01 May 1999
Remedial roofing--The repair of selected
down roof assembly).
isolated portions of the roof system to return the
roof to uniform condition. This normally involves
Puncture resistance--Index of a material's
the removal of wet materials along with
ability to withstand the action of a sharp object
correction of the original cause of the problem.
Reroofing--The removal of all roof system
R-Factor--Resistance to heat flow.
components down to the structural deck
followed by installation of a completely new
Racking--To stretch or strain by force, such as
by the thermal or wind action.
Retrofit--the modification of an existing building
or facility to include new systems or
Rake--The sloped edge of a roof at the first or
Ridge--Highest point on the roof of the building,
a horizontal line running the length of the
Rake angle--Angle fastened to purlins at rake
for attachment of endwall panels.
Ridge cap--A transition of the roofing materials
Rake trim--A flashing designed to close the
along the ridge of a roof. Sometimes called ridge
opening between the goof and endwall panels.
roll or ridge flashing.
Re-covering--The process of covering
existing roof system with a new roof.
Ridging--An upward, tenting displacement of a
membrane, frequently over an insulation joint.
Reentrant corner--An inside corner of a surface,
where stress concentrations may occur.
Roll goods--A general term applied to rubber
and plastic sheeting, usually furnished in rolls.
Reglet--A groove in a wall or other surface
adjoining a roof surface for the attachment of
Roll roofing--Coated felts, either smooth or
Roof cement--See Flashing Cement.
waterproofing membrane reinforced with felts,
mats, fabrics, or chopped fibers.
Roof covering--The exposed exterior roof skin.
Roof curb--An accessory used to mount and
Relative humidity--The ratio of the mass per
level units (such as air conditioning and exhaust
unit volume (or partial pressure) of water vapor
fans) on the sloped portion of the building roof.
in an air-vapor mixture to the saturated mass per
unit volume (or partial pressure) of the water
Roof jack--An accessory used to cover pipes
vapor at the same temperature, expressed as a
(such as vents or flues) that penetrate the roof
Roof overhang--A roof extension beyond the
endwall/sidewall of a building.
Volume of Water in Sample
= ---------------------------------- x100
Roof seamer--Machine that crimps panels
together or that welds laps of E/P systems using
Maximum volume of water sample could hold