STEP FLASHING: Pieces of metal or other material that are used to flash roof projections such as chimneys, walls, curbs, etc. The pieces are installed between each course of roofing and generally have a vertical flange equal in length to that of the horizontal flange.

RIDGE VENT: An exhaust venting device located at the ridge of a roof that works in conjunction with a starter or under eave soffit vent and is used to ventilate attics. Ridge vents and their cooperative starter or soffit vents should be installed at a 1:1 ratio in order to function properly.

WOVEN VALLEY: A valley construction whereby the valley has a woven look which is done by overlapping alternate courses of shingles from both sides of the valley.

CDX PLYWOOD: Grade of plywood approved by the American Plywood Association for exterior use; often used for roof decks

OSB: Oriented Strand Board. A decking made from wood chips and
lamination glues.

POLYVINYL CHLORIDE (PVC): A thermoplastic polymer that can be compounded into flexible and rigid forms through the use of plasticizers, stabilizers, fillers, and other modifiers; rigid forms are used in pipes; flexible forms are used in the manufacture of sheeting and roof membrane materials

UNDERLAYMENT: A material installed over the roof deck prior to the application of the primary roof covering. Usually consists of fifteen (15#) or thirty (30#) pound organic felt but can also be self-adhering such as an ice and water protection membrane.

DRIP-EDGE: An installed lip that keeps shingles up off of the deck at edges, and extends shingles out over eaves and gutters, and prevents water from backing up under shingles.
Roof to Wall flashing:  Continuous metal flashing consisting of several feet of metal. Used at horizontal walls, bent to resemble an “L”.

DEAD VALLEY: An area that is absolutely horizontal or zero slope.

FASCIA: Vertical roof trim located along the perimeter of a building, usually below the roof level, to cover the rafter tails at the eaves. AKA: the boards behind the gutter.

WATER SHIELD: A watertight barrier used to seal water out at the eaves and rakes, in valleys, and around chimneys and skylights.

CRICKET: A pitched saddle construction at the back of the chimney or other vertical surface to deflect water around the chimney.

PAN METAL: Flashing used on the upper side of a roof penetration such as a chimney or skylight; sometimes referred as back pan.

ROOF TO WALL METAL: A roof transition flashing for installation to a building at a juncture between a vertical wall and an edge of a sloped roof, to prevent water flowing along the flashing from seeping behind siding located on the vertical wall and shingles located on the sloped roof.