Understanding different roofing terminologies is critical to identifying the right products and warranties to use on your project. The following are definitions for some important roofing terms:
Underlayment
A layer of protection for a roofing system installed to protect the sheathing, waterproofing and/or other layers.
Weatherproofing
A protective barrier designed to keep water from passing through walls and roofs.
Drip Edge
Section of flashing that directs water dripping off the roof edge down to another surface or away from a wall.
Cripple Flashing
Fitting used along eaves or below rafters’ bottom edges; it prevents moisture intrusion into foundation wall when rainwater penetrates roof decking.
Verge Cap
Metal, stone, slate tiles or concrete pieces set above an eave’s exposed front face to protect the fascia board at an exterior corner where two roof surfaces meet.
Chimney Flash
The flashing that covers the junction of a chimney and roof to prevent water penetration into the attic. The flashing is designed to withstand heat from the fireplace without damage. It has a sloping eavestrough at its base where moisture runs off into an opening in the outer drainage plane.
Balloon Framing
A method of timber framing using curved timbers so as not to require corner posts for support, instead relying on the diagonal bracing for rigidity and strength. All posts are raked towards center between floors, creating a dome effect that minimizes structural stress under weather load.
Shake
Asphalt, wood, slate or fiberglass shingles made from wooden slats that are stapled together horizontally with tabs at each end for nailing to a roof deck. The shakes are secured in place with nails set into each tab; asphalt shakes have plastic beads embedded in the underside of each tab to help prevent leakage.
Slope
The incline or fall of a roof surface measured as a ratio expressed as rise over run: 2/12 is 1/6 inch per foot (an 8-foot section rises 24 inches); 4/12 is 2/3 inch per foot (an 8-foot section rises 16 inches).
Dormer
An exterior window structure projecting from the plane of the main roof of a house and containing one or more windows on four sides. In some region’s dormers are referred to as “balconies.”
Gable
The vertical walls at either end of a building’s façade that project outward beyond the plane of the main roof and support an overhanging upper story (or stories). The gable wall is supported by bracketing known as “trimmers” attached to the rafters.
Trim
The wood or metal molding placed along an interior or exterior wall, as on floors and steps, outside a door frame or window casing, around ceilings and over architraves of doors and windows.
Bargeboard
A board with scrolled ornamentation that is usually attached to the rake edge of a roof with no supporting brackets. The barge boards are normally placed at midpoint between adjacent gables—sometimes there’s just one barge board, sometimes two depending on architecture style.
Eaves
The ends of building roofs that extend beyond exterior walls. Eaves are protected from rain by extending above them supported by eaves moldings known as “rakes.” The lower portion of the wall beneath eaves is known as an “eave trough”; it captures water and directs it by gutters to a down pipe for collection in a rain barrel or gutter system.
Tile
A flat structural slat used as an underlayment on a roof decking material. Roof decking materials include wood shakes, asphalt shingles, slate tiles and concrete pavers. Tile helps prevent leak penetration through the roof to the interior living areas. Depending on thickness tile is waterproof rated at 5-15 PSI (pounds per square inch). Tile comes in three main types: architectural, modified bitumen and two-ply membrane.
Soffit Tray
A metal trough placed below any type of soffit near the edge of a building where water is collected. The roof drain and the downspout are placed in that trough for water flow to reach a catch basin for water collection.
Catch Basin
This series shaped sections of concrete or plastic pipe attached to the bottom of rain gutters used as a holding area for standing water (in case it rains) so that it does not spill over down spouts and cause clogging issues with your gutter system.
Downspout
A pipe through which water from property’s roofs flows down to the ground. They usually lead from the first floor, and are fixed on structures near walls or corners where they can direct run off into an exterior drain system away from foundation walls; they connect through a drainage system to a larger storm drain system.
Decorative metal shields
Decorative bands of metal placed around the base of columns or posts to prevent flanking emission and vandalism; it also creates a decorative look for the property and in some cases is used as an anti-theft device.
Chord
The edge that forms the interior angle between each member of a truss. It’s also known as “the web” of the truss, but this term is avoided because web implies something solid when, in reality, these chords are designed to be hollow rectangular tubes with holes drilled through them along their length called “diamond configuration.” This construction makes them lighter weight and cheaper to produce than solid wood members would be if used instead.
Decking
A planed wood or composite material laid over joists to form a flat floor. Common decking materials include cedar, redwood, treated pine and pressure-treated pine.
Roof Breech
The top portion of most chimneys; where smoke goes up draft is created (creates a suction opening for air to enter the chimney) when a fire burns inside in a fireplace or stove. If this area goes blocked (by ice mostly) than heat cannot escape out of the top opening; and that’s when you get backdraft which will create carbon monoxide poisoning reducing oxygen content from air trapped inside your home.
Balustrade
A series shaped construction attached to building columns, posts or walls forming a railing composed of small balusters with open spaces in between them used for safety purposes. Balustrades often decorate property by creating an ornamental look for it while preventing accidents due to falling down off balconies or stairways.
Corbeling
A method where stone slabs are placed leaning one on another as a decorative pattern used for making architectural structures and walls; the slabs are often shaped or carved in unique shapes to make it look more attractive.
