Roofing Definitions

Types of Roofing Materials

3-Tab Shingle: A 3-tab shingle is distinguished by three uniform cutouts, or tabs, made along the lower edge of the shingles. “Each shingle looks like three separate pieces when installed, but it's only one,

Laminate Shingle: A laminated shingle is a stronger, denser version of a 3-tab asphalt shingle. It has multiple layers, uses a thicker and heavier fiberglass base mat, and the surface contains ceramic-coated minerals encased in water-resistant, high-quality asphalt.

TPO: TPO (thermoplastic polyolefin) is a single-ply white membrane used in both commercial and residential roofing. Due to TPO being a white membrane, it reflects heat instead of absorbing it.

EPDM: EPDM is an extremely durable synthetic rubber roofing membrane  (ethylene propylene diene terpolymer) widely used in low-slope buildings in the United States and worldwide.

SBS: SBS modified bitumen roofing is a material made out of asphalt and synthetic rubber, making it an exceptionally flexible material for flat roofs. Thanks to its rubber composition, the material is less prone to cracking and sustaining damage from elements like ice and sun.

APP: The APP membrane, short for Atactic Polypropylene Membrane, is a special waterproofing material that is manufactured from Bitumen. They comes in rolls.

Built Up Roofing System: Built-Up Roofing, or BUR for short, first appeared around the mid 1800's. It is a roofing system where multiple layers of asphalt get applied between ply sheets (or felts) over the roof deck and insulation.

Mod Bit: Mod bit - Modified bitumen- Peel and Stick- Cap sheet/base sheet is thought of as the evolutionary cousin of the built-up roofing systems (BUR) that have been used on low-slope roofs for more than 100 years. It is made of asphalt combined with polymerized rubber or plastic, then reinforced with fiberglass to create a rugged-yet-flexible waterproof membrane.  Not to be confused with similar materials like asphalt roll roofing, EPDM, or TPO, modified bitumen combines hot asphalt with plastic and rubber additives. They are then layered between sheets of SBS or APP.

Torch Down Roofing: AKA “torch on roofing”- is one of the most common types of roofing for flat and slightly sloped roofs. Torch down roofing consists of multiple modified bitumen membranes, applied with a propane torch. This installation process gives torch down roofing a uniquely watertight seal, making it a great choice wherever water damage is a serious concern.

Parts of a Roof

Dormer: This is a roof feature that projects out from the roof face. It usually houses a window and adds extra space and/or light to the room inside.

Abutment: This is a spot where the roof face meets the wall of the home, instead of a roof ridge. Abutments are common on small home additions, such as door canopies, bay windows, attached sheds or garages.

Gable: This is the triangular wall underneath where two roof planes meet. It’s important to note that not all roofs have gables.

Hipped End: The hipped end of the roof is the sloped roof face between two roof hips. A pyramid roof has four hipped ends. A hipped roof has only two hipped ends.

Gable End: The gable end of the roof is the edge of a roof above the gable.

Ridge: The top edge of two intersecting sloping roof surfaces (ridges will always run parallel with ground)

Hip: Like a ridge, but the intersection of two slopes meets at a pitch and are not parallel with ground.

Eave: Edge of roof that runs parallel with ground and hangs over the edge of the exterior wall

Rake: Edge of roof that is sloped/ intersecting 

Valley: Valley: This is where two pitched roof faces connect and project inward. They are always at a lower slope than the adjoining roof planes.

Soffit: Many roof styles include a soffit. When the eave edge of a roof extends past the exterior wall, the soffit is the horizontal underside of this extension. Often, soffits are perforated or have built-in vent openings to provide ventilation for the attic space. Soffit vents, coupled with ridge vents at the top of the roof, can be a very effective way to achieve proper roof ventilation.

Fascia: A fascia is the topmost vertical component of the exterior where it meets the roof edge. The roofing professional places the drip edge at the edge of the roof deck, and the rain gutter is attached to the fascia.

Gable Cornice Return: Where the horizontal cornice of a roof connects to the rake of a gable

Roofing Materials

Sheathing: Sheathing: the wood that the shingles are nailed into

Pipe Jack: cylindrical pipe

Fasteners:  It is common to use a 1 ¼” coil roofing nail for installation. Staples are typically not permitted. Nails must penetrate the roof deck by ¼” no matter what. (Let your clients with open soffits know before you start that they may have shingles poking through underneath any overhangs that have shingles on top). Shingles are typically installed with a 6-nail “snake bite” pattern to ensure they are properly fastened to the roof deck.

Staples: The type of fastener used to fasten the shingles is especially important in resisting wind uplift and pull-through. The crown of a staple is what holds a shingle in place on the eaves and on open soffits only for all Prowest jobs. You can be back charged if done incorrectly. 

Sealant: Adhesive/Sealant- Sealants protect the roof from severe weather such as rain, snow, and heat. Over time, storms and extreme sun can cause damage, leading to leaks and other issues.

Ridge Vent: A ridge vent is an air exhaust vent installed on the peak of a roof. When installing this vent, an air slot is first cut in the roof deck at the roof's peak. This air slot is then covered by the ridge vent itself. They help provide continuous, uniform exhaust ventilation at the highest portion of the attic and are designed to help resist wind-driven rain and snow, insects, and debris infiltration. Ridge cap shingles are then typically installed over the ridge vent to protect it and provide a clean finished look on the roof. 

Vents: Roof vents are openings in the top of a house that provide ventilation to the lower levels of the home and release low-pressure air that accumulates under the shingles. 

Plumbing Vents: The plumbing vent provides ventilation for your home’s plumbing. It must have special flashing where it meets the roof.

Skylights: Some skylights manufacturers include built-in flashing with their product, especially for deck-mounted skylights or those that are installed right on the roof deck. If the skylight does not come with built-in flashing, the roofing professional will need to add flashing around it. 

Self-flashed / deck mount: the self-sealing of the penetration as the mounting gets fastened to the roof.  Self flashed and deck mounted skylights are installed directly onto the decking of the roof. They are typically used for new cuts in because they must fit the rough opening exactly.

Curb Mount: Rooftop curbs are raised metal frames designed for mounting structures safely to your roof. The frames are used for accessories that mount above the roof and those that penetrate the roof's surface. A properly installed roof curb ensures that the accessory has a level platform for attachment.

OSB: oriented strand board.  is a type of engineered wood similar to particle board, formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations.

Protective Layering

Flashing:   Flashing refers to thin pieces of impervious material installed to prevent the passage of water into a structure from a joint or as part of a weather resistant barrier system. (Roof to wall/ transition Ac/ Skylight/ Chimney

Drip Edge: A metal flashing that is installed at the edges of the roof to help control the flow of water away from the fascia and to protect the underlying roofing components When water reaches the eave edge of a roof, it meets the drip edge, also called the eaves flashing. This is a thin metal strip that directs the water into the gutters. In most cases, the roofing professional should install the drip edge before the underlayment on the eaves and after the underlayment on rake edges. Without a drip edge, water may not properly drain and could flow down the wall surface and “wick” or absorb into the exposed edge of the wooden decking. This can rot out the edge of your roof, potentially leading to more problems.

Counter-flashing: The preferred method to seal a roof penetration is to use a counter-flashing to extend over the outside of the base flashing. The base flashing is installed around the object being sealed and its base flange is roofed into the roofing system. A counter-flashing, typically in the shape of a cap, or upside-down pan, is installed over the base flashing and extends down 2” or more, shedding water to the outside and onto the roofing. Counter-flashing caps are typically secured by screws with neoprene washers installed through the side legs of the cap as shown in Figure 2. Skylights and roof curbs are typically installed in this manner. 

Roof Jack: The roof jack system is what’s used to seal penetration from the roof. Sometimes people refer to it as flashing.

Underlayment: is a fabric-like barrier, traditionally made of asphalt-saturated felt, but now commonly available as a synthetic. It’s applied directly to the decking and serves a few different functions. Underlayment protects the shingles from any resin the decking may release and serves as a water barrier in case water gets beneath the shingles. It also offers some fire resistance.

Ice and Water Shield: Also known as a base sheet, is needed to prevent water leakage in vulnerable areas.  

It is a self-adhering waterproofing underlayment that is installed beneath the shingles. This material helps defend a roof from ice dams and wind-driven rain, which can drive water up between shingles. Installed at the eaves and rakes, in valleys, & around chimneys, etc. In some climates, it makes sense to use an ice and water protector over the entire roof deck, particularly in high-wind and hurricane-prone areas of the country. However, if the attic does not have proper ventilation, the ice and water protector could make them worse. Even in climates with less severe weather conditions, ice and water protectors can provide an added water barrier for vulnerable areas of the roof, like valleys or the roof’s edge, or around roof features like skylights.

Other Roofing Terms

Decking: The entire roof frame is covered in a thin piece of wood called decking or roof sheathing. Roof sheathing material is usually plywood or oriented strand board (OSB) that is half an inch. Decking is supported by the roof frame. Unless the roof code calls for something different.

Truss: Serves as the roof’s skeleton, which the other parts of the roof will all rest on. There are various national and local construction codes that dictate the structure of your roof frame. In this article, we will focus on the parts of the roof above the roof frame.

Trim: Trim (AKA shingle mold) – is the piece of decorative trim piece at the top of the fascia that matched the roof line. 

High Roof: Defined as 2 stories or more

Roof Slope: Roof slope is the incline of the roof. It is expressed as a ratio of vertical rise to horizontal run, and tells you how many inches the roof rises for every twelve inches in depth. The higher the rise, the steeper the roof is. The measurement ratio is always expressed as inches per foot. For example, a roof that rises six inches for every foot, it would be written as 6:12. Typically, the most common roof slopes will be referred to as flat, low-slope, medium-slope, and steep-slope.

SQ's: In roofing, 100 Square Feet (10’ x 10’) = 1 SQ. (ex: A 3,033 SF roof would be 30.33 SQ’s in roofing terminology)

Roof Plane: Roof plane: This is the surface of the roof. It is flat but pitched or on an angle. It is also called the field of the roof.

Roof Styles