| Roof
Terms
Important Terminology for Roofing
Deck/sheathing:
The surface, usually plywood or oriented strand
board (OSB), to which roofing materials are applied.
Dormer: A small structure projecting from a
sloped roof, usually with a window.
Drip edge: An L-shaped strip (usually metal)
installed along roof edges to allow water run-off
to drip clear of the deck, eaves, and siding.
Eave: The horizontal lower edge of a sloped
roof.
Fascia: A flat board, band, or face located
at the outer edge of a rake or eave.
Felt/Underlayment: A sheet of asphalt-saturated
material (often called tar paper) used as a secondary
layer of protection for the roof deck.
Fire rating: System for classifying the fire
resistance's of various materials. Roofing materials
are rated Class A, B, or C, with Class A materials
having the highest resistance to fire originating
outside the structure.
Flashing: Pieces of metal used to prevent the
seepage of water around any intersection or projection
in a roof system, such as vent pipes, chimneys, valleys,
and joints at vertical walls.
Oriented Strand Board (OSB): Roof deck panels
(4x8 feet) made of narrow bits of wood, installed
lengthwise and crosswise in layers, and held together
with a resin glue. OSB is often used as a substitute
for plywood sheets.
Penetrations: Vents, pipes, stacks, chimneys,
and anything else that penetrates a roof deck.
Rafters: The supporting framing to which a
roof deck is attached.
Rake: The inclined edge of a roof over a wall.
Ridge: The top edge of two intersecting, sloping
roof surfaces.
Sheathing: The boards or sheet materials that
are fastened to rafters to cover a house or building.
Slope: Measured by rise in inches for each
12 inches of horizontal run. A roof with a 4-in-12
slope rises 4 inches for every 12 inches of horizontal
distance.
Square: The common measurement for roof area.
One square is 100 square feet (10 feet by 10 feet).
Truss: Engineered components that supplement
rafters in many newer homes and buildings. Trusses
are designed for specific applications and cannot
be cut or altered.
Valley: The angle formed at the intersection
of two sloping roof surfaces.
Source:
National Roofing Contractors Association.
|
