Use this glossary as a quick reference as you navigate your roofing job.

A

• Asphalt Shingles: Common roofing material made from asphalt for waterproofing.
• Apron Flashing: A term for metal flashing used at chimney fronts.

B

• Barge Board: A board fastened to the projecting gables of a roof.
• Bitumen: A black, sticky substance used in certain roofing materials.

C

• Cricket: A peaked water diverter installed behind chimneys or along roof ridges.
• Counterflashing: Metal flashing that's installed to prevent moisture entry.

D

• Decking: The substrate over which roofing is applied, usually plywood or OSB.
• Dormer: A protruding mini-roofed structure with a window.

E

• Eaves: The lower border of the roof that overhangs the walls.
• EPDM (Ethylene Propylene Diene Monomer): A durable synthetic rubber roofing membrane.

F

• Flashing: Materials used to waterproof a roof around any projections.
• Fascia: A board that runs along the roof's edge, connecting the roof and the outer walls.

G

• Gable: The triangular portion of a wall between the edges of intersecting roof pitches.
• Granules: Mineral particles coated on the surface of shingles.

H

• Hip Roof: A roof with sloping ends and sides.
• HVAC Penetrations: Vents or exhausts for heating, ventilation, and air conditioning systems.

I

• Ice Dam: A ridge of ice that forms at the edge of a roof and prevents melting snow from draining.
• Insulation: Material used to keep heat in or out of a home.

J

• Joist: Horizontal structures that support the decking.
• J-Channel: A type of trim used around windows and doors on the roof.

K

• Kick-Out Flashing: Flashing that diverts water away from the cladding.

L

• Laminated Shingles: Shingles containing more than one layer of material for durability.
• Louvers: Slatted devices installed in a gable or soffit for ventilation.

M

• Membrane: A type of roofing system for flat roofs, made from modified bitumen.
• Mansard Roof: A four-sided gambrel-style hip roof.

N

• Nesting: Installing a new layer of shingles over an old layer.
• NRCA (National Roofing Contractors Association): An association that represents all aspects of the roofing industry.

O

• Overhang: The portion of the roof structure that extends beyond the exterior walls.
• OSB (Oriented Strand Board): A type of decking material made from compressed wood strands.

P

• Pitch: The angle or slope of a roof.
• Ply: A layer of roofing (in felt, ply sheet, etc.).

Q

• Quarter Sawn: A type of wood cut that's less likely to warp.

R

• Rafter: The supporting framing to which the roof deck is attached.
• Ridge: The top edge of two intersecting sloping roof surfaces.

S

• Soffit: The exposed surface beneath the overhanging section of a roof eave.
• Shingle: A piece of roofing material that is laid in overlapping rows.

T

• Tar: A black, viscous material used in roofing.
• Truss: A framework, typically consisting of rafters, posts, and struts, supporting a roof.

U

• Underlayment: A layer of material placed beneath shingles to provide additional protection.

V

• Valley: The internal angle formed by the intersection of two sloping roof planes.
• Vapor Barrier: Material used to prevent moisture from penetrating the roof.

W

• Warranty: A promise by the manufacturer or roofer regarding the quality and performance of roofing materials or work.
• Weep Holes: Small openings that allow for water drainage.

X

• Xactimate: A software used for estimating construction and repair costs, commonly in roofing.

Y

• Yield Point: The point at which a material begins to deform permanently.