Superior Roofing Glossary


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 A

Adhere: The effect of two surfaces held together by adhesion, typically with asphalt or roofing cements in built-up roofing and with contact cements in some single-ply membranes.

Aggregate: Rock, stone, crushed stone, crushed slag, water worn gravel or marble chips used for surfacing and/or ballasting a roof system.

Aging: The effect on materials that are exposed to the environment over time.

Algae: Rooftop fungus that can leave dark stains on roofing.

Algae Discoloration: A type of roof discoloration caused by algae. Commonly called "fungus growth."

Angled Fasteners: Roofing nails and staples driven into decks at angles not parallel to the deck.

APA: American Plywood Association. Tests and sets standards for all varieties of plywoods used in the U.S.

Apron Flashing: Metal flashing used at chimney fronts.

American Method: Application of giant individual shingles with the long dimension parallel to the rake. Shingles are applied with a 3/4-inch space between adjacent shingles in a course.

ARMA: Asphalt Roofing Manufacturer’s Association. Organization of roofing manufacturers.

Asphalt: A bituminous waterproofing agent used in various types of roofing materials.

Asphalt Concrete Primer: Asphalt based primer used to prepare concrete and metal for asphalt sealant.

Asphalt Plastic Cement: Asphalt based sealant material used to seal and adhere roofing materials. Also called mastic, blackjack, roof tar, or bull.

ASTM: American Society for Testing and Materials. Organization that sets standards for a wide variety of materials, including roofing.

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B

Back-surfacing: Fine mineral matter applied to the back side of shingles to keep them from sticking.

Base Flashing: That portion of the flashing attached to or resting on the deck to direct the flow of water onto the roof covering.

Base Sheet: Bottom layer of built-up roofing.

Batt: A section of fiberglass or rock-wool insulation.

Beam: A structural member transversely supporting a load. A structural member carrying building loads (weight) from one support to another. Sometimes called a girder.

Bearing Wall: A wall that supports any vertical load in addition to its own weight.

Bird’s-mouth Cut: A cutout in a rafter where it crosses the top plate of the wall providing a bearing surface for nailing. Also called a heel cut.

Bitumen: Term commonly applied to various mixtures of naturally occurring solid or liquid hydrocarbons, excluding coal. These substances are described as bituminous. Asphalt is a bitumen.

Blistering: Bubbles or pimples in roofing materials. Usually moisture related. In shingles blisters are either moisture under the material or moisture trapped inside the material.

Blocking: Small wood pieces to brace framing members or to provide a nailing base for gypsum board or paneling.

Blow-offs: When shingles are subjected to high winds, and are forced off a roof deck.

Boot: A covering made of flexible material, which may be formed to a particular shape, used to exclude dust, dirt, moisture, etc. from around a penetration.

Brands: Airborne burning embers released from a fire.

Bridging: A method of roofing with metric-sized shingles.

Brooming: An action carried out to facilitate embedment of a ply of roofing material into hot bitumen by using a broom, squeegee, or special implement to smooth out the ply and ensure contact with the bitumen or adhesive under the ply.

Built-up Roof: A roofing composed of three to five layers of asphalt felt laminated with coal tar, pitch or asphalt. The top is finished with crushed slag or gravel. Generally used on flat or low-pitched roofs.

Buckling: When a wrinkle or ripple affects shingles or their underlayments.

Building Code: Published regulations and ordinances established by a city, county, or state prescribing design loads, procedures, and construction details for structures. Building codes control design, construction, and quality of materials, use and occupancy, location and maintenance of buildings and structures within the area for which the code has been adopted.

Bundle: A package of shingles. There are 3, 4 or 5 bundles per square.

Butt Edge: The lower edge of the shingle tabs.

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C

Camber: A slight convex curve of a surface, such as in a prestressed concrete deck.

Canopy: Any overhanging or projecting roof structure, typically over entrances or doors. Sometimes the extreme end is unsupported.

Cant: A beveling of foam at a right angle joint for strength and water run off.

Cant Strip: A triangular shaped piece of lumber used at the junction of a flat deck and a wall to prevent cracking of the roofing which is applied over it.

Cantilever: Any part of a structure that projects beyond its main support and is balanced on it.

Cap Flashing: The flashing covering over a horizontal surface to prevent water from migrating behind the base flashing.

Cap Sheet: The top layer in modified bitumen roofing.

Caulking: Material used to seal joints at intersections of different materials. Used with different types of siding to join the siding to pre-existing materials.: To fill a joint with mastic or asphalt cement to prevent leaks.

Cavity Wall: A wall built or arranged to provide an air space within the wall, with or without insulating material, in which the inner and outer materials are tied together by structural framing.

Ceiling Joist: One of a series of parallel framing members used to support ceiling loads and supported in turn by larger beams, girders or bearing walls. Can also be "roof joists."

Chalk Line: A line made on the roof by snapping a taut string or cord dusted with chalk. Used for alignment purposes.

Cement: See Asphalt Plastic Cement.

CFM: The cubic feet of air moved per minute. To determine the correct CFM rating needed, multiply attic square footage by 0.7. For example: 1500 square footage attic x 0.7 = 1050 CFM. This means you would look for a power ventilator rated 1050 CFM or higher.

Cladding: A material used as the exterior wall enclosure of a building.

Class "A": The highest fire-resistance rating for roofing as per the ASTM. This rating 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.

Closed-cut Valley: A method of valley treatment in which shingles from one side of the valley extend across the valley while shingles from the other side are trimmed two inches from the valley centerline. The valley flashing is not exposed.

Copings: The covering piece on top of a wall which is exposed to the weather, usually made of metal, masonry, or stone. It is preferably sloped to shed water back onto the roof.

Corrosion: When rust, rot or age negatively affect roofing metals.

Counter-flashing: The metal or siding material that is installed over roof-top base flashing systems.

Course: A row of shingles or roll roofing running the length of the roof. Parallel layers of building materials such as bricks, or siding laid up horizontally.

Crack: A non-linear separation or fracture occurring in a material. May be generally caused by induced stress, dimensional instability, or substrate movement. Some cracks may be more of a linear separation or fracture.

Crawlspace: A shallow space below a building, normally enclosed by the foundation walls.

Crickets: A peaked water diverter installed behind chimneys and other large roof projections. Effectively diverts water around projections.

Cupping: When shingles are improperly installed over an existing roof or are over-exposed, they form a curl or cup.

Cupola: A relatively small roofed structure, generally set on the ridge or peak of a main roof area.

Curb: A raised member used to support roof penetrations, such as skylights, mechanical equipment, hatches, etc. above the level of the roof surface.

Cure: A process whereby a material is caused to form permanent molecular linkages by exposure to chemicals, heat, pressure, and/or weathering.

Cutback: Aolvent-thinned bitumen used in cold-applied roofing adhesives, roof cements, and roof coatings.

Cutoff: A permanent detail designed to seal and prevent lateral water movement in an insulation system.

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D

Dead Level: Essentially horizontal or flat, as in a roof deck or rooftop with no intentional slope to the roof drains. Also referred to as zero (0) slope.

Deck: The substrate over which roofing is applied. Usually plywood, wood boards, or planks.

Dormer: A space which protrudes from the roof, usually including one or more windows.

Double Coverage: Application of asphalt roofing such that the lapped portion is at least two inches wider than the exposed portion, resulting in two layers of roofing material over the deck.

Double Rafter: The doubling (side by side) of the roof members to reinforce an opening in the roof for a slope-glazing installation.

Downspout: A pipe for draining water from roof gutters. Also called a leader.

Drainage: A system of gutters and drainpipes that carry water away from the foundation of a house.

Drip-edge: An installed lip that keeps shingles up off of the deck at edges, and extends shingles out over eaves and gutters, and prevents water from backing up under shingles.

Drop Outlet: Formed piece that serves as the hole from which the water travels from the horizontal section of the gutter to the downspout.

Dutch Lap Method: Application of giant individual shingles with the long dimension parallel to the eaves. Shingles are applied to overlap adjacent shingles in each course as well as the course below.

Dynamic Load: Any load which is nonstatic, such as a wind load or a moving live load.

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E

Eaves: The roof edge from the fascia to the structure’s outside wall. In general terms, the first three feet across a roof is termed the eave.

Eaves Flashing: Additional layer of roofing material applied at the eaves to help prevent damage from water back-up.

Eave Height: The vertical dimension from finished grade to the eave.

Edge Venting: The practice of providing regularly spaced or continuously protected openings along a roof edge or perimeter, used as part of a ventilation system to dissipate heat and moisture vapor.

Edging Strips: Boards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for reroofing with asphalt shingles.

Ell: An extension of a building at right angles to its length.

Embedment: The process of installing or pressing-in a reinforcement felt, fabric, mat or panel uniformly into hot or cold-applied bitumen via the force of gravity.

Embrittlement: The loss of flexibility or elasticity of a material. The transition of a flexible material to a brittle state.

Emulsion: A dispersion of fine particles or globules in a liquid.

End-laps: When installing rolled products in roofing, the area where a roll ends on a roof, and is overlapped by the next section of rolled material.

Envelope: A continuous edge seal formed at the perimeter and at penetrations. The envelope is intended to prevent bitumen seepage from the edge of the membrane.

Exposure: The area on any roofing material that is left exposed to the elements.

Exposed Nail Method: Application of roll roofing in which all nails are driven into the cemented, overlapping course of roofing. Nails are exposed to the weather.

Exhaust Ventilation: Air that is typically vented or exhausted from the roof cavity, typically through vents installed on the upslope portion of the roof. With most steep-slope roofs, exhaust vents are typically located at or near the ridge.

Expansion Cleat: A cleat designed to handle thermal movement of the metal roof panels.

Expansion Joint: A structural separation between two building elements that allows free movement between the elements without damage to the roofing or waterproofing system.

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F

Fabric: A woven cloth or material of organic or inorganic filaments, threads, or yarns used for reinforcement in certain membranes and flashings.

Fascia: A flat board that runs horizontally along the eaves of a roof, typically capping the ends of the roof rafters to give the roof edge a more finished look and provide a base for attaching gutters.

FMRC: Factory Mutual Research Corporation. A research and testing organization that classifies roofing components and assemblies for their fire, traffic, impact , weathering, and wind-uplift resistance for four major insurance companies in the United States.

Fasteners: Nails or staples used in securing roofing to the deck.

Feathering Strips: Tapered wood filler strips placed along the butts of old wood shingles to create a level surface when reroofing over existing wood shingle roofs. Also called "horsefeathers."

Felt: Organic or paper-based rolled material saturated with asphalt to serve as roofing underlayment.

FHA: Federal Housing Authority. Sets construction standards throughout the U.S.

Fiberglass Insulation: Blanket or rigid board insulation, composed of glass fibers bound together with a binder used to insulate roofs and walls.

Fiberglass Mat: fibers condensed into strong, resilient mats for use in roofing materials.

Field of the Roof: The central or main portion of a roof, excluding the perimeter and flashing.

Flange: Metal pan extending up or down a roof slope around flashing pieces. Usually at chimneys and plumbing vents.

Flashing: Pieces of metal or roll roofing used to prevent seepage of water into a building around any intersection or projection in a roof such as vent pipes, chimneys, adjoining walls, dormers and valleys. Galvanized metal flashing should be minimum 26-gauge.

Flat Roof: A type of roof, which in contrast to a sloped roof, is horizontal or nearly horizontal. Materials that cover flat roofs should allow the water to run off freely from a very slight inclination. Modern flat roofs tend to use a continuous membrane which can better resist pools of standing water.

Flashing Cement: Sealant designed for use around flashing areas, typically thicker than plastic cement.

Flue: The space or passage in a chimney through which smoke, gas, or fumes ascend.

Free-tab Shingles: Shingles that do not contain factory-applied strips or spots of self-sealing adhesive.

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G

Gable: The triangular end of a house that stretches between the eaves and the ridgeline of the roof.

Gable Vent: A vent placed in the gable of a home that increases air flow to the attic, thereby reducing heat and moisture buildup.

Gable Roof: A type of roof containing sloping planes of the same pitch on each side of the ridge. Contains a gable at each end.

Gambrel Roof: A type of roof containing two sloping planes of different pitch on each side of the ridge. The lower plane has a steeper slope than the upper. Contains a gable at each end.

Gauge: The measurement of rating metal thickness.

Glass Felt: A sheet composed of bonded glass fibers, suitable for impregnation and coating in the manufacture of bituminous roofing and waterproofing materials, and shingles.

Glass Mat: A thin mat composed of glass fibers, woven or non-woven, with or without a binder. This mat may serve as reinforcement for certain roof materials and membranes.

Glaze Coat: The top layer of asphalt on a smooth-surfaced built-up roof membrane.

Granules: Crushed rock that is coated with a ceramic coating and fired, used as top surface on shingles.

Gravel: Aggregate resulting from the natural erosion of rock.

Gravel Stop: A low profile metal edge flashing with a flange along the roof side, usually formed from sheet metal. Installed along the perimeter of a roof to provide a continuous finished edge for roofing material.

Grout: A mixture of cement, sand, and water used to fill cracks and cavities in masonry.

Gutters: Horizontal channels installed at the edge of a roof to carry rainwater or melted snow away from the house.

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H

Hand-Sealing: The method to assure sealing of shingles on very steep slopes, in high wind areas, and when installing in cold weather.

Headlap: The distance of overlap measured from the uppermost course to the point that it overlaps the undermost course.

HEX Shingles: Shingles that have the appearance of a hexagon after installation.

High Nailing: When shingles are nailed or fastened above the manufacturer’s specified nail location.

Hip: The inclined external angle formed by the intersection of two sloping roof planes. Runs from the ridge to the eaves.

Hip Legs: The down-slope ridges on hip roofs.

Hip Roof: A roof with four roof planes coming together at a peak and four separate hip legs.

Hip Shingles: Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.

Holiday: An area where a liquid-applied material is missing or absent.

Horsefeathers: See Feathering Strips.

"Hot" or "Hot Stuff": The roofer's term for hot bitumen.

HVAC: An abbreviation for Heat, Ventilation, and Air Conditioning.

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I

I-beam: A steel beam with a cross section resembling the letter "I."

Ice Dam: When a snow load melts on a roof and re-freezes at the eave areas. Ice dams force water to "back-up" a roof and cause leakage.

Impregnate: To coat, saturate, and surround the fibers of a reinforcing mat or fabric with an enveloping liquid material.

Infrared Thermography: Roof system analysis where an infrared camera is used to measure the temperature differential of a roof surface to locate areas of underlying wet or moist insulation.

Insulation: Any of a variety of materials designed to reduce the flow of heat, either from or into a building.

Interlocking Shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.

Internal Pressure: Pressure inside a building that is a function of ventilating equipment, wind velocity, openings and air leaks.

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J

Joist: One of a series of parallel beams, usually two inches in thickness, used to support floor and ceiling loads, and supported in turn by larger beams, girders, or bearing walls.

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L

"L" Flashing: Continuous metal flashing consisting of several feet of metal. Used at horizontal walls, bent to resemble an "L".

Laminated Shingles: Strip shingles containing more than one layer of tabs to create extra thickness. Also called three-dimensional shingles or architectural shingles.

Lap: The area where roll roofing or rolled underlayments overlap one another during application.

Lap Cement: An asphalt-based cement used to adhere overlapping plies of roll roofing.

Lap Seam: Occurs where overlapping materials are seamed, sealed, or otherwise bonded.

Latex: A colloidal dispersion of a polymer or elastomer in water which coagulates into a film upon evaporation of the water.

Louvre: A vented opening into a room that has a series of horizontal slats and arranged to permit ventilation but to exclude rain, snow, light, insects, or other living creatures.

Low-Slope Roof: A roof surface with a maximum slope of 2 inches of "rise" for 12 inches of "run."

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M

Mansard Roof: A type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Contains no gables.

Mats: The general term for the base material of shingles and certain rolled products.

Masonry Primer: An asphalt-based primer used to prepare masonry surfaces for bonding with other asphalt products.

Mastic: See asphalt plastic cement.

Membrane: A flexible or semi-flexible material, which functions as the waterproofing component in a roofing assembly.

Mineral Stabilizers: Finely ground limestone, slate, traprock or other inert materials added to asphalt coatings for durability and increased resistance to fire and weathering.

Mineral-surfaced Roofing: Asphalt shingles and roll roofing that are covered with granules.

Modified Bitumen: Rolled roofing membrane with polymer modified asphalt and either polyester or fiberglass reinforcement.

Mortar: Mixture of sand, mortar, limestone and water used in bonding a chimney’s bricks together.

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N

Nail Guideline: Painted line on laminated shingles, to aid in the proper placement of fasteners.

Nail-pop: When a nail is not fully driven, it sits up off the roof deck.

Nesting: A method of reroofing with new asphalt shingles over old shingles in which the top edge of the new shingle is butted against the bottom edge of the existing shingle tab.

No-cutout Shingles: Shingles consisting of a single, solid tab with no cutouts.

NRCA: National Roofing Contractors Association. Respected national organization of roofing contractors.

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O

Open Valley: Method of valley construction in which shingles on both sides of the valley are trimmed along a chalk line snapped on each side of the valley. Shingles do not extend across the valley. Valley flashing is exposed.

Organic Felt: An asphalt roofing base material manufactured from cellulose fibers.

Organic Mat: Material made from recycled wood pulp and paper.

Organic Shingles: Shingles made from organic (paper) mats.

OSB: Oriented Strand Board. A decking made from wood chips and lamination glues.

Over-driven: The term used for fasteners driven through roofing material with too much force, breaking the material.

Over-exposed: Installing shingle courses higher than their intended exposure.

Overhang: The portion of the roof that extends beyond the walls of a home. The soffit or eave is the underside of an overhang.

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P

Pallets: Wooden platforms used for storing and shipping bundles of shingles.

Parapet: The portion of an exterior wall that extends above the edge of a roof.

Penetration: Any object passing through the roof.

Pipe Boot: Pre-fabricated flashing piece used to flash around circular pipe penetrations.

Pitch: The degree of roof incline expressed as the ratio of the rise, in feet, to the span, in feet.

Pitch-Pocket: A flanged, open bottomed enclosure made of sheet metal placed around a penetration through the roof, filled with grout to seal the area around the penetration.

Plastic Cement: Asphalt based sealant. Also called bull, mastic, tar, asphalt cement.

Plumbing Vents: Term used to describe plumbing pipes that project through a roof plane. Also called vent stacks.

Ply: The number of layers of roofing: i.e. one-ply, two-ply.

Prevailing Wind: The most common direction of wind for a particular region.

Ponding: The excessive accumulation of water at low-lying areas on a roof.

Positive Drainage: The drainage condition in which consideration has been made in the design of the roof ensuring drainage of the roof area within 48 hours of rainfall.

Power Vents: Electrically powered fans used to move air from attics and structures.

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Q

Quarter-sized: Term for the size of hand sealant dabs, size of a U.S. 25¢ piece.

Quick-setting Cement: An asphalt-based cement used to adhere tabs of strip shingles to the course below. Also used to adhere roll roofing laps applied by the concealed nail method.

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R

Racking: Method of installing shingles in a straight up the roof manner.

Rake Edge: The overhang of an inclined roof plane beyond the vertical wall below it.

Random-tab Shingles: Shingles on which tabs vary in size and exposure.

Re-Cover: The addition of a new roof membrane or steep-slope roof covering over a major portion of an existing roof assembly. This process does not involve removal of the existing roofing.

Release Tape: A plastic or paper strip that is applied to the back of self-sealing shingles. This strip prevents the shingles from sticking together in the bundles, and need not be removed for application.

Ridge: The highest point on the roof, represented by a horizontal line where two roof areas intersect, running the length of the area.

Ridge Shingles: Shingles used to cover the horizontal external angle formed by the intersection of two sloping roof planes.

Ridge Vent: A vent located at the ridge that allows the escape of warm and moist air from the attic or rafter cavities.

Rise: The vertical dimension of a slope.

Roll Roofing: Asphalt roofing products manufactured in roll form.

Roof Drains: Drains installed at the low spot in a roof that channels water into a drainpipe to prevent pooling.

Roof Louvers: Rectangular shaped roof vents. Also called box vents, mushroom vents, airhawks, soldier vents.

Roof Plane: A roofing area defined by having four separate edges. One side of a gable, hip or mansard roof.

Roofer: A Craftsman who applies roofing materials.

Roofing Tape: An asphalt-saturated tape used with asphalt cements for flashing and patching asphalt roofing.

Run: Horizontal dimension of a slope.

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S

Saddle: Two sloping surfaces meeting in a horizontal ridge, used between the back side of a chimney, or other vertical surface, and a sloping roof. Used to divert water around the chimney or vertical surface.

Saturant: Asphalt used to impregnate an organic felt base material.

Saturated Felt: An asphalt-impregnated felt used as an underlayment between the deck and the roofing material.

Sawteeth: The exposed section of shingles shaped to imitate the look of wood shake.

Scuppers: Openings in a roof or parapet usually faced with metal flashing to drain water from the roof at a given point.

Self-sealant: Sealant installed on shingles. After installation, heat and sun will activate sealant to seal the shingles to each other.

Self-sealing Shingles: Shingles containing factory-applied strips or spots of self-sealing adhesive.

Self-sealing Strip or Spot: Factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.

Selvage: That portion of roll roofing overlapped by the succeeding course to obtain double coverage. Designed for nail placement and sealant.

Shading: Slight differences in shingle color that may occur as a result of normal manufacturing operations.

Shake: A wooden shingle that is made from split logs. When these are used for covering the top of a house, the result is a shake roof.

Sheathing: Exterior grade boards used as a roof deck material.

Shed Roof: A roof containing only one sloping plane. Has no hips, ridges, valleys or gables. Selvage- The non exposed area on rolled roofing. Area without granules. Designed for nail placement and sealant.

Side-laps: The area on rolled material where one roll overlaps the rolled material beneath it. Also called selvage edge on rolled roofing.

Side-walls: Where a vertical roof plane meets a vertical wall. The sides of dormers etc.

Single coverage: Asphalt roofing that provides one layer of roofing material over the deck.

Slope: The degree of roof incline expressed as the ratio of the rise, in inches, to the run, in feet.

Soffit: The exposed underside of any overhead component of a building, such as arch, balcony, or beam.

Soffit Ventilation: Intake ventilation installed under the eaves, or at the roof edge.

Soil Stack: A vent pipe that penetrates the roof.

Span: The horizontal distance from eaves to eaves.

Square: A unit of roof measure covering 100 square feet.

Square-tab Shingles: Shingles on which tabs are all the same size and exposure.

Standing Seam: A type of metal roof which consists of a series of adjacent metal panels that run vertically from the roof's ridge to the eave. The panels overlap or interlock, creating a waterproof seam. The resulting roof is lightweight and energy efficient.

Starter Strip: Asphalt roofing applied at the eaves that provides protection by filling in the spaces under the cutouts and joints of the first course of shingles. This is the first course of roofing installed. Usually trimmed from main roof material.

Step-flashing: Metal flashing pieces installed at side-walls and chimneys for weather-proofing.

Strip Shingles: Asphalt shingles that are approximately three times as long as they are wide.

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T

Tab: The bottom portion of traditional shingle separated by the shingle cut-outs.

Tapered Edge Strip: A tapered insulation strip used to (1) elevate and slope the roof at the perimeter and at curbs, and provide a gradual transition from one layer of insulation to another.

Tear-off: Removal of existing roofing materials down to the roof deck.

Tear Resistance: The load required to tear a material.

Telegraphing: When shingles reflect the uneven surface beneath them. Shingles installed over buckled shingles may show some buckles.

Top Lap: The portion of the roofing covered by the succeeding course.

Transitions: When a roof plane ties into another roof plane that has a different pitch or slope.

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U

UL: Underwriters Laboratories, Inc. An organization that tests, rates and classifies roof assemblies for their resistance to: fire, impact, leakage, corrosion of metal components, and wind uplift.

UL Label: Label displayed on packaging to indicate the level of fire and/or wind resistance of asphalt roofing.

Under-driven: Term used to describe a fastener not fully driven flush to the shingles surface.

Underlayments: Asphalt based rolled materials designed to be installed under the main roofing material to separate the roof covering from the roof deck, to shed water, and to provide secondary weather protection for the roof area of the building.

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V

Valley: Area where two adjoining sloped roof planes intersect on a roof creating a "V" shaped depression.

Vapor: Term used to describe moisture laden air.

Vapor Retarder: Any material used to prevent the passage of water vapor.

Vent: Any outlet for air that protrudes through the roof deck such as a pipe or stack. Any device installed on the roof, gable or soffit for the purpose of ventilating the underside of the roof deck.

Ventilation: The term used in roofing for the passage of air from an enclosed space.

Void: An open space or break in consistency.

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W

Warm Wall: The finished wall inside of a structure, used in roofing to determine how to install waterproof underlayments at eaves.

Waterproof: The quality of a membrane, membrane material, or other component to prevent water entry.

Waterproof Underlayments: Modified bitumen based roofing underlayments. Designed to seal wood decks and waterproof critical leak areas.

Waterproofing: Treatment of a surface or structure to prevent the passage of water.

Woven Valleys: Method of valley construction in which shingles from both sides of the valley extend across the valley and are woven together by overlapping alternate courses as they are applied. The valley flashing is not exposed.

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