01 May 1999
migrating through the screw hole.
heat, solvent or dielectric energy.
Seam strength--Strength of a seam of material
Roof slope--The angle a roof surface makes
measured either in shear or peel modes,
with the horizontal, measured in the number of
reported either in absolute units, e.g., pounds
inches of vertical rise in a horizontal length of 12
per inch of width--or as a percent of the sheeting
inches. (Or as a ratio such as 1:48, or as a per
Self-drilling screw--A fastener that drills and
Roofing system--An assembly of interacting
taps its own hole, used as a fastener for
components designed to weatherproof, and
attaching panels to purlins and girts.
normally to insulate, a building's top surface.
Rubber--A material capable of quickly
recovering from large deformations, normally
insoluble in boiling solvent such as benzene,
methyl ethyl ketone, and ethanol toluene
azeotrope. A rubber in its modified state retracts
within 1 mm to less than 1.5 times its original
Self-tapping screw--A fastener that forms
length after being stretched to twice its length.
receiving threads when turned into a previously
drilled hole. It is for attaching panels to purlins
Sacrificial protection--Reducing the extent of
and girts and for connecting trim and flashing.
corrosion of a metal in an electrolyte by coupling
it to another metal that is electrochemically more
active in the environment, i.e., galvanic
Saddle--A small structure that helps to channel
surface water to drains. Frequently located in a
valley, a saddle is often constructed like a small
Selvage--An edge or edging which differs from
hip roof or like a pyramid with a diamond-shaped
the main part of: (1) a fabric, or (2) granule
base (also see Cricket).
surfaced roll roofing.
Sandwich panel--A panel assembly used as
Service life--Anticipated useful life of a building,
covering; consists of an insulating core material
building component or building subsystem (e.g.,
with inner and outer skins.
Scarf--To scrap or abrade a surface to remove
Shark fin--Curled felt projecting upward through
degraded or wet polyurethane foam.
the flood coat and aggregate of a BUR
Scupper--Channel through parapet, designed
for peripheral drainage of the roof, usually a
safety overflow to limit accumulation of ponded
Shear--The force tending to make two
contacting parts slide upon each other in
opposite directions parallel to their plane of
Scrim--A woven, open mesh reinforcing fabric
made from continuous filament yarn. Used in the
reinforcement of polymeric sheeting.
Sheeting--A form of plastic or rubber in which
the thickness is very small in proportion to length
Sealant--Any material used to close up cracks
and width and in which the polymer compound is
or joints to protect against leaks. Lap sealant is
present as a continuous phase throughout, with
applied to exposed lap edges in E/P systems.
or without fabric.
Sealing washer--A metal-backed rubber washer
assembled on a screw to prevent water from