| Damp proofing |
treatment of a
surface or structure to resist the passage of water
in the absence of hydrostatic pressure.
|
| Dead Level |
the term used to describe an
absolutely horizontal roof. Zero slope. (See SLOPE.) |
| Dead Level Asphalt |
a roofing asphalt that has a
softening point of 140F (60C) and that conforms to
the requirements of ASTM Standard D 312, Type 1. |
| Dead Loads |
non-moving rooftop loads, such
as mechanical equipment, air conditioning units, and
the roof deck itself. |
| Deck |
the structural surface to which
the roofing or waterproofing system (including insulation)
is applied. |
| Degradation |
a deleterious change in the chemical
structure, physical properties, or appearance of a
material due to natural or artificial exposure. |
| 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. |
| Drain |
a device that allows for the
flow of water from a roof area. |
| Dropback |
a reduction in the softening
point of bitumen that occurs when bitumen is heated
in the absence of air. (See SOFTENING POINT DRIFT.) |
