International Building Code 1502.1
General. The following words and terms shall, for the
purposes of this chapter and as used elsewhere in this code,
have the meanings shown herein.
BUILT-UP ROOF COVERING. Two or more layers of felt
cemented together and surfaced with a cap sheet, mineral
aggregate, smooth coating or similar surfacing material.
INTERLAYMENT. A layer of felt or nonbituminous saturated
felt not less than 18 inches (457 mm) wide, shingled
between each course of a wood-shake roof covering.
MECHANICAL EQUIPMENT SCREEN. A partially
enclosed rooftop structure used to aesthetically conceal heating,
ventilating and air conditioning (HVAC) electrical or
mechanical equipment from view.
METAL ROOF PANEL. An interlocking metal sheet having a
minimuminstalledweather exposure of 3 square feet (0.279m2)
METALROOFSHINGLE. An interlocking metal sheet having
an installed weather exposure less than 3 square feet (0.279
m2) per sheet.
MODIFIED BITUMEN ROOF COVERING. One or more
layers of polymer-modified asphalt sheets. The sheet materials
shall be fully adhered or mechanically attached to the substrate
or held in place with an approved ballast layer.
PENTHOUSE. An enclosed, unoccupied structure above the
roof of a building, other than a tank, tower, spire, dome cupola
or bulkhead, occupying not more than one-third of the roof
POSITIVE ROOF DRAINAGE. The drainage condition in
which consideration has been made for all loading deflections
of the roof deck, and additional slope has been provided to
ensure drainage of the roof within 48 hours of precipitation.
REROOFING. The process of recovering or replacing an
existing roof covering. See “Roof recover” and “Roof replacement.”
ROOF ASSEMBLY. A system designed to provide weather
protection and resistance to design loads. The system consists
of a roof covering and roof deck or a single component serving
as both the roof covering and the roof deck. A roof assembly
includes the roof deck, vapor retarder, substrate or thermal barrier,
insulation, vapor retarder and roof covering.
ROOF COVERING. The covering applied to the roof deck
for weather resistance, fire classification or appearance.
ROOF COVERING SYSTEM. See “Roof assembly.”
ROOFDECK. The flat or sloped surface not including its supporting
members or vertical supports.
ROOF RECOVER. The process of installing an additional
roof covering over a prepared existing roof covering without
removing the existing roof covering.
ROOF REPAIR. Reconstruction or renewal of any part of an
existing roof for the purposes of its maintenance.
ROOFREPLACEMENT. The process of removing the existing
roof covering, repairing any damaged substrate and installing
a new roof covering.
ROOF VENTILATION. The natural or mechanical process
of supplying conditioned or unconditioned air to, or removing
such air from, attics, cathedral ceilings or other enclosed spaces
over which a roof assembly is installed.
ROOFTOP STRUCTURE. An enclosed structure on or
above the roof of any part of a building.
SCUPPER. An opening in a wall or parapet that allows water
to drain from a roof.
SINGLE-PLY MEMBRANE. A roofing membrane that is
field applied using one layer of membrane material (either
homogeneous or composite) rather than multiple layers.
UNDERLAYMENT. One or more layers of felt, sheathing
paper, nonbituminous saturated felt or other approved material
over which a steep-slope roof covering is applied.