Compare roofing quotes on a three-decker, joint by joint

A three-decker has often been re-covered without a strip, and a flat roof can carry several generations of membrane and gravel. Removing two layers is close to double the labor and double the disposal of removing one, and on a flat roof the weight coming off is considerable. A quote priced for one layer on a building that has three is not a lower price.

Under a flat membrane the deck is board, often with rot at the low corner where water has pooled for years. No one sees it until the old roof is off. A price per sheet, and the number the estimate assumes, bounds the risk. Silence leaves it to be settled on the day.

On a pitched roof, felt and synthetic are different products at different prices; on a flat roof the base sheet and the cap sheet are the whole system. "Included" is not a specification for either. Ask what product, by name, and where.

A flat roof drains sideways through a scupper, and a pitched roof over a heated top floor grows ice at the eave every winter. Where the membrane runs, and how far past the wall line, is a different roll count and a different day of labor on every building, and the quote should state it rather than imply it.

Where a porch roof meets the wall three stories up, or a dormer meets the main slope, the step flashing can be replaced or it can be sealed over and left. Sealing is quicker and it is the usual reason a roof only a few years old is staining a top-floor ceiling.

Most of these houses carry a chimney that no longer serves anything, and it still needs counterflashing let into the mortar, a sound crown, and a decision about whether it should come down below the roofline instead. All of that is separate work, and it is regularly absent from the first number.

A flat roof has almost no attic to vent, and a pitched three-decker has one that belongs to whoever lives on the third floor. Reinstalling what was there changes nothing; adding intake and exhaust where there was none is real work. The quote should say which of the two it is doing.

On a pitched roof the metal edge and starter course take the ice each winter. On a flat roof the equivalent is the parapet cap and the edge metal, and both are just as easy to leave off a quote. Either way, it is the edge that lets go first.

Built-in gutters on the older houses are specialist work that some crews will not price. Hung gutters on a three-decker come down and go back up, get replaced, or get bent by a ladder. Scuppers on a flat roof are their own line entirely. The quote should name what happens to each.

Every city and town here runs its own building department, and a roof on a three-unit building may draw a different inspection than a single-family. Included in the price, billed separately, or left to the owner are three different deals.

The manufacturer stands behind the membrane or the shingle. Someone has to stand behind the seams, the flashings and the scuppers, which is where these roofs fail. A material warranty with no written labor warranty leaves the part that matters uncovered.

A dumpster on a street with resident parking, gravel and old membrane coming down past three floors of windows, a magnet sweep along a sidewalk the neighbors use. These are the lines that produce complaints after the crew is gone, and a quote that addresses them has walked the property.