What Does A Complete Roofing System Consist Of?

May 27, 2023 | Roofing

A roof is more than just a set of shingles – it’s a system of components working together to protect your home. From structure to insulation, ventilation, and drainage, each component plays a crucial role. Here’s a closer look at what a complete roofing system consists of. 

What Does a Roof System Include?

Roof systems contain a variety of layers, such as the roof deck, ice and water shield, underlayment, flashing, roofing materials, vents, and more. These elements are important in making sure the roof functions properly, is durable, and lasts as long as possible. 

Roof Deck

The roof deck is the foundation of the complete roof system. It’s typically made of plywood and is the base layer that other roofing components are attached to. The roof deck must be able to properly support those components, as well as roofing contractors working on the roof, snow, ice, fallen branches, and other items that may land on the roof.

Ice and Water Shield

The ice and water shield is a waterproof layer that offers protection to the roof deck against – you guessed it – ice and water. Your roof is constantly exposed to a variety of weather conditions, and you don’t want rainwater, snow, or ice seeping into your home and causing water damage. The ice and water shield serves as a leak barrier and is commonly installed at the edge of the roof and near chimneys, eaves, vents, skylights, and gutters.   


Another protective layer, the underlayment is a breathable and water-resistant barrier that extends the life of the roof deck. It can also be fire-rated, meaning it will help minimize the spread of fire if one occurs. 

Underlayment Materials

Roofing underlayment is commonly made from either asphalt-saturated felt, rubberized asphalt, or a non-bitumen synthetic material made from polypropylene or polyethylene. 


Flashing is metal that is attached to the roof in places where two surfaces meet to direct rainwater away from those areas. Flashing is typically installed where the roof and chimney meets, at eaves (edges of the roof that extend past the home’s exterior walls), and at valleys (where two sloping planes of the roof meet). Flashing prevents water from seeping through the roof and damaging it. 

Types of Flashing 

There are four types of flashing used in the roofing system: drip edge, step flashing, cap flashing, and valley flashing. Drip edge is installed at the roof’s outer edges. Step flashing is applied directly to the roof. Cap flashing is added to a wall or chimney. Valley flashing is applied in valleys of the roof. 

Roofing Material

Roofing materials provide additional protection to the roof. Popular roofing materials include shingles (often asphalt, wood, or composite), tiles (often slate or clay), and metal. Ridge capping is also added to further protect the roof. 


Shingles are flat pieces of roofing material that overlap to give the roof protection from the elements. They also contribute to the overall appearance and style of your house. Roof shingles are available in a variety of colors, textures, and materials, including asphalt, wood, and composite materials. We typically recommend asphalt shingles for their durability, affordability, and lifespan. 


Tiles are another option for the outermost layer of your roof. Roofing tiles are often made from either clay or slate. Clay tiles feature a reddish-orange color and can be glazed or unglazed. This material is a popular choice in areas with hotter climates or salty air. Slate tiles are made from slate that has been mined and cut into squares. They must be installed one at a time rather than in groups or panels, making them an expensive option. Clay and slate tiles are both durable roofing materials.  


Metal roofs are often installed in the form of a standing seam metal system, which features interlocking metal panels. The panels can expand and contract when the metal gets hotter and colder as the temperature changes. Other options for metal roofing include corrugated metal (which has a wavy appearance), metal shingles, or metal shakes. Metal roofs are typically made from either aluminum, stainless steel, or copper.

Ridge Capping

Ridge capping serves as a protective covering for the point where two sides of a pitched roof intersect. It’s typically made from asphalt or metal and prevents water from damaging the roof. It also provides a polished and complete appearance to the overall roof structure.


Too much hot air in your attic can cause wear and tear on the roofing materials and lead to mold and mildew growth. Ventilation prevents this buildup of heat. Proper ventilation extends the lifespan of your roof, keeps the inside of your home a comfortable temperature, and lowers energy costs. Ventilation can be mechanical (which involves a power source) or natural (which features exhaust vents). Some homes also have air intake vents. 

Exhaust Vents

Exhaust vents are typically installed towards the top of the roof line, allowing hot air that rises to the attic to leave your home. There are many types of exhaust vents, including ridge vents, box vents, hard-wired powered attic vents, solar powered attic vents, roof turbines, and cupola vents.

Intake Vents

Intake vents allow fresh, cooler air to enter the home and push existing, hotter air out of the attic through the exhaust vents. There are a variety of intake vents to choose from, including soffit vents, gable vents, over fascia vents, and drip edge vents.

Additional Roofing Elements

Your roofing system may have additional elements to the ones we’ve already mentioned, such as fascia and soffits, gutters and downspouts, skylights, and chimneys. 

Fascia and Soffits

A fascia is a vertical board that’s installed along the edge of the roof, typically where the roof meets the outer walls of the home. The fascia prevents water damage to the underlying roof structure by stopping moisture from entering the roof and redirecting it to the gutters.

Soffits are the horizontal boards or panels located on the underside of the roof’s overhang or eaves. They often have vents that allow fresh air to enter the attic space, promoting airflow and reducing the risk of moisture buildup. Soffits can also be fitted with insulation material to enhance energy efficiency by reducing heat transfer between the attic and the living spaces below.

Gutters and Downspouts

Proper drainage helps prevent water damage to the roof and other areas of the home. Gutters are troughs or channels that collect rainwater running off the roof and direct it away from your home. Gutter covers block out large debris while still allowing water to enter the gutter. Downspouts are vertical pipes that carry water from the gutter to the ground or drainage system.


Skylights are windows installed on the roof, allowing natural light to enter the interior spaces below. Well-designed skylights can help reduce reliance on artificial lighting and potentially lower energy costs. Some skylights can be opened or equipped with vents to provide fresh air circulation and improve indoor air quality. 


If you have a chimney as part of your roofing system, you likely also have chimney flashing and a cap and crown. Chimney flashing is metal flashing around the base of the chimney that prevents water from seeping in. A chimney cap and crown covers the chimney top to prevent debris and water from entering your home. 

Benefits of Residential Roof Repair and Replacement

The roof offers your home protection from the elements, so it’s important to keep it in top-notch condition. Having a contractor inspect and repair your residential roof on a regular basis extends the life of your roof and prevents problems like leaks or storm damage from getting worse. When necessary, roof replacement ensures your home will be properly protected.

About Whitt Roofing & Restoration 

A family owned and operated business, Whitt Roofing & Restoration provides roofing services to the Columbus, Ohio community. We offer roof inspection, roof installation and roof replacement, roof repair, gutter service, siding installation, and more. Our highly trained team will design a personalized plan based on your specific roofing needs, and each contractor provides exceptional service. Contact us to learn more about our roofing and home improvement services. 

Contact Us 

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