Dictionary

d
Dead Loads

Non-moving rooftop loads, such as mechanical equipment, air conditioning units, and roof deck itself.

Debris

Accumulated rubbish, trash, and fragments of roofing.

Deck

The structural surface to which the roofing or waterproofing system (including insulation) is applied.

Delamination

Separation of the plies in a roof membrane system or separation of laminated layers of insulation.

Dew Point

The temperature at which water vapor starts to condense in cooling air at the existing atmospheric pressure and vapor content.

See also: Condensation
Downspout

A pipe for draining water from roof gutters. Also called a Leader.

Drain

A device that allows for the flow of water from a roof area.

Drip Edge

A corrosion-resistant, non-staining material used along the eaves and rakes to allow water run-off to drip clear of underlying construction.