Construction Terms - Roofing 101

A

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

ASTM

American Society for Testing and Materials. A voluntary organization concerned with development of consensus standards, testing procedures and specifications.

Asphalt

A waterproofing agent applied to roofing materials during manufacturing of different roof types.

Asphalt plastic roofing cement

An asphalt based cement used to bond roofing materials. Also known as flashing cement or mastic; should conform to ASTM D-4586.

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.

Blisters

Bubbles that may appear on the surface of asphalt roofing after installation.

Brands

Airborne burning embers released from a fire.

Bridging

A method of re-roofing with metric sized shingles.

Built-up roof

A flat or low sloped roof consisting of multiple layers of asphalt and ply sheets.

Bundle

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

Butt edge

The lower edge of the shingle tabs.

C

Caulk

To fill a joint with mastic or asphalt cement to prevent leaks.

Cement

See asphalt plastic roofing cement.

Chalk line

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

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. More On Fire rating system.

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.

Coating

A layer of asphalt applied to the base material into which granules or other surfacing is embedded.

Collar

Performed flange placed over a vent pipe to seal the roof around the vent pipe opening. Also called a vent sleeve.

Concealed nail method

Application of roll roofing in which all nails are driven into the underlying course of roofing and covered by a cemented, overlapping course. Nails are not exposed to the weather.

Counter flashing

That portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.

Course

A row of shingles or roll roofing running the length of the roof.

Coverage

Amount of weather protection provided by the roofing material. Depends on number of layers of material between the exposed surface of the roofing and the deck; i.e., single coverage, double coverage, etc.

Cricket

A peaked saddle construction at the back of a chimney to prevent accumulation of snow and ice and to deflect water around the chimney.

Cutout

The open portions of a strip shingle between the tabs.

D

Deck

The surface installed over the supporting framing members to which the roofing is applied.

Dormer

A framed window unit projecting through the sloping plane of a roof.

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.

Down spout

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

Drip edge

A material used along the eaves and rakes to allow water run-off to drip clear of underlying construction.

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.

E

Eaves

The horizontal, lower edge of a sloped roof.

Eaves flashing

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

Edging strips

Boards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for re-roofing with asphalt shingles.

Ell

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

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.

Exposure I grade plywood

Type of plywood approved by the American Plywood Association for exterior use.

F

Fascia

Facing board, the vertical edge or face, located at the bottom of the roof.

Feathering strips

Tapered wood filler strips placed along the butts of old wood shingles to create a level surface when re-roofing over existing wood shingle roofs. Also called horsefeathers.

Felt

Fibrous material saturated with asphalt and used as an underlayment or sheathing paper.

Fiberglass mat

An asphalt roofing base material manufactured from glass fibers.

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.

Flashing Cement

See>asphalt plastic roofing cement.

Free tab shingles

Shingles that do not contain factory applied strips or spots of self sealing adhesive.

G

Gable

The upper portion of a side wall that comes to a triangular point at the ridge of a sloping roof.

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.

Granules

Ceramic coated, colored, crushed rock that is applied to the exposed surface of asphalt roofing products.

Gutter

The trough that channels water from the eaves to the down spouts.

H

HEX shingles

Shingles that have the appearance of a hexagon after installation.

Hip

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

Hip roof

A type of roof containing sloping planes of the same pitch on each of four sides. Contains no gables.

Hip shingles

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

Horsefeathers

See feathering strips.

I

Ice dam

Condition formed at the lower roof edge by the thawing and re-freezing of melted snow on the overhang. Can force water up and under shingles, causing leaks.

Interlocking shingles

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

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

To cover the surface of one shingle or roll with another.

Lap cement

An asphalt based cement used to adhere overlapping plies of roll roofing.

Low slope application

Method of installing asphalt shingles on roof slopes between two and four inches per foot.

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.

Masonry primer

An asphalt based primer used to prepare masonry surfaces for bonding with other asphalt products.

Mastic

See asphalt plastic roofing cement.

Mineral stabilizers

Finely ground limestone, slate, traprock or other 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.

N

Nesting

A method of re-roofing 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.

Non veneer panel

Any wood based panel that does not contain veneer and carries an APA span rating, such as wafer board or oriented strand board.

Normal slope application

Method of installing asphalt shingles on roof slopes between 4 inches and 21 inches per foot.

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.

Overhang

That portion of the roof structure that extends beyond the exterior walls of a building.

P

Pallets

Wooden platforms used for storing and shipping bundles of shingles.

Pitch

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

Ply

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

Q

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.

R

Racking

Roofing application method in which shingle courses are applied vertically up the roof rather than across and up. Not a recommended procedure.

Rafter

The supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate.

Rake

The inclined edge of a sloped roof over a wall.

Random tab shingles

Shingles on which tabs vary in size and exposure.

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 uppermost, horizontal external angle formed by the intersection of two sloping roof planes.

Ridge shingles

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

Rise

The vertical distance from the eaves line to the ridge.

Roll roofing

Asphalt roofing products manufactured in roll form.

Roofing tape

An asphalt saturated tape used with asphalt cements for flashing and patching asphalt roofing.

Run

The horizontal distance from the eaves to a point directly under the ridge. One half the span.

S

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.

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.

Shading

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

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.

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.

Smooth surfaced roofing

Roll roofing that is covered with ground talc or mica instead of granules (coated).

Soffit

The finished underside of the eaves.

Soil stack

A vent pipe that penetrates the roof.

Span

The horizontal distance from eaves to eaves.

Specialty eaves flashing membrane

A self adhering, waterproofing shingle underlayment designed to protect against water infiltration due to ice dams or wind driven rain.

Square

A unit of roof measure covering 100 square feet.

Square tab shingles

Shingles on which tabs are all the same size and exposure.

Starter strip

Asphalt roofing applied at the eaves that provide protection by filling in the spaces under the cutouts and joints of the first course of shingles.

Steep slope application

Method of installing asphalt shingles on roof slopes greater than 21 inches per foot.

Step flashing

Flashing application method used where a vertical surface meets a sloping roof plane.

Strip shingles

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

T

Tab

The exposed portion of strip shingles defined by cutouts.

Talc

See back surfacing.

Telegraphing

A shingle distortion that may arise when a new roof is applied over an uneven surface.

Three dimensional shingles

See laminated shingles.

Top lap

That portion of the roofing covered by the succeeding course after installation.

U

UL

Underwriters Laboratories, Inc.

UL label

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

Underlayment

Asphalt saturated felt used beneath roofing to provide additional protection for the deck.

W

Woven Valley

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.