Most roofs done in one day.

What usually goes wrong up there

Most of what sends people looking for a roofer is one of these six. None of them can be diagnosed from the ground — but knowing what you’re looking at makes it much harder for anyone to sell you the wrong fix.

• A stain on the ceiling near a chimney, wall or vent Don’t wait on this one

  Almost always the flashing, not the shingles. Flashing is the metal that carries water away where the roof meets something else, and it’s the single most common source of a leak — which is also why reusing old flashing on a new roof is the shortcut that costs people the most.

• Granules collecting in the gutters

  The mineral surface is what protects the asphalt underneath from UV. Once it sheds in quantity, the mat behind it starts aging fast. A handful after a new install is normal; a steady accumulation on a roof past fifteen years is the roof telling you its remaining life.

• Shingles curling, cupping or lifting at the edges

  Usually heat from below rather than weather from above. Without enough intake and exhaust ventilation, the attic cooks the underside of the roof and the shingles dry out early. It also voids most manufacturer warranties, which is why we size ventilation to the attic rather than guessing.

• Ice building up along the eave every winter Don’t wait on this one

  An ice dam, and it starts inside the house. Heat escaping into the attic melts snow higher up the roof; that water runs down to the cold overhang and refreezes into a ridge, and everything behind it backs up under the shingles. Gutters get blamed for this constantly and they’re rarely the cause.

• Daylight in the attic, or insulation that feels damp Don’t wait on this one

  Either something has penetrated the deck, or you’re looking at condensation from trapped moist air. Both rot decking from the top side down, and both are far cheaper to deal with before the sheathing goes soft.

• The roof is simply past twenty years

  Age alone isn’t a reason to replace anything. But it is a reason to have someone actually get up there with a camera, because at that point the difference between five more good years and a winter of water damage is not something you can see from the driveway.