NCCER Roofing flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Square

A roofing unit of measure equal to 100 square feet of roof surface area. Shingle bundles are labeled by how many bundles make one square, commonly three for standard shingles.

Roof slope

The ratio of vertical rise to horizontal run, written as rise per 12 inches of run. A 6:12 slope rises 6 inches for every 12 inches of horizontal distance.

Pitch

Often used interchangeably with slope, pitch describes roof steepness. In strict carpentry terms pitch is rise over span, while slope is rise over run, so know which the plan uses.

Underlayment

A water-resistant layer of felt or synthetic sheet installed over the deck beneath the roof covering. It sheds water that gets past shingles and separates shingles from the deck.

Ice and water shield

A self-adhering waterproof membrane installed at eaves, valleys, and penetrations. It seals around nails and prevents water backup from ice dams in cold climates.

Drip edge

Metal flashing at the eave and rake edges of a roof. It directs water away from the fascia and deck edge and helps keep water from wicking back under the shingles.

Step flashing

Small L-shaped metal pieces installed in steps along a sidewall, with one leg against the wall and one over each shingle course. It sheds water at roof-to-wall intersections.

Counterflashing

Flashing embedded in or attached to a wall or chimney that overlaps the top edge of base flashing. It covers the joint and directs water onto the roof flashing below.

Valley

The internal angle where two roof planes meet. Water concentrates there, so valleys require metal flashing and careful shingle lapping, with the steeper plane shedding over the flatter.

Hip roof

A roof with sloping planes on all sides that meet at sloping ridges called hips. Hip roofs are more wind-resistant than gable roofs but generate more waste and cut pieces.

Gable roof

A roof with two sloping planes meeting at a single ridge, leaving triangular gable walls at the ends. It is simple to frame and ventilate and produces less cutting waste.

Ridge vent

A continuous exhaust vent installed along the ridge, covered by ridge cap. It works with soffit intake vents to move air through the attic by convection.

Net free vent area

The actual open area of a vent after deducting screens, louvers, and framing. Ventilation rules are calculated on net free area, not the vent's overall dimensions.

Headlap

The distance the upper shingle course overlaps the top of the course below. Headlap plus exposure equals the shingle length, and adequate headlap prevents water infiltration.

Exposure

The portion of a shingle course left exposed to weather, measured from the butt of one course to the butt of the next. It is set by the manufacturer and printed on the bundle.

Starter course

The first row of shingles installed at the eave, usually reversed or specially made. It fills the gaps between first-course tabs and seals the eave edge against wind and water.

Ridge cap

Shingles or specialized pieces bent over the ridge to cover the joint where roof planes meet. Ridge caps shed water and are often combined with ridge ventilation.

Built-up roofing

A low-slope membrane made of alternating layers of roofing felt and hot or cold bitumen, finished with a surfacing layer. Ply count determines its durability and rating.

Modified bitumen

A low-slope sheet membrane of asphalt reinforced with polymers and a fabric carrier. It is applied with adhesive, hot mopping, or torch and is common on flat and low-slope roofs.

EPDM

Ethylene propylene diene monomer, a synthetic rubber single-ply membrane for low-slope roofs. It is durable and UV-resistant and is joined with adhesive or splice tape.

TPO membrane

Thermoplastic polyolefin, a single-ply reflective membrane for low-slope roofs. Sheets are joined by heat welding, producing strong seams that resist ponding water.

Ponding

Standing water on a low-slope roof that remains more than 48 hours after rain. Ponding adds load and accelerates membrane failure, so drainage and slope must be corrected.

Roof drain

A fitting that carries water from the roof surface into the building's drainage system. It must be flashed to the membrane and kept clear of debris to prevent ponding.

Scupper

An opening through a parapet wall that lets water drain off a roof. Scuppers need flashing and must discharge where water will not damage the wall or foundation below.

Parapet

The low wall extending above the roof edge. It requires cap flashing and counterflashing at the top and base flashing where the roof membrane meets it.

Fall protection

Systems and practices that prevent falls from heights, required at 6 feet in general construction. Options include guardrails, safety nets, and personal fall-arrest systems.

Roof bracket

A temporary metal support hooked over the roof surface and nailed to structural members. It holds staging planks for workers and must be secured to framing, not just sheathing.

Decking

The structural panel surface that supports the roof covering, typically plywood or OSB. It must be thick enough for the span and fastened to resist wind uplift.

Rafter

A sloping structural member that supports the roof deck and covering, running from the ridge to the eave. Rafter size and spacing set the allowable deck span.

Fascia

The board attached to the ends of rafters or trusses at the eave. It supports the gutter and gives the roof edge a finished appearance.

Soffit vent

An intake vent installed in the soffit under the eave. It supplies low air to the attic and works with ridge or static exhaust vents to ventilate the roof.

Wind uplift

The upward force wind exerts on a roof covering. It is resisted by fastener patterns, adhesive sealant strips, and edge metal, and it increases at corners and perimeters.

Chimney flashing

A flashing system around a chimney that includes base flashing, counterflashing, and a cricket on the high side. It keeps water from entering where the roof meets the masonry.