Roofing Terms You Should Know

Deck/sheathing: The surface, usually plywood or oriented strand board (OSB), to which roofing materials are applied.

Dormer: A small structure projecting from a sloped roof, usually with a window.

Drip edge: An L-shaped strip (usually metal) installed along roof edges to allow water run off to drip clear of the deck, eaves and siding.

Eave: The horizontal lower edge of a sloped roof.

Fascia: A flat board, band or face located at a cornice’s outer edge.

Felt/underlayment: A sheet of asphalt-saturated material (often called tar paper) used as a secondary layer of protection for the roof deck.

Fire rating: System for classifying the fire resistances of various materials. Roofing materials are rated Class A, B or C, with Class A materials having the highest resistance to fire originating outside the structure.

Flashing: Pieces of metal used to prevent the seepage of water around any intersection or projection in a roof system, such as vent pipes, chimneys, valleys and joints at vertical walls.

Louvers: Slatted devices installed in a gable or soffit (the underside of eaves) to ventilate the space below a roof deck and equalize air temperature and moisture.

Oriented strand board (OSB): Roof deck panels (4 by 8 feet) made of narrow bits of wood, installed lengthwise and crosswise in layers, and held together with a resin glue. OSB often is used as a substitute for plywood sheets.

Penetrations: Vents, pipes, stacks, chimneys-anything that penetrates a roof deck.

Rafters: The supporting framing to which a roof deck is attached.

Rake: The inclined edge of a roof over a wall.

Ridge: The top edge of two intersecting sloping roof surfaces.

Sheathing: The boards or sheet materials that are fastened to rafters to cover a house or building.

Slope: Measured by rise in inches for each 12 inches of horizontal run: A roof with a 4-in-12 slope rises 4 inches for every foot of horizontal distance.

Square: The common measurement for roof area. One square is 100 square feet (10 by 10 feet).

Truss: Engineered components that supplement rafters in many newer homes and buildings. Trusses are designed for specific applications and cannot be cut or altered.

Valley: The angle formed at the intersection of two sloping roof surfaces.

Vapor retarder: A material designed to restrict the passage of water vapor through a roof system or wall.

Siding Terms You Should Know

Backerboard: Used to attach the siding, backerboard is usually thin sheets of flat material attached to the side of a house between the studs and siding.

Caulking: A sealant used on joints at intersections of different materials such as different types of siding to join the siding to pre-existing materials.

Clapboard: Wood plank siding made from either rectangular planks or taped planks that is installed horizontally and in an overlapping manner.

Course: A row of panels running the length of the house from one side to the other or, for example, vertical siding, from top to bottom.

Cupping: The warping of wood siding.

Drip Cap: Meets at the tops of doors and windows to help channel water away from those places.

F-Channel: Helps to keep soffit panels intact and secure in their place along the eaves of the roof.

Flange: A flat edge that attaches to a window to strengthen its position.

Flashing: A water resistant substance that is applied as a thin layer to help keep water and moisture out of crevices in your siding.

J-Channel: A product that is installed around windows that almost looks like trim, however, it is a barrier that keeps moisture and water out; not to be confused with a drip cap.

Lap: The overlapping of trim to allow room for siding to move as it settles.

Miter: Two pieces of molding that are cut on 45 degree angles, leaning on each other to form a right angle.

Nailing Hem: The edge of a piece of siding panel where the fastening holes are located.

Scoring: Etching a straight line into a piece of panel so it can be broken into two pieces with clean edges.

Square: A measurement that equals 100 square feet of siding.

T-Channel: Basically known as siding trim, a T-channel seamlessly connects two pieces of siding where the ends of two panels meet.

Underlayment: A product that is almost paper-thin and is spread on the exterior of your home preparing for the installation of new siding, works as a protectant for weather before the siding installation process can be completed.

Weep Holes: Very small holes that are made toward the bottom in order for condensation and moisture to run off and exit without harming your siding.