Roof maintenance in Washington, DC

On a flat rowhouse roof, we start at the rear: scupper, conductor head and the gutter or leader below. Then we walk the field of the roof looking for blisters, open seams, ponding and spots where the coating has worn through to the base membrane. Parapet flashing, coping joints, plumbing vents, the hatch and any skylights get checked one by one.

On a pitched shingle or slate roof, we look at valleys, chimney flashing, pipe boots, ridge vent and any slipped or cracked pieces. Rubber pipe boots dry out and split in our summer sun after ten to twelve years, and they're one of the most common slow leaks we find. Replacing one during a maintenance visit takes minutes.

Small repairs are part of the visit: resealing a counterflashing joint, replacing a cracked vent boot, refastening a lifted piece of edge metal, swapping a broken slate. Anything bigger we photograph, price and leave for you to decide.

• Gutters, scuppers, drains and downspouts cleared
• Flashing at chimneys, walls, skylights and vents checked and resealed
• Seams, blisters and coating wear on flat roofs inspected
• Slipped shingles or slates and lifted edge metal fixed
• Dated photos and a short written condition note

Fall visits come after the leaves drop, usually mid-November in DC and a bit earlier in the Maryland and Virginia suburbs. Clearing the outlets then sets the roof up for winter, when a clogged drain can freeze and a blocked gutter helps ice form at the eave. It's also the last good weather for sealants and coatings to cure.

Spring visits, after the oak catkins and maple seeds fall, catch whatever winter did: freeze-thaw cracks in sealant, slates popped by ice, flashing loosened by wind and gutters bent by snow sliding off a steep roof. That visit also prepares the roof for the summer thunderstorm season, when outlets have to move a lot of water quickly.

Houses under heavy canopy in upper Northwest, Takoma Park or the older parts of Arlington County may need a third visit in early summer. We'll tell you after the first year whether yours is one of them.

Storms change the calendar. After a derecho, a tropical remnant or a night of high wind, a quick look at the roof is worth more than waiting for the next scheduled visit. Maintenance customers get priority for those post-storm checks, since we already know the roof and have its last photos on file to compare.

A flat roof's life depends heavily on upkeep. A modified bitumen or EPDM roof that gets its drains cleared and seams checked twice a year will typically outlast an identical neglected roof by years. Ponding water, UV exposure and clogged outlets are what age a membrane fastest, and all three are things maintenance addresses.

Silver or white coatings on DC rowhouse roofs wear thin at walkways, around the hatch and near the rear outlet first. Touching those spots up during a maintenance visit costs little compared with a full recoat, and it keeps the sun off the membrane underneath. When the coating has worn across most of the roof, we'll suggest a full recoat and price it.

We also look at what's been added to the roof since the last visit: a new satellite mount screwed through the membrane, an HVAC condenser on unprotected sleepers or a new deck. Those additions cause a surprising share of leaks we trace.

Many houses in Cleveland Park, Chevy Chase and Takoma have slate roofs installed nearly a century ago. Good slate can keep going, but individual slates crack and the nails holding them rust off. Replacing a few slates each year with copper nails and slate hooks keeps the roof tight; ignoring them for a decade turns into a much larger slate repair job.

Standing seam and flat-lock metal roofs on porches and bay windows need their paint watched. Once bare steel shows, rust spreads quickly. We spot-prime and paint small areas during maintenance, which can delay a full repaint or replacement for years.

On both, we walk carefully. Slate breaks under careless feet, so we use hook ladders and roof jacks rather than walking the field, and soft-soled shoes on metal.

Every visit ends with dated photos and a brief note on what we found and fixed. Over a few years, that becomes a history of the roof. It helps when a buyer's inspector asks about the roof, when an insurer wants proof the roof was maintained or when you're deciding whether replacement can wait another year.

If you're planning to sell, those records also make a roof certification simpler, because we already know the roof's condition and history. Call (202) 771-7443 to put your roof on our spring and fall schedule.