Shingles in the attic and nails through the porch ceiling: what a re-roof should leave behind

In the Chicago case, the owner says the crew drove the old nails down through the deck instead of pulling them, and that neighbors' window screens were torn and their plants destroyed.

Some mess indoors comes with a tear-off. Bill Ragan, who runs a roofing company in Nashville, writes that the attic gets a coating of debris, sawdust and splinters, so owners should ask before work starts for the attic to be covered; the crew then rolls up the plastic and carries it out. Whole shingle pieces and trash left on a furnace are a cleanup failure. Shingle maker IKO's installer guide ends with clearing the roof, valleys and gutters of debris and running a magnetic sweeper over the driveway and yard.

Nails are less simple. IKO tells installers to remove old nails or hammer them flush with the deck before new roofing goes on, so setting them is allowed. The Asphalt Roofing Manufacturers Association says new nails must reach at least 3/4 inch into the deck, or come 1/8 inch through thinner sheathing, so where the underside of the deck is in view, points will show. ARMA tells owners who object to check the shingle maker's instructions and the building code for approved alternatives, which works only before the job starts.

What to put in the contract: tarps over flower beds and protection for the neighbors' property, an attic cover, magnet sweeps, how old nails will be handled, the nail plan over any exposed ceiling, and a walk-through with the owner before the final payment.