age of the covering belong in one conversation, not separate guesses.
From the ground, note soft fascia, exposed fasteners, patched spots, and any place a gutter has pulled away from the edge. If you can look into the attic without climbing, say whether the insulation is wet. Do not walk a steep, soft, or icy roof just to sound prepared. The call needs the symptom, the county, and whether a storm just moved through. If a claim is also on your mind, say that after you describe the leak.
A repair and a replacement are different jobs. Slate and metal still cover some older houses. Many others carry asphalt, sometimes in more than one layer. Ice in the mountains, humidity in the middle of the state, and salt wind near the bay each leave a different mark on the same list of parts. Say what you think you need, and stay open if the roof says otherwise. Call the number on this page.