20 Parts of a Roof (with Diagrams)

Jessica Stone
by Jessica Stone

While the foundation may be the most crucial component of a house, the roof comes in as a very close second. A house’s main purpose is to keep its occupants shielded from the elements, and the sturdy roof is what actually accomplishes that function. A quality roof will protect against wind, rain, snow cold, heat, and everything in between. Whereas, a poor or fragile roof sway in the wind, buckle in the snow, leak with excessive moisture, and be a major headache for as long as you live in the house.

Aside from adequate protection, another important reason to have a quality roof is to avoid unnecessary repairs as they can be incredibly expensive and time-consuming. In order to determine the right kind of roof to choose for your home, it’s important that you first know all of the different components involved.

From the rafters, ceiling joists, soffits, and fascia to the underlayment, battens, shingles, and gutters, knowing the different parts of a roof will help ensure that you are never plagued with a leaky roof.

In the event that you are considering installing solar panels, you may wonder: Can You Put Solar Panels On A Metal Roof?

Parts of a Roof

Understanding all of the parts that, when combined, form a roof, will allow you to make more informed decisions about roof construction and roofing repair. Though, it’s important to keep in mind that the specific roof on a home or structure may vary slightly (or considerably) from another home or structure. With that said, it’s highly likely that most, if not all, of the components on this list will be vital to your next roofing repair endeavor.

1. Truss

A truss is a wooden structure that forms a triangular shape consisting of various structural members to provide support for the roof above, while also securing the outside walls of the home together. It supports the underlayment, covering, insulations, sheathing, and all other parts that may be added to the roof, like a chimney or skylight. The truss is comprised the rafters, ridge rafters, and the like.

2. Covering

The covering is a catch-all term for any component that is secured or nailed to the rafters and contributes to keeping the elements out. It may consist of a range of materials, such as slate, iron, tile, or synthetic lining. The covering has to be lightweight and resistant to weather elements, wet leaves, dirt, and the grime that accumulates on your roof over time. The type of covering that you choose will depend on the weather where you live, the type of house you’re building, and your budget.

3. Rafters

Rafters run from one end of a roof to the other, forming the support system for the other components of the roof – from the insulation to the covering. They are usually made out of wood, since it is both strong and pliable. Though, some rafters may be made out of metal, especially those in high rises or commercial buildings.

4. Fascia

The fascia is a sheath that runs along the roof’s edges, parallel to the ground, covering the ends of the rafters. Oftentimes, it acts as a support for the gutter. Although the fascia is a relatively superficial component on roofs, many homeowners want it to be aesthetically pleasing to add to the home’s value and curb appeal.

5. Ridge

A roof’s ridge is found in specific types of roofs such as mansard, gambrel, gable, and pitched. Pitched roofs are very common among suburban homes, forming the classic upside-down ‘V’ shape. The ridge is located at the uppermost point of the roof, at the point where the two opposing sides connect. You can consider the ridge to be the ‘keystone’ of the roof.

6. Flashing

Roof flashing is a thin material, typically galvanized steel, that is used to direct water away from crucial areas of a roof. More specifically, you’ll find flashing wherever the roof plane meets a vertical surface, such as a dormer or a wall. It is also installed to surround additional roof features like chimneys, skylights, and vents.

7. Dormer

A dormer is a roofed component that vertically protrudes past the plane of a pitched roof. In most cases, dormers contain a window and are referred to as a dormer window. Dormers are often used to create window openings in a roof or to increase the usable space in a loft or attic.

8. Drip Edge

A drip edge is a type of metal flashing that is installed along the edges of the roof to help direct the flow of water away from the fascia and shield the underlying roof components. Drip edges slightly hang over the sides of the roof and feature a small metal flange that bends away from the fascia. This component is crucial to improve the overall effectiveness and extend the longevity of your roof.

9. Eaves

The eaves of a roof are the lowest points. On a pitched roof, it is the point farthest away from the roof’s ridge. The eaves are where rain drips off of the roof and, as such, is an excellent spot for placing gutters or a drip edge. This is also the last spot on the roof with shingles and is often the area where shingles will start to deteriorate from rot or peel off in inclement weather.

10. Valley

Although not every home or structure will have a roof with a valley, they are a very common component. The valley refers to the point where two pitched roofs connect and form a right angle. To the eye, it appears as a ‘V.’ Valleys are often equipped with their own gutters, as they tend to collect rainwater, leaves, and other debris.

11. Ceiling Joists

Ceiling joists run along the rafters and are almost always made out of wood. Their primary purpose is to enhance the strength of the rafters, while also providing support for the soffits.

12. Soffits

The soffit is a part of the overhang, located where the siding meets the roof. When rain hits your roof and flows away from your house with the help of the overhang. The soffit, underneath the overhang, is mainly used to insulate your home and keep the elements out. It regulates the temperature in your home by allowing the roof to “breath.” Cool, dry air enters through the soffit vent, and then hot moist air is released out of the exhaust vents in the roof.

13. Roof Sheathing

Also called roof decking, roof sheathing is the durable layer of wood boards that is attached to the roof’s trusses and ceiling joists. The sheathing is what your shingles, or another type of covering, is attached to. OSB, or oriented strand board, is currently the most-used material for roof sheathing. Both plywood and OSB have the same structural design, but OSB features small strands of wood rather than veneer sheets. Regardless, both plywood and OSB are excellent choices for roof sheathing.

14. Underlayment

The roof underlayment is placed between the sheathing (roof deck) and the shingles. It is installed directly onto the roof sheathing and serves as a secondary layer to protect and insulate against the elements. Underlayment is waterproof and may be made out of felt, rubber strips, or a synthetic material.

15. Battens

As referred to as lath, roof battens are thin strips of material that may be constructed out of metal, wood, or plastic. They are placed horizontally onto the roof before tile or shingles are laid. The main purpose of roof battens is to hold the shingles or tiles in place. How they are spaced out is crucial to ensure that the shingles or tiles are correctly and securely installed. Though, the spacing will vary based on the type of roofing.

16. Shingles

Often made out of a thick, tar-like material, shingles are resistant to rot, waterproof, and serve as the first barrier against the elements. Weight and weather resistance are the two most important considerations when it comes to choosing the right type of shingles. While you want the shingles to be as lightweight as possible, you don’t want them to give way in a storm.

While shingles may not rot, they can be prone to black streaks. What Causes Black Streaks On Roof Shingles?

17. Skylight

A skylight is an element of luxury that you may see on some homes and structures. It is essentially a window that is placed on the roof, allowing the interior of the home to be illuminated with natural lighting. However, installing a skylight can be a bit of a challenge and could lead to roof leaks if improperly installed.

18. Insulation

Insulating a roof is just as important as insulating the walls of your home, as poor roof insulation means that your house will be too cold in the winter and too hot in the summer. Found in the attic of your home, insulation appears like a thick spongy, or cotton material.

19. Downspout

Downspouts are the pipes that are connected to your gutters, running vertically from the roof to the ground. Its primary function is to channel water off of your roof and away from your property.

20. Gutter

Attached to the eaves of your roof, the gutter is a long basin that catches rain and melted snow. Made out of galvanized metal, plastic, or vinyl, gutters are essential for directing water away from your home.

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Jessica Stone
Jessica Stone

Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.

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