What Are The Different Parts Of A Roof?

Posted on August 8, 2022

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What Are The Different Parts Of A Roof?

Learning about the parts of a roof is critical for every homeowner. Sloped roofs have a complicated structure that plays a significant role in keeping your home safe, comfortable, energy-efficient, and beautiful for years to come.

You must understand every roof component closely if you are:

  • Planning to buy a new house
  • Repairing or remodeling your current one
  • Selling or renting your house
  • Replacing a damaged roof.

This is a detailed article on primary roofing layers and crucial safety components. While some people may find a few roofing parts optional, knowing everything about each part of the roof is in your best interest.

#1 Roof Structure

When you want to understand the different parts of a roof, this is the first one you should become familiar with. The roof structure is the load-carrying portion of your home’s framing system, called roof decking or sheathing. The primary function of a roof structure is to support the weight of the building’s exterior walls and support the entire roofing system. This whole structure is formed of plywood or OSB sheets. Different parts of this framing include rafters, trusses, joists, and purlins.

Roof structure
Roof Structure


Rafters run horizontally from the top of the roof down to the external wall. Rafter boards are installed parallel to each other, giving a base to support all the roof components. You may also know them as wooden beams or trusses. Trusses have a more intricate triangular structure and they provide better support for the roofing materials.

You can read in detail about Rafters and Trusses in our blog.


The ridge is your roof’s peak or the highest point of a roof where two roof planes meet. The roof’s ridge runs horizontally, supporting the top ends of all the rafter boards.


Joists are the horizontal boards that support the attic floor and ceiling. These boards also aid the home’s insulation, plumbing pipes, electrical wiring, and more.


Purlin is a horizontal support beam that runs lengthwise between the rafters and joists. It holds up the rafters and prevents the roof from sagging.

A roof structure needs to be carefully measured. The boards need proper gaps between them and they must be thick enough to support your roof. Choosing an experienced roofing contractor is critical when you are installing a new roof on your home. Professional roofing contractors will also install essential roof safety components like underlayment- the waterproofing sheet that covers your roof sheathing.

#2 Underlayment

Underlayments are one of the most essential parts of a roof that some homeowners may overlook. An underlay plays a significant role in determining your roof’s lifespan. It is a water and fire-proofing layer of a sheet that covers your roof’s wooden structure. It contains flexible and durable materials like rubber, fiber, felt, and foam to protect your home from leaks and other external damage. Roofing Underlayment provides space and support for installing the last roofing layer or the roof covering. If your house faces harsh weather conditions such as winter storms, heavy rainfall, hail, high winds, etc., underlayments will keep it safe if the roof covering breaks or pulls off.

#3 Roof Covering

The roof covering is the top layer of a pitched roof. It’s the biggest and most visible part of your roof, and it is the first line of protection against the elements. The type of roof covering you choose can determine how long your roof lasts and how nice it looks. It can also impact the energy consumption in your home. You will generally see three types of roof coverings that people choose according to the local climate, their budget, and the homeowner’s aesthetic taste.

Asphalt Shingles

Asphalt shingles are blocks or plates made of asphalt, fiberglass, and ceramic granules. Most US homes use asphalt shingles to cover their roofs because they are inexpensive, sturdy, and beautiful! Asphalt shingles are fire and water-resistant, and they come in appealing patterns like architectural, traditional 3-tab shingles, and luxurious looks too!

Wood Shakes

Wood shakes (usually cedar shakes) fall under luxury roof coverings due to their longevity and attractive, rustic looks! Wood shakes are resistant to hail damage, high winds, and, surprisingly, fire! You can choose from many beautiful shades and textures if you decide to install a wood shake roof!

Metal Roofs

Metal roofs are great for extremely hot or cold climates, and they are efficient in humid areas that experience heavy rainfall. Many people select metal roofs for their homes because they are incredibly durable, aesthetically pleasing, and require little maintenance. The most popular types of metal roofs are aluminum, galvanized steel, and copper as they don’t rust and can last for decades!

You can install more components like valleys, chimneys, roof vents, and skylights on the roof covering. Using flashing, you can nail or seal different components to the roof covering.

You can check our blog on “Different Metal Roof Styles” to see which fits your home style the best.

#4 Ridge Caps

Ridge caps are special, pre-curved sheets or blocks that cover your ridge (the roof’s peak). They are especially common in shingle, metal, and tile roofing systems, but they can also provide added protection to other types of roofs. Ride caps are thicker than the rest of the roof covering material so they can prevent wind and water damage. Ridge caps are protective materials that exhibit a mindful approach to the roofing work, and they help if you even need to file an insurance claim for roof damage. They are critical for Georgia homes, where seasonal storms hit the state with winds blowing from 39 to over 100mph.

#5 Flashing

You can find flashing around multiple parts of a roof. Roof flashing is a piece of synthetic material that prevents water from seeping through the joints between different roofing materials, such as shingles and a chimney. Aluminum, galvanized steel, and copper are some of the most common materials used for flashing.

#6 Valleys

A valley is a long, narrow slope where two sides of a roof meet. Before installing shingles, a flashing material covers the valleys, protecting the wooden sheathing underneath. Valleys also prevent ice dams by diverting rainwater and melting snow away from your home’s foundation.

#7 Drip edge

The drip edge is also a type of long metal flashing covering the edge of your roof. This strip prevents rainwater from reaching the lower roof components installed below the roofline or eaves. Without the drip edges, water can end up under the shakes or shingles, and it can cause damage to your roofing system, siding, walls, and more. Though initially, some homes did not have this roofing component, drip edges are now required by most US building codes, including Georgia’s.

#8 Eaves

Eaves are parts of a roof that hang past the external wall of the house. They are both decorative and protective elements in a home. When the eaves are long enough, you will have space underneath to install soffits or shelter a porch. They also protect your home’s siding and foundation from water, hail, and wind damage. Elaborate, stylish eaves enhance your home’s value and curb appeal dramatically!


Soffit is a material that covers the underside of the eave, and it protects the rafters from water damage. It is typically made of wooden, vinyl, or metal boards. You can choose closed or perforated soffit boards according to your home’s ventilation plan. With diverse colors and stylish patterns available, soffits can give your home a finishing touch that is elegant and charming.

Fascia Boards

Fascia is the board that connects soffits to the roofline, covering the top of the rafters. It’s a fine trim that protects the gable and rafter’s ends. Gable is the triangular front portion of your sloped roof. Experienced and creative roofing professionals can offer attractive designs for your fascia boards, and they will help you choose the best materials for your budget.

Buyers and tenants will favor your home, and it will relish a higher value in the market if it has:

  • Correctly installed architectural shingles
  • Clean, painted eaves
  • Proper ventilation system

When you learn about the parts of a roof, it is important to understand the roof ventilation system properly. It may not contain roofing components, but the ventilation system is attached and it affects the roof and attic in many ways.

#9 Roof Ventilation System

Adequate roof ventilation keeps your home comfortable, and it can even keep your energy bills lower. You may have seen round, rotating structures on some roofs; these are the roof vents. The roof ventilation system consists of a few intake and exhaust roof vents that exchange hot, moist air of the attic with cooler, drier air outside. You can maintain your home’s desired temperature and humidity level by controlling the ventilation. It can also protect your home’s interior and roof structure from leaks and moisture damage.

Exhaust vents

Generally, exhaust vents are also known as attic fans. That’s because exhaust vents remove hot air and moisture from the attic. This is essential to prevent ice dams, mold, algae, and rot. The best place to install exhaust fans is at or near the ridge.

Intake vents

Intake vents work well with exhaust vents. They allow the outside air to flow into the attic space, and they can prevent moisture damage. They are crucial to maintaining the structural integrity of your roof. You can install intake vents near the lowest part of the roof or below the roofline as vented soffits.

Ventilation systems function with the highest efficiency when your attic is well-insulated. Insulation is a material to seal the unauthorized entry and exit of air and elements from the attic and roof.

#10 Attic Insulation

Insulation is a layer of material that fills the gaps in the attic walls, ceiling, floor, door, and unconditioned spaces. It prevents unwanted airflow from the attic, and you can install it in the form of fiberglass batts and rolls, spray foam, etc. Insulation can also help reduce noise from rain and hail.

#11 Roof Drainage System

Among the most important parts of a roof, the drainage system forms the outermost component, extending down to the porch, lawn, and yard. It contains several gutters and downspouts that prevent severe water damage to your home. Together, they divert rainwater away from the roof, landscaping, and home’s foundation.

Rain Gutters

The gutter is the piece that channels water from the roof to the downspout, which then carries it away from your home. Rain Gutters often come in aluminum or galvanized steel, and you can paint them to suit your needs. They’re available in various styles, including half-round shape, K-style, Victorian Ogee, or more sturdy ones like fascia gutters.


Downspouts are long, vertical pipes attached to the gutter. They carry the rainwater down the roof, along the exterior walls of the house. The size of your home will specify how many gutters and downspouts you need, and how long they should be.

Many more safety components are designed for residential roofs, such as gutter guards, downspout screens, splash guards, green roofing components, roof louvers, and more.

At Division Kangaroof, we are passionate about the roofing industry. Our expert team is always excited to discuss roofs, and we will answer all your questions without needing anything in exchange!

Want To Learn More About Roofs From The Experts?

We understand how important it is to plan, research and choose the best roofing materials for your home. Division Kangaroof is a family-owned business that has been offering roof replacement services in Habersham County for over 15 years! Our previous clients trust and prefer our team for any roofing service.

We hope you find our article helpful and that you now have a good idea about all the main parts of a roof. We would be glad to guide you if you want to know more about residential roofs, and which roofing components are essential for your home. Our team takes pride in the work that we do, and we know it’s our duty to help the community.

Contact us at (706)-778-3516 for a free consultation, roof inspection, and estimate. We will hop to your place in no time!

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