Glossary of Roofing Terms

Essential roofing terms every homeowner should know. Our comprehensive guide explains key roofing terminology to help you make informed decisions about roof maintenance, repairs, and replacements

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.