Roof inspection in Washington, DC

On a low-slope rowhouse roof, we walk the full surface and probe every seam we can reach. We look for blisters, splits, alligatored coating, ponding marks and soft decking. At the parapets we check whether base flashing is fully stuck to the brick, how it is terminated and whether the coping above has open joints.

On pitched roofs, we look at shingle granule loss, curling, cracking and nail pops, and on slate we count broken, slipped and delaminating pieces. We check valleys, ridge caps, and step flashing at walls and chimneys, and we note the metal used for flashing, since that tells us how long the details will last compared with the roofing.

Every roof gets its penetrations checked: plumbing vents, exhaust fans, skylights, hatches, HVAC stands and chimneys. Then the edges and drainage: gutters, downspouts, scuppers, drains and any built-in box gutter at the cornice. Drainage problems cause more early failures than anything else we find.

Half the story is under the roof. In houses with an attic, we look at the underside of the decking for staining, mold, delamination and daylight around penetrations. We check insulation depth and whether soffit and ridge vents are clear, because a hot, damp attic ages shingles faster. Our page on roof and attic ventilation explains why that matters.

In rowhouses with no attic, we look at the top-floor ceilings and the upper walls for old stains, patched plaster and paint changes that hint at past leaks. A ceiling that has been repainted in one spot often tells us exactly where to look on the roof.

We also ask about history: when the roof was installed if you know, any past leaks, and whether work has been done since. That helps us judge whether an old stain is from a problem that was fixed or one that is still active.

A general home inspector often looks at a rowhouse roof from a ladder at the rear or not at all, and the report says the roof should be checked by a roofer. We go onto the roof, open the hatch, check the layers and give a realistic estimate of remaining life and near-term repair costs.

For buyers, that turns a vague line in the home inspection report into a number you can negotiate with. For sellers, an inspection before listing lets you fix small issues on your own schedule rather than under contract deadlines. If a lender or buyer needs a formal letter, our page on roof certification letters explains that option.

We work on tight timelines during the contract period. Call with the address, the inspection deadline and how the roof is accessed, and we set a time that fits the contract dates.

Flat roofs over about twelve years old, slate roofs with iron nails and roofs under large trees benefit from a yearly check. Fall is the best time, after the summer heat has shown its effects and before leaves, nor'easters and freeze-thaw cycles arrive. A spring check after winter is a good second visit for roofs that had problems before.

Homes under heavy canopy in neighborhoods like Brookland or Takoma see clogged drains and gutters every season. Pairing an inspection with clearing those outlets often heads off the most common winter leak. For ongoing visits, our roof maintenance plan covers the cleaning and small repairs together.

Solar arrays and roof decks sit on a roof for twenty years or more, and removing them later to reroof is expensive. Before either goes on, we check how many years the membrane or shingles have left, whether the decking is solid, and where the attachments will pierce the roof.

If the roof has less life left than the panels or the deck, it usually makes sense to replace it first. If it is in good shape, we mark the weak spots so the installer avoids them and note the flashing details we would expect at each mount. Our article on the roofing side of a rowhouse deck goes into the details.

You receive a written report with labeled photos of each part of the roof, a summary of condition and our estimate of remaining life in a range of years. Problems are sorted into urgent items, repairs to plan for in the next year or two, and items to watch.

Each repair item comes with a rough price range, so you can budget or negotiate. We do not pad the list. If the roof is in good shape, the report says so and suggests when to look again.

If a repair is urgent, such as an open seam above a bedroom or a slipped slate over the sidewalk, we tell you on the spot and can usually fix it the same visit if you want.