Roofing terms can be confusing. We know it’s unlikely you’re an expert in roofing, so it’s essential to understand the basics of what your roofing contractor is saying when they deliver a quote or provide an inspection report.
This article will get you up to speed from A to Z on terms and definitions related to roofs so that you can make informed decisions about your home’s roof replacement or repair project.
If you need a new roof for your home or are in the market for commercial roofing, it’s essential to be familiar with this terminology.
Let’s get started!
Roof system terms
- Roof deck
A roof decking, also called the sheathing, is the outside bottom horizontal board on top of the structural frame. It is made from plywood, OSB (Oriented Strand Board), or fiberboard. The material installed on the roof deck is nailed to the rafters to protect the roof from weather and pests.
- Drip edge / eaves
A drip edge is a trim piece installed at the roof edge to prevent water from running off the roof and down exterior walls. It is also known as a fascia, eaves, or eave flashing.
Eaves are usually made out of metal or plastic, installed along the roof edges before the shingles are installed.
OSB is a manufactured board made of wood strands oriented in different directions and glued together. It’s typically used as roof sheathing because it’s strong and relatively inexpensive.
- Roof gutters
Gutters are a part of your roofing installed once the roof is completed. They are typically made from aluminum, galvanized steel, or copper.
Gutters play a huge role in diverting ice and water from the home’s foundation, which protects the roof from water damage and leaks.
- Ice dam
An ice dam is a ridge of ice that forms at the edge of a roof, often caused by poor ventilation.
The dams can prevent melting snow and ice from draining off the roof, leading to water damage.
- Base flashing / Step flashing
Base flashing (also called step flashing because of the step-like way it’s placed on a vertical surface) is a metal piece installed at the base of a roof covering to prevent water infiltration.
There must be a base flashing at the lower edge of every roofing material installed over openings such as a chimney, dormer, or skylight.
The purpose of this metal piece is to divert water that strikes it away from any roof deck joints or penetrations.
- Cap flashing / Counter flashing
Cap flashing, also known as counter flashing, is a thin galvanized metal flashing placed around vertical surface objects, such as chimneys, vents, skylights, to cover the joints and seams of the membrane base flashing.
This type of metal is very durable and can withstand exposure to harsh weather conditions.
- Asphalt roof cement
Asphalt cement is a type of asphalt roofing base material combined with mineral granules, making it stronger and more durable. You can use it for both new construction and roof repair.
- Roll roofing
Roll roofing is a material made of asphalt laid in rolls to keep buildings and other structures waterproof.
This type of roofing is inexpensive to install, is waterproof and fire-resistant. It can also be easily repaired or replaced.
- Valley flashing
Valley flashing is a sheet metal flashing installed in roof valleys, which are the spaces found where two sloping roof surfaces meet.
It is used to prevent water from seeping into the roofing system and causing damage.
The flashing is typically made of copper, but we can also use other materials such as aluminum and stainless steel.
- Vent pipes
A vent pipe is a pipe that allows the flow of gases and vapors from an appliance or system to the outdoors.
A vent pipe is usually made of metal, plastic, or copper and is made in many different shapes and sizes.
Pipes passing through the roofing system must open the roof to allow air to enter and exit. Without a vent pipe opening, the pressure would build up and cause damage to the roof.
Underlayment is a roofing material placed on the roof deck to protect the roofing membrane from water infiltration and provide a secondary weathertight surface.
This type of material can be a roll of asphalt-saturated building paper, a sheet of tar paper, or another kind of weatherproofing mat.
- Laminated shingles
Laminated shingles are a type of roofing material composed of two or more layers of asphalt-saturated fiberglass.
These shingles are one of the most popular roofing materials on the market.
They are made from a layer of asphalt sandwiched between two layers of fiberglass.
This construction makes them more durable and resistant to weathering than traditional asphalt shingles.
- Asphalt roofing
Asphalt roofing is one of the most popular types of roofing for residential roofing systems. Asphalt shingles are made from a fiberglass mat coated in asphalt.
The asphalt roofing is then applied to the roof in shingle form.
Installing asphalt shingles is a standard service performed by most roofing companies.
In recent years, the popularity of asphalt shingle roofs has risen due to their low cost and their ability to last a long time.
Asphalt is a sticky, black, and highly viscous liquid or semi-solid form of petroleum.
An asphalt shingle is made from natural deposits or refined products, such as crude oil.
Many different asphalt roofing products are on the market, so it is essential to find the right one for your home.
- Starter Strip
The roof started strip is asphalt roofing applied at the eaves to fill space found under the cutouts and joints.
- Strip shingles
Strip shingles are a roofing material that comes in long, thin strips. They are typically made from asphalt but can also be fiberglass or metal.
These shingles are often used on homes with steep roofs, as they are more resistant to wind and rain.
Shingle tabs are the exposed portion of strip shingles defined by cutouts. They allow for the material to be applied to make it look like it has been individually installed.
The cutouts in the shingle tabs allow water to flow through and drain off of the roof, making it easier for them to last longer.
Shingle cutouts are the open portions of a strip shingle located between the tabs that contribute to the overall design of the shingle.
Cutouts may be any shape or size but are typically squares or rectangles.
- Architectural shingle
Architectural shingles are roofing materials made of asphalt and fiberglass that come in various colors designed to mimic slate or wood shakes.
They are more expensive to purchase and maintain but can last 30-50 years if properly taken care of.
- Built up roof (BUR)
This type of roof consists of several layers of asphalt and ply sheets that work together to keep water out and provide weather protection, making it an ideal choice for commercial roofing.
Contractor roofing terms
Attic ventilation consists of the outlet vents found on your roof ridge or soffit and all intake vents located in conditioned space, such as an attic access panel or louvered ceiling tiles.
Combining these two types of vents allows hot air to escape the attic during the summer months while allowing warmer air into the attic during the winter months.
This keeps your home comfortable in warmer weather and reduces moisture in areas where insulation has been installed over a vapor barrier which stops water vapor from escaping from within your home.
- Horizontal distance
The horizontal distance is the vertical rise measurement from one side of the roof to the other.
- Exterior grade boards
Exterior grade plywood is the type of board that covers the roof.
Each board is grooved so that when they are put together, they have a tight fit and shed rain well.
- First course of shingles
The “first course of shingles” is the first layer of shingles placed on your roof. After that, this will be the “starter course,” where at least two layers of shingles should be placed over the starter course.
- Tear Off
If your roof needs to be replaced, the first step is to remove the old roofing material down to the structural deck.
- Shingle tab
A shingle tab is the portion of the shingle exposed to the weather that sticks up over the edge of the shingle. When many shingles overlap, the shingle tabs create a water barrier.
- Hip shingles
Hip shingles are shingles with an inclined external angle formed by the intersection of two sloping roof planes that runs from the eaves’ ridge.
A roof ridge is the horizontal external angle formed by the intersection of two sloping roof planes. Ridge tiles are the tiles that run along this line.
The ridge is one of the most critical parts of your roof as it fixes all other components together, stopping water from getting through to the inside.
The ridgeline should be checked every year for damage and repaired or replaced if necessary.
- Roof plane
Roof planes are the different surfaces and shapes of a roof. For example, roofs can be shaped like triangles, gables, hips, and more. Planes define the pitch and angles of each part of the roof.
- Roof measure
We measure roofs by the number of feet in width that a roofing material will cover. This term is typically used when ordering shingles, as it is a more accurate way to order than by square footage.
The measurement of a sloping roof plane is the degree of the sloped roof incline expressed as the ratio of the “rise” divided by the “run.”
That is, for every one foot rising along the centerline of a roof, how many horizontal run feet are there?
Roof slopes vary in pitch/angle called planes.
The external angle of the roof slope is formed by intersecting two planes on your roof. Think about a triangle or pyramid: all sides do not have equal lengths, but they all must meet at each corner, making it three sides (sides=trapezoids).
- Gable roof
A gable roof is a structure with two sloping sides that form an ‘A’ shape. The gable roof can be open or closed.
A gable roof has two slopes on each side that join at a ridge called a crest and is topped with a flat section, called an apex. Gable roofs, typically drawn by children, are the most common type of roof.
- Hip roof
A hip roof is a roof where all sides slope downwards towards the center. A hip roof is different from a gable roof, with two sloping sides. The roof area is the total amount of space that the roof covers.
- Mansard roof
A mansard roof is a roof that slopes down on all four sides. It is named after the French architect François Mansart, who popularized the style in the seventeenth century.
The lower slope is usually covered in shingles or tiles, while the upper slope is generally made from metal and provides extra ventilation.
- Gambrel roof
Gambrel roofs have two slopes on it with one slope much steeper than the other.
This type of roof is often used on barns and other buildings where you need a lot of space. It is named after the Medieval word meaning a horse’s hock or leg.
- Shed Roof
A single-sloping roof, commonly with a steep pitch, is known as a shed roof. It also goes by the names skillion roof and pent roof.
This type of roof structure eliminates corners and low spots on the walls, creating a more useable area within.
A roofing project is a big undertaking, making it important to understand the basics of roofing terminology before you start. This will help you communicate better with your roofing contractor and ensure you’re getting the roofing materials you need.
We hope you found this article helpful and informative. If you have any comments, questions, or suggestions related to these roofing terms, please get in touch with us at (940) 497-2833. We’re here to assist you in any way we can.