Definition

Any substance that prevents the transmission of water vapor.

The percentage of visible light (390 to 770 nanometers) within the solar spectrum that is transmitted through glass.

Plastic plumbing pipe that carries waste water to the municipal sewage system.

A hole which allows for drainage of entrapped water from masonry or glazing structures.

Conductors for building wiring are available in AWG (American Wire Gauge) sizes ranging from No. 14 to 4/0. The larger the number size, the smaller the diameter. For example, 10 is smaller than 8. The larger the diameter of a…

Crushed stone, slag or water-worn gravel that comes in a wide range of sizes which is used to surface built-up roofs.

The rate of flow of electricity through wire - measured in terms of amperes.

A service to resolve complaints, as in NACHI's Arbitration Service.

The practice of nailing roofing felts to the deck under the overlap, in addition to hot mopping, to prevent slippage of felts.

A roof design which in a cross section is arched.