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Roofing Terms
If you intend to get your roof repaired or
replaced, you may want to familiarize yourself with the roofing
terms that your roofing contractor will be using during the process.
We have provided a list of definitions below:
AGGREGATE
Crushed stone, slag or water-worn gravel
that comes in a wide range of sizes. Used to surface built-up roofs.
ALGAE
Algae grows on
the roof and causes discoloration. It is particularly prevalent in
hot, humid and shady climates.
ALLIGATORING
A characteristic of asphalt which occurs
during the aging process in which the loss of volatile oils and the oxidation brought
about by solar radiation produces a pattern of cracks which resemble an alligator hide,
because of the limited tolerance of asphalt to thermal expansion or
contraction.
ARCHITECTURAL SHINGLES
(See Laminated Shingles)
ASPHALT
A dark brown to black, highly viscous,
hydrocarbon produces from the residue left after the distillation of petroleum, used
as a waterproofing agent.
BALLAST
Weight used to protect single-ply roofs or
to prevent blow off of systems which are not adhered.
BACK NAILING
The practice of nailing roofing felts to
the deck under the overlap, in addition to hot mopping, to prevent slippage of felts.
BARE SPOTS
Small areas on a roof where the top
membrane has become exposed to the elements.
BARREL ROOF
A roof design which in cross section is
arched.
BASE PLY
An asphalt-saturated and/or coated felt
installed as the first ply with 4 inch laps in a built-up roof system under the following
felts which can be installed in a shingle like fashion.
BATTEN PLATE
A formed piece of metal designed to cover
the joint between two lengths of metal edge.
BITUMEN
Any of various mixtures of hydrocarbons
occurring naturally or obtained through the distillation of coal or petroleum. (See
Coat Tar Pitch and Asphalt)
BLISTER
An enclosed raised spot evident on the
surface of a roof. They are mainly caused by the expansion of trapped air, water
vapor, moisture or other gases. Blisters on a roof may involve only the coating, one or
more plies of felt or may involve the whole membrane thickness.
BEAD
A semi-rounded strip (bead) of caulking
material.
BEAM
A heavy main support structure, steel or
wood running horizontally between columns or load bearing walls.
BOND BREAKER
A substance or a tape applied between two
adjoining materials to prevent adhesion between them.
BRAKE METAL
Sheet metal that has been bent to the
desired configuration.
BUILT-UP ROOF - BUR
A roof consisting minimally of a BUR
membrane but may also include insulation, vapor retarders and other components.
BUILT-UP ROOF MEMBRANE - BURM
A built-up roof consisting of plies or
layers of roofing felt bonded together on site with bitumen; either tar or asphalt.
BULB-TEE
A specialized steel reinforcing member
which support form boards and reinforces a gypsum deck, which when poured surrounds
the Bulb-Tee.
BUNDLE
The roofing term for a package of shingles. There are usually three
to five bundles per square. BUTTERFLY ROOF
A roof assembly which pitches sharply from
either side toward the center.
CANOPY
An overhanging roof.
CANT STRIP
A beveled support used at the intersection
of the roof deck with vertical surfaces so that bends in the roofing membrane to form
base flashings can be made without breaking the felts.
CAP SHEETS
One to four plies of felt bonded and top
coated with bitumen that is laid over an existing roof as a treatment for defective
roofs.
CEMENT, ROOFING
A general term for a variety of trowelable
mastics, asphalt or tar, which are used during roof construction and repair.
CHALK (ing)
The resulting dust which occurs on a
surface that is susceptible to Ultra Violet degradation.
CHECKING
A pattern of surface cracks running in
irregular lines. When found in the top pour of an asphalt built-up roof, is the
preliminary stage of alligatoring.
CLASS "A"
The highest fire-resistance rating for roofing as
per ASTM E-108. Indicates roofing is able to withstand severe
exposure to fire originating from sources outside the building.
CLASS "B"
Fire-resistance rating that indicates roofing
materials are able to withstand moderate exposure to fire
originating from sources outside the building.
CLASS "C"
Fire-resistance rating that indicates roofing
materials are able to withstand light exposure to fire originating
from sources outside the building. CLEAT
A device made of formed sheet metal which
is mechanically attached onto which the fascia flange of a metal edge is
snapped, so as to protect against wind uplift.
COAL TAR PITCH (Tar)
A bituminous material which is a by product
from the coking of coal. It is used as the waterproofing material for tar and gravel
built-up roofing.
COATING
A layer of any brush consistency product
spread over a surface for protection.
COLD APPLIED
Products that can be applied without
heating. These are in contrast to tar or asphalt which need to be heated to be
applied.
COLD PATCH
A roof repair done with cold applied
material.
COLLAR
A conical metal cap flashing used in
conjunction with vent pipes or stacks usually located several inches above the plane of
the roof, for the purpose of shedding water away from the base of the vent.
COMPATIBLE
Two or more substances which can be mixed
or blended without separating, reacting, or affecting either material
adversely.
COMPONENT
Any one part of an assembly associated with
construction.
COMPOSITE BOARD
An insulation board which has two different
insulation types laminated together in 2 or 3 layers.
CONDUCTOR
A pipe for conveying rain water from the
roof gutter to a drain, or from a roof drain to the storm drain; also called a leader,
downspout, or downpipe.
COOLING TOWER
A large device mounted on roofs, consisting
of many baffles over which water is pumped in order to reduce its temperature.
CORE
A small section cut from any material to
show internal composition. The core was taken from the roof to verify the
construction of the existing roof system. The deck is visable along with the insulation and
the roof membrane (see construction section). The core was then replaced and
repaired immediately with the appropriate mastic and fiberglas
reinforcing mesh.
CORNICE
A horizontal projecting course on the
exterior of a building, usually at the base of the parapet.
CORROSION
The deterioration of metal by chemical or
electrochemical reaction resulting from exposure to weathering, moisture, chemicals
or other agents or media.
CONTROL JOINT
A control joint controls or accommodates
movement in the surface component of a roof.
COPING
A construction unit placed at the top of
the parapet wall to serve as a cover for the wall.
CORRUGATED
Folded or shaped into parallel ridges or
furrows so as to form a symmetrically wavy surface.
COURSE
A single layer of brick or stone or other
building material.
CRAZING
A series of hairline cracks in the surface
of weathered materials, having a web-like appearance.
CRICKET
The evaluation of a part of a roof surface
as a means of promoting drainage of water from behind an obstacle such as
chimney.
CUPOLA
A small monitor or dome at the peak of a
pitched roof.
CURB
A short wall or masonry built above the
level of the roof. It provides a means of flashing the deck equipment.
CUTBACK
Basic asphalt or tar which has been
"cutback" with solvents and oils so that the material become fluid.
CUT OFF
A piece of roofing membrane consisting of
one or more narrow plies of felt usually moped in hot to seal the edge of insulation
at the end of a day's work.
DAVE
The name of the guy who compiled this
glossary. I'm glad you are actually reading this.
DAMPPROOFING
A process used on concrete, masonry or
stone surfaces for the purpose of repelling water. Moisture vapor readily penetrates
coatings of this type. The main purpose of dampproofing is to prevent the coated
surface from absorbing rain water while allowing is to breathe moisture vapor out
of the structure.
DEAD LOAD
The constant designed weight (of the roof)
and any permanent fixtures attached above or below.
DECK
The base surface to which a roof system is
applied.
DECKING
Structural surface to which the roofing or
waterproofing system (including insulation) is applied.
DEFLECT
To bend or deform under weight.
DEW POINT
The critical temperature at which vapor
condenses from the atmosphere and forms water.
DORMER
The house-like structure which projects
from a sloping roof.
DOUBLE TEE
Refers usually to a precast roof deck panel
poured with two fins in its underside to impart flexural rigidity.
DOWNSPOUT
The metal pipe used to drain water from a
roof.
DRAINAGE
The aspects of
the roof's design (slope, shape, layout) that determine its ability
to shed water.
DRAWING OUTLINE
A top view drawing, of a building or roof
showing only the perimeter drawn to scale.
DRAWING DETAIL
A top view drawing, of a building or roof
showing the roof perimeter and indicating the projections and roof mounted equipment,
drawn to scale.
DRIP EDGE
A device designed to prevent water from
running back or under an overhang.
DRIPPAGE
Bitumen material that drips through roof
deck joints, or over the edge of a roof deck.
DRY LAP
A term describing the absence of bitumen
between the plies of felt at the overlap in a BURM.
DRY SHEET
A ply mechanically attached to wood or
gypsum decks to prevent asphalt or pitch from penetrating the deck and leaking into
the building below.
DUCT
A cylindrical or rectangular "tube" used to
move air either from exhaust or intake. The installation is referred to as "duct
work".
EAVE
The part of a roof which projects out from
the side wall, or the lower edge of the part of a roof that overhangs a wall.
EDGE METAL
A term relating to brake or extruded metal
around the perimeter of a roof.
EFFLORESCENCE
The process by which water leeches soluble
salts out of concrete or mortar and deposits them on the surface. Also used as
the name for these deposits.
ELASTOMERIC
A general term, any of the numerous
flexible roof membranes that contain rubber or plastic.
EMULSION
In roofing, a coating consisting of asphalt
and fillers suspended in water.
END LAP
The amount or location of overlap at the
end of a roll of roofing felts in the application.
EPDM
Ethylene Propylene Diene Monomer. A single
ply membrane consistsing of synthetic rubber; usually 45 or 60 mils.
Application can be ballasted, fully adhered or mechanically attached. E.V.T. EQUI-VISCOUS TEMPERATURE
The critical temperature at which asphalt
reaches the viscosity most favorable to good adhesion when applied in a BUR.
EXPANSION COEFFICIENT
The amount that a specific material will
vary in any one dimension with a change of temperature.
EXPANSION JOINT
A device used to make up the motion of
expansion and contraction. On large roofs this provision for the movement of the
materials forming the walls, roof deck and roof covering is usually made by
deliberately separating the building into sections, and covering separation between adjacent
sections with the expansion joint to allow movement but keep out the weather.
Expansion joints, unlike control joints, penetrate through the roof deck.
EXTRUSION
An item formed by forcing a base metal
(frequently aluminum) or plastic, at a malleable temperature, through a die to
achieve a desired shape.
EYEBROW
A flat, normally concrete, projection which
protrudes horizontally from a building wall; Eyebrows are generally located above
windows.
FACADE
The front of a building. Frequently, in
architectural terms an artificial or decorative effort.
FACTORY MUTUAL FM
A major insurance agency who has
established stringent guidelines for maximum construction integrity as it relates to
fire and environmental hazards.Their specifications have become industry standards.
FASCIA
Any cover board at the edge or eaves of a
flat, sloping, or overhanging roof which is placed in a vertical position to protect
the edge of the roof assembly.
FASTENERS
A general term covering a wide variety of
screws and nails which may be used for mechanically securing various components of
a building.
FELT
A very general term used to describe
composition of roofing ply sheets, consisting of a mat of organic or inorganic fibers
unsaturated, impregnated with asphalt or coal tar pitch, or impregnated and coated with
asphalt.
FIRE WALL
Any wall built for the purpose of
restricting or preventing the spread of fire in a building. Such walls of solid masonry or
concrete generally sub-divided a building from the foundations to two or more feet
above the plane of the roof.
FISHMOUTH
A characteristic opening at the exposed lap
edge of BUR felts due to loss of bond or wrinkling of the felt.
FLAKE
A scale like particle. To lose bond from a
surface in small thin pieces. Sometimes a paint film "flakes".
FLASHING
Connecting devices that seal membrane
joints at expansion joints, walls, drains, gravel stops, and other places where the membrane
is interrupted or terminated.
FLASHING BASE
The upturned edge of the watertight
membrane formed at a roof termination point by the extension of the felts vertically
over the cant strip and up the wall for a varying distance where they are secured
with mechanical fasteners.
FLASHING, COUNTER
The formed metal secured to a wall, curb,
or roof top unit to cover and protect the upper edge of a base flashing and its
associated fasteners.
FLASH POINT
The critical temperature at which a
material will ignite.
FLASHING, THRU-WALL
Flashing extended completely through a
masonry wall. Designed and applied in combination with counterflashings, to
prevent water which may enter the wall above from proceeding downward in the wall or
into the roof deck or roofing system.
FOLDED SEAM
In sheet metal work, a joint between sheets
of metal wherein the edges of the sheets are crimped together and folded
flat.
FLAT SEAM
A seam at the junction of sheet metal roof
components that has been bent at the plane of the roof.
FLOP
Cutting of felts into strips, coating the
deck side with bitumen and placing (flopping) the felt onto the deck.
FLASHING, STEP
Individual small pieces of metal flashing
material used to flash around chimneys, dormers, and such projections along the
slope of a roof. The individual pieces are overlapped and stepped up the vertical
surface.
FULLY ADHERED
A completely attached (adhered) roof
membrane.
GABLE
The end of a building as distinguished from
the front or rear side. The triangular end of and exterior wall from the level of
the eaves to the ridge of a double sloped roof.
GAMBREL ROOF
A type of roof which has its slope broken
by an obtuse angle, so that the lower slope is steeper than the upper slope. A
double sloped roof having two pitches.
GALVANIZE
To coat a metal with zinc by dipping in
molten zinc after cleaning.
GAUGE
The thickness of sheet metal and wire, etc.
GLAZE COAT
A light, uniform mopping of bitumen on
exposed felts to protect them from the weather, pending completion of the job.
GRANULES
The mineral particles of a graded size
which are embedded in the asphalt coating of shingles and roofing.
GRAVEL
Loose fragments of rock used for surfacing
built-up roofs, in sizes varying from 1/8" to 1 3/4".
GROUT OR GROUTING
A cement mortar mixture commonly used to
fill joints and cavities of masonry. On roof decks, the joints between many types
of precast roof deck slabs are grouted with cement grout.
GUTTER
Metal trough at the eaves of a roof to
carry rain water from the roof to the downspout.
GUTTER STRAP
Metal bands used to support the gutter.
GUY WIRE
A strong steel wire or cable strung from an
anchor on the roof to any tall slender projection for the purpose of support.
GYPSUM
A hydrated sulfate of calcium occurring
naturally in sedimentary rock. In roofing, a type of lightweight deck made from this
pulverized rock.
HATCH
An opening in a deck; floor or roof. The
usual purpose is to provide access from inside the building.
HIP
The inclined
external angle formed by the intersection of two sloping roof
planes. Runs from the ridge to the eaves. HIP ROOF
A roof which rises by inclining planes from
all four sides of a building.
INCLINE
The slope of a
roof expressed either in percent or in the number of vertical units
of rise per horizontal unit of run. Also referred to as slope.
INCOMPATIBILITY
Descriptive of two or more materials which
are not suitable to be used together.
INSIDE DRAIN
A roof drain positioned on a roof at some
location other than the perimeter. It drains surface water inside the building
through closed pipes to a drainage system.
INSULATION
Material which slows down or retards the
flow or transfer of heat.
INSULATION FASTENERS
Any of several specialized mechanical
fasteners designed to hold insulation down to a steel or a nailable deck.
INSULATION VENT
A vent placed into the insulation which
extends above the BURM.
INTERLOCKING SHINGLES
Individual shingles that fasten together mechanically and provide
greater wind resistance.
INTERPLY
Between two layers of roofing felts that
have been laminated together.
IRMA
Insulated (or Inverted) Roof Membrane
Assembly. In this system the roof membrane is laid directly on the roof deck, covered with
extruded foam insulation and ballasted with stone, minimum of 1000 lbs. per square.
JOIST
A horizontally placed timber or beam set on
edge to give support to a floor or ceiling.
KETTLE
Equipment used for heating bitumen to a
flowing consistency.
KICK HOLE
A defect frequently found in perimeter
flashings arising from being stepped on or kicked. A small fracture of the base
flashing in the area of the cant.
KRAFT
A heavy water resistant paper.
LADDER, FIXED
A ladder which is permanently attached to a
building.
LAMINATED SHINGLES
These shingles have more than one layer of tabs to create extra
thickness. They are often referred to as three-dimensional or
architectural shingles because they create visual depth on a roof
and impart a custom look.
LAP
To extend one material partially over
another; the distance so extended.
LARGE FORMAT SHINGLES
Generally rectangular or hexagonal in shape, these shingles do not
have cutouts or tabs.
LEAD
A malleable metal once extensively used for
flashings.
LEAN-TO-ROOF
The sloping roof of a building addition having its rafters or
supports pitched against and supported by the adjoining wall of a
building.
LIQUID-APPLIED MEMBRANE
Generally applied to cast-in-place concrete
surfaces in one or more coats to provide fully-adhered waterproof membranes
which conform to all contours.
MANSARD ROOF
A roof which rises by inclined planes from
all four sides of a building. The sloping roofs on all four sides have two pitches,
the lower pitch usually very steep and the upper pitch less steep.
MASTIC A heavy trowel applied bitumen used for
flashings or patch work which remains elastic and pliable.
MELT POINT
The temperature at which the solid asphalt
becomes a liquid.
LIVE LOAD
The weight superimposed by snow or water or
other tangibles which lack permanency, not including the wind load, on
a roof.
LOOSE LAID
A membrane "laid loosely", i.e., not
adhered, over a roof deck or BURM.
MEMBRANE
A generic term relating to a variety of
sheet goods used for certain built-up roofing repairs and application. Also used to
describe the combination of felts and moppings of bitumen forming a single
flexible unit and waterproofing system of a BUR.
METAL EDGE
Brake metal or metal extrusions which are
secured at the perimeter of BURM to form a weathertight seal.
MIL THICKNESS
Measurement used to determine thickness of
a coating. 1 mil = .001 inch (1/1000).
MINERAL SPIRITS
A by-product of petroleum, clear in color,
a solvent for asphaltic coatings.
MINERAL SURFACED
A heavy roofing felt that has very small
granules embedded across its surface.
MODIFIED BITUMEN
Bitumen modified by special processing,
generally with the addition of SBS type rubber or atactic polypylenes (APP). Some
are non-reinforced, while others are reinforced with polyester, polyvinyl
acetate, fiberglass, polypropylene or aluminum foil.
MONITOR, SAW-TOOTH
A type of monitor characterized by sharp
angled pitches and vertical sections, usually arranged in rows much like teeth of
a saw.
MONITOR
A large structure rising above the
surrounding roof planes, designed to give light and/or ventilation to the building
interior.
MOPPING
A layer of hot bitumen mopped between plies
of roofing felt.
MOPPING, FULL
The application of bitumen by mopping in
such a manner that the surface being mopped is entirely coated with a reasonably
uniform coating.
MOPPING, SPOT
The procedure of applying hot bitumen in a
random fashion of small daubs, as compared to full mopping.
MOPPING, SPRINKLE
A special application of installing
insulation to the decks. It is done by dipping a roof mop into hot bitumen and sprinkling
the material onto the deck.
MOPPING, STRIP
The application of bitumen in parallel
bands.
MUD CRACKS
Cracks developing from the normal shrinkage
of an emulsion coating when applied too heavily.
NAILER
A piece of lumber secured to non-nailable
decks and walls by bolts or other means, which provides a suitable backing onto
which roof components may be mechanically fastened.
NON-DESTRUCTIVE
A phrase describing a method of examining
the interior of a component whereby no damage is done to the component itself.
NUCLEAR METER
A device used to detect moisture by
measuring slowed, deflected neutrons.
OIL-CANNING
The term describing distortion of
thin-gauge metal panels which are fastened in a manner restricting normal thermal movement.
ORGANIC
A term designating any chemical compound
which contains carbon and hydrogen.
OVERHANG
That part of the roof structure which
extends horizontally beyond the vertical plane of the exterior walls of a building.
OXIDIZE
To combine with oxygen in the air.
PARAPET WALL
A low wall around the perimeter of a roof
deck.
PARGE COAT
A thin application of plaster for coating a
wall.
PAVER STONES
Usually pre-cast concrete slabs used to
create a traffic surface.
PENTHOUSE
A relatively small structure built above
the plane of the roof.
PERLITE
An aggregate formed by heating and
expanding siliceous volcanic glass.
PHASE CONSTRUCTION
In roofing the practice of applying the
felt plies of the built-up roofing membrane in two or more operations, separated by a
delay of at least one day.
PHOTO-OXIDATION
Oxidation caused by rays of the sun.
PITCH
A term frequently used to designate coal
tar pitch.
PITCH PAN OR POCKET
A bottomless metal box placed on the BURM
around irregular projections. These are subsequently filled with coal tar pitch
or mastic to effect a weather tight seal.
PLY
A single course of roofing felts.
PLYWOOD
Wooden panels formed by gluing thin sheets
of wood together, with the grain of adjacent layers arranged at right angles.
POINTING
The process where joints between masonry
units, brick, etc., are filled with mortar.
POLYMER
A substance consisting of large molecules
which have been formed from smaller molecules of similar make-up.
POLYURETHANE
Any of various polymers with a urethane
base.
PONDING
A condition where water stands on a roof
for prolonged periods due to poor drainage and/or deflection of the deck.
POP RIVETS
Fasteners used to join pieces of metal that
are installed by either compressed air assisted or hand operated guns. Unique in
that they are installed from one side of the work.
POROSITY
The density of substance and its capacity
to pass liquids.
POUR COAT
The top coating of bitumen on a built-up
roof.
PRECAST
Concrete building components which are
formed and cured at a factory and then transported to a work site for erection.
PRIMER
A material of relatively thin consistency
applied to a surface for the purpose of creating a more secure bonding surface.
PROJECTION
Any object or equipment which pierces the
roof membrane.
PROTECTION BOARD
Heavy asphalt impregnated boards which are
laid over bituminous coatings to protect against mechanical injury.
PURLINS
A horizontal structural member spanning
between beams or trusses to support a roof deck.
RAGGLE BLOCK
A specially designed masonry block having a
slot or opening into which the top edge of the roof flashing is inserted and
anchored.
RAKE
The angle of slope of a roof rafter, or the
inclined portion of a cornice.
RE-COVERING
The process of covering an existing roofing system with a new
roofing system.
REFLECTIVE
A term referring to a material that has a
white or shiny metallic surface.
REGLET
A horizontal slot, formed or cut in a
parapet or other masonry wall, into which the top edge of counterflashing can be inserted
and anchored.
RE-IMPREGNATE
To replace oils and bitumen in the
components of the BURM which through weathering and oxidation, have been lost.
RE-ROOFING
The practice of removing an existing roofing system and
replacing it with a new
roofing system.
RIDGE
The uppermost, horizontal external angle formed by the
intersection of two sloping roof
planes.
ROLL ROOFING
Asphalt roofing products manufactured in roll form, either
smooth- or mineral-surfaced.
ROOF
The assembly of interacting components
designed to weatherproof and normally to insulate a buildings surface, separated
from adjacent assemblies by walls or changes in elevation.
ROOF COATING
A bituminous material, either a cutback or
an emulsion, to protect the surface of the BURM but not necessarily to re-impregnate
it.
ROOF COVERING
Shingles, tiles, etc., that protect the decking from weather.
This is the first layer of protection for your roof decking.
ROOF DECK
That component in building construction,
which forms a platform on which the remainder of the BURM components are
placed.
ROOF DRAIN
The termination or fitting at the roof of
an interior drain or leader, for draining rain water from nominally flat roofs.
ROOF SYSTEM
General term referring to the waterproof
covering, roof insulation, vapor barrier, if used and roof deck as an entity.
ROOFING PITCH
The measure of how steep the roof is, also called slope. A
steeper roof ordinarily lasts longer because of its better drainage
capabilities. RUN
The horizontal distance between the eaves
and the ridge of the roof, being half the span for a symmetrical gable roof.
SADDLE
A ridge in the roof deck, whose top divides
two sloping parts of the roof so that water will be diverted to the roof drains.
SATURATED FELT
This
asphalt-impregnated, organic-based felt is used as an underlayment
between the roof deck
and the roofing material. Saturated felt is produced in a variety of
weights.
SAW TOOTH ROOF
Where reviewed from the end, such a roof
serrated or tooth profile similar to the teeth of a saw.
SCRIM
A woven or mat-type fabric that is used as
a membrane sandwich between other material to provide reinforcement and
stretch resistance.
SCUPPER
An outlet in the wall of a building or a
parapet wall for drainage of water from a flat roof.
SELF-ADHERED EAVE AND FLASHING MEMBRANE
A self-adhering water-proofing shingle
underlayment designed to
protect against water infiltration due to ice dams or wind driven
rain. SELF-HEALING
A term used in reference to a material
which melts with the heat from the sun's rays, and seals over cracks that were earlier
formed from other causes.
SELF-LEVELING
A viscous material that is applied by
pouring. In its uncured state, it spreads out evenly.
SELVAGE
The unsurfaced strip along a sheet of roll
roofing which forms the under portion at the lap in the application of the roof
covering.
SHED ROOF
A roof having only one slope or pitch, with
only one set of rafters which fall from a higher to a lower wall.
SHEATHING
The boards of sheet type material, plywood
or asphalt saturated sheets, nailed to studding or roofing rafters as the base for
application of the roof covering.
SHINGLE-FASHION
The pattern formed by laying parallel felt
rolls with lapped joints so that one longitudinal edge overlaps the longitudinal
edge on the adjacent felts. Shingle fashion application begin at the low point
on a roof so that one ply drains water to a lower one and so on to a drain or to the
roof edge.
SHINGLES
Small units of material which are laid in a
series of overlapping rows as a roof covering on pitched roofs.
SIGN ANCHOR
A component usually formed with steel
angles which penetrates the BUR and is fastened to the deck.
SINGLE PLY
A descriptive term signifying a roof
membrane composed of only one layer of material such as EPDM, Hypalon or PVC.
SINGLE TEE
The name given to a type of precast
concrete deck which has one stiffening rib integrally cast into slab.
SITE
The physical grouping of a number of roofs
or buildings at a geographical location.
SKY DOME
A type of skylite exhibiting a
characteristic translucent plastic domed top.
SKYLIGHT
A structure on a roof that is designed to
admit light and is somewhat above the plane of the roof surface.
SLAG
A by-product of smelting ore such as iron,
lead or copper.
SLATE
A dark gray stratified stone cut relatively
thin and installed on pitched roofs in a shingle like fashion.
SLIPPAGE
It is the sliding, lateral movement between
adjacent to plies of felt along the plane of the bitumen film separating them, which
results in a randomly wrinkled appearance.
SLOPE
Incline or pitch of roof surface.
SMOOTH SURFACED ROLL ROOFING
Also termed coated felt, this smooth-surfaced roll
roofing is covered with ground talc or mica. It is used primarily as
flashing to seal the roof at intersections and protrusions, and for
providing extra deck protection at the roof’s eaves and valleys. SOFFIT
The underside of a part or member of a
building extending out from the plane of the
building walls.
SOFTENING POINT
The temperature at which a substance
changes from a hard material to a softer and more viscous material.
SPALLING
The chipping or flaking of concrete,
bricks, or other masonry where improper drainage or venting and freeze/thaw cycling
exists.
SPAN
The horizontal distance between supporting
structures such as beams, trusses or columns.
SPECIALTY-EAVES FLASHINGS
This self-adhering, polymer-modified bituminous sheet material is
designed for special flashing applications along roof eaves and in
other areas. It is used particularly in regions where ice dams and
water backups are common.
SPECIFICATION
Detailed written instructions which, when
clear and concise, explain each phase of work to be done.
SPLITTING
The formation of long cracks completely
through a roof membrane. Splits are frequently associated with lack of
allowance for expansion stresses. They can also be a result of deck deflection or change in
deck direction.
SQUARE
A term used by the roof industry to
indicate an amount of roof area equal to 100 square feet.
SPUD
The removal of gravel or heavy
accumulations of bitumen from roof membranes by means of chipping or scrapeing
STACK
A vertical pipe projecting through a BUR
that carries off smoke or gases.
STANDING SEAM
A type of joint often used on metal roofs.
STARTER STRIPS
In the construction of the BUR the narrow
strips of roofing felts, cut from standard width rolls, that are applied at the
beginning point so as to assure uniform configuration of the specified number of
plies.
STATIC LOAD
In roofing the total amount of permanent
non moving weight that is applied to given surface areas.
STRIP SHINGLES
Manufactured in both standard and metric
dimensions, these asphalt shingles are approximately
three times as long as they are wide, and are distinguished by the
number of cutouts or tabs that they have. The most common are three
tab.
STRUCTURE
The rafters
and trusses that support decking. SUBSTRATE
A part or substance which lies below and
supports another.
SUMP
A reservoir sometimes forming part of a
roof drain. A depression in the roof deck of a building at a roof and delivery it to
the drain.
TEAR OFF
A term used to describe the complete
removal of the built up roof membrane and insulation down to and exposing the roof
deck.
THERMAL INSULATION
A material applied to reduce the flow of
heat.
THERMAL MOVEMENT
The measured amount of dimensional change,
a material exhibits as it is warmed or cooled.
THERMAL SHOCK
The stress built up by sudden and
appreciable changes in temperature.
THERMOPLASTIC MATERIAL
Solid material which is softened by
increasing temperatures and hardened by decreasing temperatures.
TIE-IN
A term used to describe the joining of a
new roof with the old.
TILT-UP WALL
Cast concrete units which are preformed
which, when cured, are tilted to their vertical position and secured by
mechanical fasteners to prior erected structural steel. May be pre-cast.
TOP MOPPING
The finished mopping of hot bitumen on a
built-up roof.
TORCHING
Applying direct flame to a membrane for the
purpose of melting, heating or adhering.
TRUSS
A major supporting structure usually timber
for roof decks.
TUCK POINTING
The re-grouting of defective mortar joints
in a masonry or brick wall.
UNDERLAYMENT
Asphalt saturated felt used beneath roofing to
provide additional protection for the deck.
ULTRAVIOLET
The invisible rays of the spectrum which
are at its violet end. Sometimes abbreviated U.V.
VALLEY
A term applied to a depressed angle formed
by the meeting of two inclined slopes of a roof.
VAPOR
The gaseous form of any substance.
VAPOR RETARDER (BARRIER)
A membrane which is placed between the
insulation and the roof deck to retard water vapor in the building from entering
the insulation and condensing into liquid water.
VEINING
The characteristic lines or "stretch marks"
which develop during the aging process of soft bitumens.
VENT PIPE
A vertical pipe of relatively small
dimensions which protrudes through a roof to provide for the ventilation of gasses.
VENTILATOR
Device installed on the roof for the
purpose of ventilating the interior of the building.
VENTING
1. The process of installing roof vents in
a roof assembly to relieve vapor pressure. 2. The process of water in the insulation
course of the roof assembly evaporating and exiting via the roof vents.
VERMICULITE
An aggregate somewhat similar to perlite
that is used as an aggregate in lightweight roof decks and deck fills. It is formed
from mica, a hydrous silicate.
VERTICAL APPLICATION
Roll roofing laid parallel to the slope of
a roof.
VISCOSITY
The internal frictional resistance offered
by a fluid to change of shape or to the relative motion or flow of its parts.
WALKWAYS
Designated areas for foot traffic on roofs.
WATER STOP
A device designed to protect the exposed
edge of a partially installed BURM from water entrance.
WATERPROOFING
The process where a building component is
made totally resistant to the passage of water and/or water vapor.
WATER VAPOR
Moisture existing as a gas in air.
WEEP HOLE
A hole which allows for drainage of
entrapped water from masonry structures.
WELD
The joining of components together by
fusing. In thermoplastics, refers to bonding together of the membrane using heat or
solvents.
WIND UPLIFT
The upward force exerted by wind traveling
across a roof.
WRINKLE
A raised pattern of ridges running in a
random fashion in a BUR.
ZONOLITE
A lightweight, insulating concrete composed
of portland cement, water, and vermiculite aggregate. |
