CEMP-ET
TI 809-53
01 May 1999
Phased application--The installation of a roofing
cone vertically penetrates a sample of material
or waterproofing system during two or more
under specified conditions of loading, time, and
separate time intervals; a roofing system not
temperature.
installed in a continuous operation.
Percent elongation--In tensile testing, the
Phenolic plastics--Plastics based on resins
increase in the gauge length, measured after
made by the condensation of phenols, such as
fracture of the specimen within the gauge length.
phenol and cresol, with aldehydes.
Percent water by volume--
Picture framing--A rectangular pattern of ridges
in a membrane over insulation or deck joints.
Volume of Water in Sample
= --------------------------x100
Pig spout--A sheet metal flashing designed to
Volume of Sample
direct the flow of water out through the face of
the gutter rather than through a downspout.
Percent water by weight--
Pinhole--A tiny hole in a film, foil, or laminate
Sample Weight Wet-Sample Weight Dry
comparable in size to one made by a pin.
= ------------------------------------ x100
Sample Weight Dry
Pitch--See Incline; Coal Tar Pitch; or Petroleum
Pitch.
Perlite--An aggregate used in lightweight
insulating concrete and in preformed perlite
Pitch pocket--A flanged, open bottomed
insulating board, formed by heating and
container placed around a column or other roof
expanding siliceous volcanic glass.
penetration and filled with hot bitumen, flashing
cement or pourable sealer.
Perm--(vapor transmission) Unit to measure
water vapor transmission--one grain of water
Plastic--A material that contains as an essential
vapor per square foot per hour per inch of
ingredient one or more organic polymeric
mercury pressure difference. 1 Perm = 1
substances of large molecular weight. It is solid
grain/hft2in. Hg = 5.74 x 10-11 kg/Pasm2.
in its finished state and at some stage in its
manufacture or processing into finished articles
Permeability--(1) The capacity of a porous
can be shaped by flow.
medium to conduct or transmit fluids; (2) The
amount of liquid moving through a barrier in a
Plastic cement--See Flashing Cement.
unit time, unit area and unit pressure gradient
not normalized for but directly related to
Plasticizer--Material, frequently solvent-like,
thickness; (3) The product of vapor permeance
incorporated in a plastic or a rubber to increase
and thickness (for thin films, ASTM E96--over
its ease of workability, flexibility, or extensibility.
3.2 mm (1/8 in.), ASTM C355). Usually reported
Adding the plasticizer may lower the melt
2
in perm inches or grain/hft in. Hg per inch of
viscosity, the temperature of the second order
thickness. 1 perm inch = 1.46 x 10-12 kg/Pasm.
transition, or the elastic modulus of the polymer.
Permeance--The
rate
of
water
vapor
Plasticizers--May
be
monomeric
liquids
transmission per unit area at a steady state
(phthalate esters), low molecular weight liquid
through a membrane or assembly, expressed in
polymers (polyesters) or rubbery high polymers
ng/Pasm2 (grain/ft2hin. Hg).
(EVA). The most important use of plasticizers is
with PVC where the choice of plasticizer dictates
Petroleum pitch--A dark brown to black,
under what conditions the membrane may be
predominantly aromatic, solid cementitious
used.
material obtained by the processing of
petroleum, petroleum fractions, or petroleum
Plastisols--Mixtures of resins and plasticizers
residuals.
that can be cast or converted to continuous films
D-12
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