Glossary of Roofing Terms

A

Asphalt – A waterproofing agent applied to roofing materials during the manufacturing process.

B

Bitumen – A sticky, black, and highly viscous liquid or semi-solid form of petroleum used in roofing.

Blistering – Bubbles or pimples that appear on the surface of asphalt roofing due to moisture or improper installation.

C

Chimney Cap – A protective cover that prevents rain, debris, and animals from entering the chimney.

Cladding – The application of one material over another to provide a skin or layer and used in construction to provide a degree of thermal insulation and weather resistance.

D

Dormer – A structural element of a building that protrudes from the plane of a sloping roof surface.

Drip Edge – A metal flashing or other overhanging component with an outward projecting lower edge, intended to control the direction of dripping water and help protect underlying building components.

E

Eaves – The part of the roof that overhangs the walls of the building.

EPDM – Ethylene Propylene Diene Monomer, a type of synthetic rubber used in roofing membranes.

F

Fascia: The finishing edge connected to the ends of rafters, trusses, or the area where the gutter is attached to the roof edge.

Flashing – Material used to seal and protect joints in a building from water infiltration.

G

Gable – The triangular upper part of a wall at the end of a ridged roof.

Granules – Crushed minerals applied to the surface of asphalt shingles to provide UV protection and add aesthetic appeal.

H

Hip Roof: A type of roof where all sides slope downwards to the walls, usually with a gentle slope.

HVAC: Heating, Ventilation, and Air Conditioning system, often including rooftop units.

I

Ice Dam: A ridge of ice that forms at the edge of a roof and prevents melting snow from draining off the roof.

Insulation: Material used to reduce heat loss or heat gain by providing a barrier between the inside of a building and the outside.

J

Joist: A horizontal structural member used in framing to span an open space, often between beams that subsequently transfer loads to vertical members.

Jack: A pipe cover that is used to cover roof penetrations like plumbing vents.

K

Kickout Flashing: A type of flashing that diverts water away from the roof where the eaves meet a wall.

Knee Wall: A short wall, typically under three feet in height, commonly used in attic spaces.

L

Louvers: Ventilation slats that allow air to pass through while keeping out rain and direct sunlight.

Low Slope Roof: A roof with a slope of less than 3-in-12.

M

Membrane: A flexible or semi-flexible covering, used as waterproofing on a flat roof.

Moss: A type of plant that can grow on the surface of shingles, causing damage over time.

N

Nailer: A piece of wood or metal attached to the roof deck or wall to provide a surface to which other materials can be nailed.

Neoprene: A synthetic rubber used in roofing membranes and flashing.

O

OSB: Oriented Strand Board, a type of engineered wood similar to particle board, formed by adding adhesives and then compressing layers of wood strands in specific orientations.

Overhang: The part of the roof that extends beyond the walls of the building.

P

Pitch: The steepness or angle of a roof.

PVC: Polyvinyl Chloride, a type of plastic used in roofing membranes.

Q

Quarter Round: A convex molding that is one quarter of a circle.

Quartzite: A natural stone used for decorative roofing.

R

Rafters: Structural members extending from the ridge or hip to the downslope perimeter or eave, designed to support the roof deck and its associated loads.

Ridge Vent: A type of vent installed along the ridge of a roof to allow warm, humid air to escape from the attic.

S

Shingles: A roofing material consisting of individual overlapping elements, usually flat and rectangular, laid in rows.

Soffit: The material forming a ceiling from the top of an exterior house wall to the outer edge of the roof.

T

Tear-Off: The removal of existing roofing materials down to the roof deck.

Truss: A structural framework of timbers or metal beams designed to support a roof.

U

Underlayment: A layer of material beneath the roofing material, providing a secondary layer of protection against the elements.

Uplift: The upward pressure on a roof created by wind.

V

Valley: The internal angle formed by the intersection of two sloping roof planes.

Vent: An opening allowing air to escape from the attic or roof space.

W

Waterproofing: The process of making a structure waterproof or water-resistant.

Wind Uplift: The upward force on a roof caused by wind pressure.

X

XPS: Extruded Polystyrene, a type of insulation material.

Y

Yield: The amount of material that a roofing project requires.

Z

Zoning: Regulations that control the use of land and construction within certain areas.