Roofing 101 Parts Of A Roof Explained

Roofing 101: Parts Of A Roof Explained


March 4, 2022

Whether you’re a DIY roofer or you’re a new homeowner, you need to know important things about your roof so that you can maintain it properly.

As you know, correct roof maintenance can increase the lifespan of your roofing materials.

What’s the most important part of a roof?

It’s said that the eaves are the most important part of your roof, because they prevent water from affecting the walls of the home.

But there are many parts of the roof that you should know about. Let’s explore them. 

20 Important Parts Of A Roof And Their Functions 


Roofing 101 Parts Of A Roof Explained

Roof shingles are roof coverings that make use of individual overlapping elements. These are flat, rectangular shapes that are placed from the bottom edge of the roof all the way up, and they overlap.

Roof shingles come in a variety of materials, such as asphalt, concrete, and clay. In the U.S., asphalt roof shingles are the most popular because they are lightweight, easy to install, and don’t cost a lot of money.


Roofing 101 Parts Of A Roof Explained

The roof eaves are the areas where a roof extends past the wall of the home or building. The eaves are important because of how they prevent water damage as well as animals from nesting in the roof.

There are three main types of eaves: 

  • Open eaves. This is when an overhang has an exposed underside as well as visible rafters. 
  • Closed eaves. This is an overhang that has a soffit which finishes the underside of the eaves. 
  • Box eaves. These eaves are made up of an overhang that is enclosed with a soffit and ornamental molding. This prevents the rafters from being visible.

Ridge Board 

Roofing 101 Parts Of A Roof Explained

A ridge board is used to join the ends of opposing roof rafters. When a roof is constructed, a ridge board will support the highest end of the rafters, not just vertically but laterally. It’s basically an aid that helps you to correctly place and connect opposing rafters and it helps to frame the roof. 

You’re most likely to find a ridge board in a roof structure that has roof slopes which are between 3/12 and 12/12. They are commonly found in gable, hip, gambrel, saltbox, as well as mixed combination roof styles. 

Solid Decking

Roofing 101 Parts Of A Roof Explained

Solid decking, known as a solidly sheathed deck, basically means that the roof contains a solid wood surface on which asphalt or other types of roofing materials are fastened. Therefore, the decking of your roof needs to be strong and durable. 


window that gets installed on the roof.

A skylight is basically like a window that gets installed on the roof. It has an insulating piece of glazing that’s inside an aluminum frame. You can choose between operable skylights, which can be opened to let in air, and fixed skylights, which don’t open and their airtight nature makes them more energy efficient.


Roofing 101 Parts Of A Roof Explained

A chimney is essentially a vertical tube that removes smoke from an indoor fire so that it can be pushed through the roof. You can see part of the chimney as it protrudes from the roof, and it’s usually made of bricks. Inside the home, a chimney will be positioned above a fireplace to quickly and efficiently draw smoke fumes away from your living space.

Chimney Flashing

Roofing 101 Parts Of A Roof Explained

This is roof flashing that is used to produce a waterproof seal, protecting your chimney and roof from moisture and water damage. An example is step flashing, which is found between the roof and chimney. It’s an L-shaped piece of metal that gets placed underneath the roof shingles as well as along the brick of the masonry chimney.


Roofing 101 Parts Of A Roof Explained

Fascia is a finishing edge that is used to connect your roofing to the rafters, gutter attachments, or trusses. It’s made out of wooden board or sheet metal. Fascias are necessary in your roof system design because they cap the edges of rafters and hold your gutters in place, both of which maintain the correct water drainage of the roof. 


Roofing 101 Parts Of A Roof Explained

A gutter is a long and hollow device that gets attached to your roof edges. It collects rainwater and directs it away from the roof structure, thereby preventing water damage. A gutter gets installed with a downspout.

Having a gutter system installed on your roof is important because it prevents water runoff from accumulating around and inside your house. 


Roofing 101 Parts Of A Roof Explained

A downspout is the bottom piece of a gutter that directs water from the roof to the ground. Downspouts are pipe-like, vertical devices that are connected to gutters. When installing downspouts, you have to ensure you have one every 30 to 40 feet.

This generally means that you will install spouts at either end of a gutter section. 

Collar Beam

Collar Beam

A collar beam is very common in construction because it’s a horizontal structure that’s placed between two rafters. This beam is structural, but it can also be used to frame a ceiling. Note that sometimes a collar beam is called a collar tie.



A rafter is a structural roofing component that runs from the ridge of the roof to the wall plate of the external wall. Rafters get placed side by side in a series, so that they essentially produce a foundation that supports your roof deck and coverings.

They are usually made out of timber or steel that can either be hidden within the structure of the roof or left exposed for decorative purposes. 

Felt Underlayment

Felt Underlayment

This is one of the oldest types of roof underlayment and it’s made by saturating fiberglass or paper mat with asphalt. This roofing felt is used to provide a layer of protection between the roofing shingles and roof deck. Roofing felt has many other benefits, such as that it provides an even surface on which your roofing shingles can lie flat.


Roofing 101 Parts Of A Roof Explained

The rake of a roof is the exposed part of the sides of a gable roof. It extends from the eave to the ridge of the sloped sides, and it covers the top edge of the roof.

The gable roof design is one of the oldest, and it has two roof sections that slope in opposite directions from the peak. This enables greater elimination of moisture from the roof. 

Vent Pipe Flashing

Roofing 101 Parts Of A Roof Explained

This type of flashing is cylindrical in design with a flanged, large base so that you can lap it into your roof shingles. Installing this flashing on an existing roof is a good way to help it stay in good condition without hurting your wallet. 

Valley Flashing

Roofing 101 Parts Of A Roof Explained

This type of flashing is flashing that protects the roof where two slopes join to form a valley. This pushes water run-off down the roof and into the gutters so that it can be properly removed instead of lingering around and causing water damage. 

Valley Underlayment 

Roofing 101 Parts Of A Roof Explained

To protect the roof valleys, underlayment is often used. This usually takes the form of asphalt paper roofing felt. This has been considered the standing for decades but it’s not as watertight as other materials, such as peel-and-stick underlayment.

This is made out of high-density polyethylene or polyester that’s coated in modified bitumen, a combination of asphalt and rubberized polymers. 

Splash Block

Roofing 101 Parts Of A Roof Explained

A splash block is a rectangular piece of concrete or plastic that gets positioned beneath the end of the gutter downspout. This is used to direct water away from your home. It also works well to prevent muddy water from getting splashed onto the ground and tarnishing your walls. 

Although they are classically rectangular in shape, a splash block can be purchased in various shapes and designs, such as by mimicking the appearance of leaves or animals, which is a good choice if you want a decorative one for your home.


Roofing 101 Parts Of A Roof Explained

A lookout is a wooden joist that extends from the exterior wall of the home and supports the roof sheathing. It’s a short horizontal rafter that frames the rafters which overhang a wall on the edge of a roof, but can also be used to extend the gable roof edge. 

You’ll find that most of these products are made of lumber. They are usually enclosed at the side of the house and have a covering on their base called a soffit.

Spaced Sheathing 

Spaced Sheathing

This is something you’ll find in older homes. Otherwise known as skip decking, spaced sheathing is decking that has wooden boards running horizontally to the rafters with about four to six inches between them.

You’ll find this in homes that were originally built with wood or cedar shakes. While it works with wood, it’s not strong enough to support asphalt composite shingle roofs. 

How Is A Roof Constructed? 

Whether you want to build your own roof as a DIY project or you’re just curious about how a roof gets built, read on to learn more about the process and how the parts of a roof that we featured earlier come together. 

  1. Start by installing your drip edge. This gives the roof a complete finish and it prevents shingles from becoming damaged during the roof installation. Your edge needs to be secured to the eaves before you can install the underlayment.
  2. Install the underlayment. This prevents harsh elements such as rain from penetrating your roof and entering the home. Underlayment is installed so that it’s straight and flat. Some types of underlayment are self-sticking but others require nails to keep them securely fastened.
  3. Install felt paper or tar paper. Covering the roof with this paper removes moisture that can accumulate underneath the roof’s shingles. This paper gets rolled out into short sheets and then staples are used to fasten it to the roof deck for increased coverage.
  4. Start applying the roof shingles. These shingles have to be overlapped. The starter shingles are designed to make up the first row that’s flat and only half as wide as the regular shingles. They help to form a barrier that prevents water from getting between the seams of the first row of shingles.
  5. Continue installing your shingles, followed by the flashing. This will ensure that you have a waterproof seal around structures of your roof, such as the chimney and windows, to prevent water from seeping in.
  6. Cap your ridge. The ridge is the name for the shingles at the peak of the roof. These shingles need to be secured with longer nails.
  7. Seal all the exposed nails. You should use a roofing sealant for this purpose to ensure that no cracks or gaps can form around the nails. This will prevent them from wear and tear, as well as water damage. 

Related Questions 

How long does it take to replace a roof?

A roof can usually be replaced within a few days, but this does depend on the type of roofing material. For more information, read, “How Long Does It Take To Replace A Roof?

What type of roof has the longest lifespan?

There are many roofing materials that can last for several decades, such as metal, clay, slate, concrete, and tile. 


If you’re going to install a roof on your new home, it helps to know how a roof will be built and what the different parts of the roof do.

This will ensure you get a high-quality roof installation. In this article, we’ve featured some of the most essential roofing components and how roofs get constructed.



James Weldon is a professional roofing contractor with many years of experience on the job. He does not only handle large projects and provide excellent services for his company’s many clients; James Weldon also dedicates his spare time to teaching others useful tricks of the trade. Using BuildCampus as an avenue to reach many roofers and aspiring roofing contractors, James Weldon continues to provide high-quality educational posts and buying recommendations for anyone who visits the website.