Understanding the Anatomy of a Roof
At Elevated Roofing, we are on a mission to help our clients understand as much as possible about the anatomy of a roof. Transparency is important. It’s just one of the ways we build trust.
If you know about the anatomy of a roof and how roofs work, then you will be an informed consumer- whether your roof needs a repair, or you need a roof replacement. You may also be more inclined to make sure to have your annual roof inspected when you understand the anatomy of a roof.
Anatomy of a Roof: Beneath the Shingles
Your roof may seem simple enough, but the anatomy of a roof is more complex than some people realize. When built properly, a roof is composed of layers of different materials that come together to protect your home against the elements.
Anatomy of a Roof: Important Terms
Let’s first go over some definitions of important parts that make up the anatomy of a roof.
- Eave: The eave is the lower border that overhangs the wall of your home.
- Gable: When it comes to roofing, the term “gable” has two definitions. A gable is a type of roof, but the gable is also a part of the anatomy of a roof too. It is the part of the roof that makes a triangle at the end of a building.
- Ridge: A ridge is where the roof comes to a peak at the intersection of two roof planes. A ridge runs horizontally. When looking at the anatomy of a roof, you should not confuse a ridge with a hip.
- Hip: A hip, in the anatomy of a roof, is also where two planes of the roof intersect, but instead of running horizontally, it is at an angle.
- Dormer: The dormer is the structure that projects out through a sloping roof that usually features a window.
- Valley: A valley is the part of the anatomy of a roof where two sloping roofs intersect at an angle. If your home is a rectangle and there are no dormers, the anatomy of your home may not include a valley.
- Flashing: The flashing is the water protection material that is used in areas of the roof where two roof planes intersect or at openings of a roof, such as vents or a chimney.
- Drip Edge: This is the part of the anatomy of a roof that is used at both the rake and the eave to help water drip off the roof without getting backed up into your home through the underside of the roof material.
- Decking: The decking is the part of the anatomy of a roof that is the actual base of the roof. It’s the material that makes up the planes of the roof. It’s made of planks of wood, plywood, or oriented strand board (OSB). It’s also known as the sheathing.
- Underlayment: When you look at the anatomy of a roof during installation and see a layer of felt that is saturated with asphalt or a layer of a synthetic barrier attached to the decking of the roof, that is the underlayment. There are various types of underlayment, but the important thing to remember is that it is a critical layer of protection that is attached to the decking.
Anatomy of a Roof: The Layers
Anatomy of a Roof Layer 1: Decking Material
Sitting directly above the rafters is the roof decking (or sheathing). If your home is older, the sheathing could be constructed from wood planks. In newer roofs, this is made of plywood or OSB. At the start of a roof replacement in Dallas, your team of roofing installers at Elevated Roofing will replace any damaged decking.
Roof-deck thickness requirements depend on the roof structure, applicable building codes, and the materials being used. If your home is older, it may require thicker decking material either to ensure flushness or if the rafters are widely set. Standard sheets of plywood are 4′ x 8′, but we can also cut boards to size when 4′ x 8′ sheets are too large for an area. FORTIFIED standards include specific roof-deck fastening requirements that vary by designation and application.
Anatomy of a Roof Layer 2: Leak Barriers
After the decking is replaced as needed, your team of roofers from Elevated Roofing will install leak barriers and cover all the decking with a high-quality felt underlayment. These leak barriers will help prevent water from entering the most vulnerable areas of the anatomy of a roof, such as the valleys, skylights, vents, and eaves.
Anatomy of a Roof Layer 3: Redirecting Water
Next, your roofing team will install specialized materials to help divert water away from critical areas of the roof, such as where a plane meets a vertical surface; around roof features like vents, skylights, and chimneys; or along the edges. This layer of the anatomy of a roof is meant for redirecting water and includes continuous flashing, valley flashing, kickout flashing, jack boots, drip edges, and many other components.
Anatomy of a Roof Layer 4: The Top Layer
Next, your roofing team will install the actual roofing material. If installing shingles, they will be nailed securely and properly spaced. Great care is taken to make sure the shingles overlap properly so water can drain easily off your roof.
Depending on the roof design and ventilation system, a ridge vent may be installed along the ridge for exhaust ventilation. Then, your installer will use high-grade roofing cement to seal all areas around flashing, vents, and other areas where it may be helpful to seal the area and prevent leaks.
Roof Anatomy Diagram: How to Identify the Parts of Your Roof
A roof anatomy diagram can give you a visual reference for the major roof features discussed above. We’ve created three diagrams to show the anatomy of a roof from different perspectives: the exterior features you can see, the layers beneath the roofing material, and examples of how those features can vary depending on the roof’s design.
Exterior
In this first diagram, start at the highest point and work downward.
The ridge forms the top line, while sloped sections extend toward the eaves. Hips, valleys, dormers, and roof intersections show how different planes and features shape the roof.
This roof anatomy diagram can help you identify where one section ends and another begins. It also makes it easier to describe a problem accurately to a roofer or insurance adjuster.
Instead of saying that damage is “somewhere near the top,” you may be able to point to the ridge, a valley, or another feature.
Layers
The second roof anatomy diagram shows how the layers discussed earlier fit together beneath the visible roofing material. It provides a cutaway view of the decking, underlayment, leak barriers, flashing, drip edge, shingles, and ventilation components that work together as part of the roof system.
Roof Architecture
The third roof anatomy diagram shows how the anatomy of a roof changes with different architecture. A simple gable roof has fewer intersections than a more complex roof with multiple slopes, dormers, hips, and valleys, and will therefore have a different roof anatomy and needs.
Use these diagrams as references rather than as checklists of features every home should have. Some parts shown may not appear on your roof at all, while others may be present in several locations. Comparing the diagrams with what you can see from the ground can make it easier to follow along when a roofer discusses a specific area of your roof.
Do You Need a Roof Inspection?
Knowing the anatomy of the roof is useful, but many signs of damage are not easy to spot from the ground. A professional inspection can help identify problems affecting these parts before they become more serious.
We offer a free, no-obligation roof inspection within our service area in Dallas-Fort Worth. Contact us today to have the anatomy of your roof checked for signs of damage, wear, or other issues that may need attention.
