The more advanced terms used in roofing are sometimes more than confusing if you don’t work in the industry.

Learning a few of the more difficult terms is necessary in order to understand what your contractor is trying to describe to you.

Reviewing and learning some of these more advanced terms prior to visiting with your roofing contractor will help you to understand what it is that he is trying to describe to you and exactly what it is that you need to have done when your roof is under construction.

Algae discoloration - Type of roof discoloration caused by algae. Usually called fungus.

Back surfacing - A very finely ground mineral material that is applied to the back of a shingle to keep it from sticking to another shingle.

Built-up roof - Flat or low-sloping roof that is made of many layers of asphalt and sheets.

Coating - Layer of thick asphalt applied to the base material in which granules or other surfacing is embedded.

Collar - flange that sits over a vent pipe to seal the roof around the opening.

Concealed-nail method - Applying rolled roofing in such a way that all nails are driven into the underlying course of roofing and covered by a cemented overlapping course.

Condensation - warm, moisture-laden air comes in contact with a cold surface leaving a thin layer of water.

Counter flashing - flashing that is attached to the vertical aspect of a surface to prevent water from getting behind the flashing.

Deck - Surface, installed over the supporting framing members, to which the roofing is applied.

Dormer - Framed window unit projecting through the sloping plane of a roof.

Double coverage - Application of asphalt roofing so that lapped portion is at least 2 inches wider than the exposed portion, resulting in two layers of roofing material over the deck.

Drip edge - A non-staining material used along the eaves and.

Edging strips - Boards nailed along eaves and rakes after pulling back existing wood.

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.

Flashing - Pieces of metal or roll roofing used to prevent seeping of water into a building around any intersection or projection in a roof, such as vent pipes, chimneys, adjoining.

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

Gutter - Trough that channels water from the eaves to the downspouts.

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.

Mineral stabilizers - Finely ground limestone, slate, trap rock 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.

Nesting - Method of re-roofing with new asphalt shingles over old.

Open valley - Method of construction where the shingles on both sides of the valley are trimmed along a chalk line snapped on each.

Organic felt - Asphalt roofing base material manufactured from cellulose fibers.

Organic shingle - Shingle primarily manufactured from wood pulp.

Overhang - portion of the roof structure that extends beyond the outside walls.

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

Racking - Roofing where the shingle courses are applied vertically up the roof rather than across and up.

Rafter - Supporting framing member right below the roof.

Selvage - That portion of roll roofing overlapped to obtain double coverage.

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

Standing Seam - A type of metal roofing system.

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 - Method of installing asphalt shingles on roof slopes.

Underlayment - Asphalt-saturated felt used beneath.

Vent - Any outlet for air that comes out through the roof, such as pipe or stack
(definitions are adapted from Sundance Roofing)