Don’t just nod and smile when your contractor starts throwing around confusing roofing terminology! Our glossary of the most common roofing terms will help you make educated decisions regarding your roofing project, and give you confidence when it’s time to sign the check.
This guide should help you understand all the roofing terms you need, but if you want even more roofing information, we highly recommend the comprehensive GAF roofing glossary.
Roof Types
A roof’s shape plays a major role in the overall look and style of your home. It can also provide additional living space and affect how weatherproof your home is.
Two of the most common types are the gable roof and the hip roof. Both shed water and snow easily, but they are quite different aesthetically.
A gable roof is the typical triangular roof you see when kids draw a picture of a home. A gable roof points upwards towards the sky, emphasizing the vertical lines of the house. Their simple design makes them an inexpensive option.
A hip roof has slopes on all four sides, which come together to form a horizontal ridge. While a hip roof is more stable than a gable roof, it is also more expensive to build.
A shed roof slopes in a single direction. Typically shed roofs are used on buildings where one wall is taller than the opposite wall, or on a lower porch or overhang.
A gambrel roof is another two-sided roof, like a gable roof. But while a gable roof has a single slope on each side, a gambrel roof has two slopes on each side. The top slope is flatter than the bottom slope. This style of roof is a simple construction with fewer materials so it can help keep the cost of your roof down.
Mansard roofs are a hybrid between a gambrel and a hip roof. To create maximum space under the roof, the section nearest the wall rises steeply, and then the roof continues as a milder pitch towards the center. From the ground, you will only be able to see the steep section and the house will look like it is flat on top.
Both mansard and gambrel roofs provides extra living space for a garret, attic or loft. They are also simple to frame out, which means you have the flexibility to add on a garret or dormers at a later date. However, mansard roofs cost more than typical roofs because of the embellishments and details that go into them.
Most multi-bedroom homes will combine several different styles of roof. You can find more details on the different pros and cons of each roof style at the Roof Cost Estimator.
Roof Slope And Pitch: What's the difference?
While slope and pitch are sometimes used interchangeably, they are not the same thing.
Pitch measures how tall a roof is, compared to its width. In roofing terms, the pitch is the “rise” (roof height) divided by the “span” (roof width). This is usually expressed as a fraction: for a roof that has a rise of 4 feet over a span of the 24 feet, the pitch is “1 to 6,” expressed as 1/6.
Slope measures how steep the incline of a roof is. This is the amount of vertical rise, measured in inches, per every 12 inches of horizontal run. This is usually expressed as a ratio: a roof with a 4-in-12 slope rises 4 inches for every foot of horizontal distance.
Steeper roofs are generally more visually appealing and tend to last longer as they shed water much more efficiently and generally are subject to less direct U/V activity. They also leave room for second stories, gables and attic spaces, and give you more freedom to experiment with interesting siding, trim or eave styles.
However, the higher the pitch, the more square feet the roof takes up and the more materials your roof needs. Higher pitched roof may also tend to require more skilled labor to build or repair.
How Roof Slope Affects Roofing Materials
As a homeowner, the main thing to understand is that the slope of your roof (how steep the incline is) affects the interior volume of your home, how effectively water drains off your roof, the look of your home – and which roofing materials you can use!
For example, wood shake shingles can be used on steeper roofs but are not suitable on a lower pitched roof. That’s because water drains more slowly off a lower pitch, and could begin to penetrate through the wood shakes.
Parts Of A Roof
When your home is being built, the first part of your roof to go up will be the wooden frame. This creates the structure on which the rest of the roof will be built. The frame gives your roof its shape and will support the weight of all the materials used to build your roof. Some materials, such as tiles or slate, are much heavier than shingles and will require more hardy framing to support the extra weight.
Once the frame is in place, it is covered by decking. Decking is a thin piece of wood that covers the frame and creates the foundation for the rest of the roof to be built on. The most commonly used materials for decking are either plywood or orientated strand board (OSB). They provide the bulk of support for anything that hits, lands or walks on your roof.
Applied directly to the decking is the underlayment. This is the first barrier layer of your roof. The underlayment’s primary function is to help stop any moisture that has seeped past the outer roofing material on top of it.
Traditional underlayment is made of felt that is saturated with tar. However, recent innovations have introduced synthetic underlayment with special properties such as added water resistance, reduced heat absorption, or being an ice barrier.
Now for the part of the roof that you will actually see from the ground! The roofing material is where you, the homeowner, will likely focus most of your attention. This is where you choose which material to use, the style and the color. There is a lot to consider when choosing whether you want clay, composition or a metal roof (to name a few options!) such as the overall aesthetic, price and longevity. Composition roofs are the most commonly used roofing material in homes in the US, and are also the cheapest option. However, metal roofs are becoming more popular due to their many benefits, like increased durability and long lifespan.
When considering which roofing material to use for your home, cost is usually an important factor. Your roofer will most likely talk about the “price per square.” A square is 100 square feet (10 feet by 10 feet), and is a common measurement for a roof area.
The roof planes are the large, flat sections of a roof. How the planes are arranged gives each roof its distinctive style and character. Where two roof panels meet you get a ridge, a hip, or a valley.
Ridges are where two roof planes meet projecting upwards. They are generally horizontal and the highest point on your roof. Ridge vents are important as they allow warm, moist air to escape your attic. The location of the ridge is important if there are height restrictions in your locality, as the height of a home is usually measured from the ground to the ridge. For this reason, it is important to know if any height restrictions exist in your area as they may affect the design of your roof.
A hip is a place where two roof planes meet and project outward. A hip is similar to a peak, but is not at the top of your roof and is usually not horizontal.
A valley, just like its geographic namesake, is a place where two planes meet and project inward.
Water flows from multiple roof planes into the valleys, so your roof valleys will need to be covered with flashing. Flashing provides an added layer of protection from water damage in the areas of your roof that are most vulnerable to water. It is usually a thin metal sheet installed on valleys and around fixtures like chimneys, skylights, and vents. You can also use flashing to make a style choice: for example, copper flashing is often used to highlight aspects of the roof.
Another common place to put flashing is around dormers, where vertical walls meet the pitched roof. Similar to a valley, this area can collect a lot of water and requires extra protection. A dormer is a common feature on many two-story houses. It is a projection from the main plane of the roof that usually houses a window. The dormer is usually constructed to add space or natural light to the room inside.
Drip Edge And Roof Trimming
What about the edges of your roof? We can’t just let water roll off your roof and down the walls of your home, because that would cause water damage to the bricks and siding, and would cause foundational issues as water pools round the base of your home.
Drip edges (also known as eaves) are the edges of the roof that hang over the exterior walls of the house, consisting of a soffit and fascia. The eave can either be close, or tight to the wall depending on what look you want. Since the primary function of the eave is to take rainwater away from the walls and direct water into the gutters of the house, the further away it is, the better it can serve that function.
Where the eave edge of a roof extends past the exterior wall, the soffit is the horizontal underside of this extension. They tend to be perforated or have built-in vent openings to allow for attic ventilation. Soffits are usually the same design and color as your home’s siding, but can be different depending on your own personal tastes and preferences.
The fascia is the area of siding directly above the soffit. It’s the exposed board you see on the front of your roof’s overhang. Your fascia is also where the gutters are placed. The style and color of your fascia can add visual interest and give a finished look to your home.
Gutters are placed at the edges of the eaves on the fascia and are the plastic or metal troughs that take the water away from the edge of the roof. They are connected to downspouts and help direct water away from your home.
When you need a roof repair, or you’re ready for a roof replacement, please give us a call for a free inspection and estimate. We promise to always explain our roofing terminology and make sure you have complete confidence in your new roof!