Drip Edge At the eaves and edges of every roof, a piece of metal drip edge guides water away from fascia boards and prevents it from creeping beneath underlayment.
Valley Flashing The point where roofs intersect should be protected with flashing that extends horizontally several inches up each slope, away from the point of intersection.
Step Flashing Where a sloped roof intersects with a vertical plane, such as the side of a house or a chimney wall, small pieces of step flashing provide the necessary water-proof transition.

Roll Roofing Most often used on low-slope roofs and on outbuildings, mineral-surfaced roll roofing is inexpensive and easy to install. The material comes in 3-foot-wide rolls and is made of an asphalt-impregnated mat densely covered with mineral particles in black, grey or white. To avoid rippling or cracking, the product should be installed only during warm weather. Look for a metal drip edge, as well as asphalt cement at the roof perimeter and at every overlap.

Finish roofing is generally installed as soon as possible after the roof sheathing has been applied. The idea is to protect the sheathing and what’s beneath it from possible rain damage. It is, however, a good idea to make sure any projections through the roof deck, such as plumbing and exhaust vents, are in place before the roofing is installed. Siding can wait in place before the roofing is installed. Siding can wait slightly longer; it’s usually applied just after the doors and windows are set.

• Reject unsolicited offers to inspect or repair your roof.
• If your roof is leaking or you suspect other problems, ask at least three roofers to inspect it, diagnose problems and propose solutions.