Glossary

This glossary was designed to help those not directly involved in roofing with their understanding of roofing terminology. Many technical and chemical terms were not included.

Half Gable Roof: See Shed Roof.

Hand-Tabbing: Applying spots of adhesive to shingle tabs.

Hatch: A unit used to provide access to a roof from the interior of a building.

Headlap: The distance that the topmost ply of roofing felt overlaps the

undermost ply or course.

Heat Seaming: See Heat Welding.

Heat Transfer: Thermal energy going from an area of higher temperature to an area of lower temperature by conduction, convection, or radiation.

Heat Welding: Fusing the seams of separate sections of roofing material together through the use of hot air or an open flame and pressure. Also known as heat seaming.

Hem: The edge created by folding metal back on itself. Metal is hemmed for safety and strength reasons.

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

Hip Roof: A roof that rises by inclined planes on all sides of a building. The line where two adjacent sloping sides of a roof meet is called the Hip.

Hoist: A mechanical lifting device. A hoist can be hand or electrically operated.

Holiday: An area where a liquid-applied material is missing.

Honeycomb: Small voids left in concrete because the mortar failed to fill the spaces around the aggregate.

Hot: Slang for hot bitumen.

Humidity: The amount of water vapor in the air.

HVAC: Acronym for Heating, Ventilating, and Air Conditioning.

Hypalon: The trademark name for Chlorosulfonated Polyethylene (CSPE), which is a single-ply roofing material.