01 May 1999
from a broom or mop in a random pattern.
Mud cracking--Surface cracking resembling a
Olefin--An unsaturated open-chain hydrocarbon
dried mud flat.
containing at least one double bond: ethylene or
Nail-type concrete anchor--A hammer-driven
fastener with spiral or annular rings that provides
Olefin plastics--Plastics based on polymers
made by the polymerization of olefins or
Nailer--Wood member bolted or otherwise
monomers, the olefins being at least 50 mass %.
anchored to a nonnailable deck or wall to
provide nailing anchorage of membrane or
One-on-one--See Phased Application.
Organic, adj.--Composed of hydrocarbons or
Nailing--(1) Exposed nailing of roofing wherein
their derivatives, or matter of plant or animal
nail heads are bare to the weather; (2)
Concealed nailing of roofing wherein nail heads
are concealed from the weather. (See also Blind
Organic coating--Coatings that are generally
inert or inhibited. May be temporary (e.g.,
slushing oils) or permanent (paints, varnishes,
Needle punched--A mechanical entanglement
of dry laid (usually cross-lapped, carded staple
fiber) webs where barbed needles achieve, in
Organic content--Usually synonymous with
multiple punches, mechanical bonding.
volatile solids in an ashing test; e.g., a
discrepancy between volatile solids and organic
Neoprene--Synthetic rubber (polychloroprene)
content can be caused by small traces of some
used in liquid or sheet-applied elastomeric
inorganic materials , such as calcium carbonate,
roofing membranes or flashing.
that lose weight at temperatures used in
determining volatile solids.
Panel clip--Independent clip used to attach roof
panels to substructure.
Nitrile rubber--A family of copolymers of
butadiene and acrylonitrile that can be
Panel creep--Tendency of the transverse
vulcanized into tough oil resistant compounds.
dimension of a roof panel to gain in modularity
Blends with PVC are used where ozone and
due to spring-out or storage-distortion.
weathering are important requirements in
Parapet--Portion of wall above the roof line.
Nondestructive testing (NDT)--Methods for
Pascal--SI unit of measure for force per unit
materials without damaging the object under
Pea gravel--Small gravel with a diameter
Nonwoven fabric--A structure produced by
approaching that of a pea. Size roughly defined
bonding or interlocking of fibers (or both) by
by ASTM D448, Number 7 or smaller.
mechanical, thermal or solvent means (or
Peak--The uppermost point of a gable.
Off-ratio mix--When the mixture of isocyanate
Penetration--The consistency of a bituminous
and resin does not conform to the
material expressed as the distance in tenths of a
manufacturer's recommended mixing ratio. The
millimetre (0.1 mm) that a standard needle or
acceptable ratio for most systems is when the