What Are the Parts of a Roof? - Roofing Parts

What Are the Parts of a Roof?

Most people understand that roofs are important and that they’re necessary to have one on your house. Roofs offer protection from the weather and comprise the home’s construction. What most people don’t know about roofs is how complex they are. Rather than just a thin layer of roofing material, they’re composed of an intricate structure that allows for premium durability and strength. When you have a roof installed, it’s crucial that all parts are correctly placed. Any discrepancies with an installation can cause major issues and greatly impact the lifespan of your roof. Understanding the different parts of your roof can help you ensure that your roof is operating properly. 

parts of a roof

Roof Structure 

The roof structure is extremely important to the integrity of the roof, given that it creates the baseline for other parts. When the installation is being performed, careful attention to detail should be given to the structural parts, because if issues are present here, they will spiral outwards to other roofing parts.


These structural beams run from the roof’s peak to the edge and support the roof deck. If not installed properly, it can be detrimental to your roof. When weak, rafters can cause the roof to sag or dip in sections, which can lead the roof to collapse. 


Purlins are horizontal beams that lay on top of the rafters. They provide additional support and tie the rafters together. They are essential in providing durability and strength to the roofing structure, especially for roofs exposed to severe weather. 


The pitch is the slope of the roof or angle of inclination. The pitch is determined by the framing: the rafters and purlins.

Roof Covering

The roof’s covering contributes to the first line of defense against the elements. These roofing features play an important role in insulating the roof against moisture and other water leaks. If not installed correctly, water can seep into the attic and ceilings, wreaking internal damage. 


The underlayment is a water-resistant material installed onto the roof’s surface. Typically, the material is an asphalt-saturated felt, which works to be a secondary water barrier in case water sneaks beneath the shingles and decking. 


The decking, usually composed of ½ inch plywood, lies on top of the underlayment. It can be composed of different materials, but its purpose is to reinforce the roof’s structure. It also provides a nail bed for the shingles and insulates against moisture.


Shingles are the visible elements that make up the surface of your roof. Most shingles use asphalt, as it’s the most affordable, versatile, and widely available material. They can also be customized, so you can choose the color, finish, and size.


The flashing is the most important roofing material in preventing water damage. In susceptible areas of your roof, such as the sides of a chimney, water can leak into the structure. It’s here that flashing will be installed at any surface intersecting with the roof, such as pipes, chimneys, skylights, vents, and valleys. Flashing is water and mold-resistant, so it acts as a sealant to keep the internal roofing structure safe.

Roof’s Edge

The roof’s edge parts work in defense of water and debris. 

Drip Edge

Drip edge is a moulding that works to reduce water infiltration. It covers the edge of the roof and will attach to the decking. While not all roofers install drip edge, we highly recommend it, as it’s important in adding another layer of insulation. 


The fascia lies on the exterior part of the roof, acting as a band that follows the roof’s edge. It attaches to the gutters and helps your roof appear finished. It also supports the shingles and works to keep moisture out and allow proper ventilation. 

Gutters and Downspouts

Gutters connect to downspouts, which move water away from the roof. It’s important that you have your gutters cleaned every few months so that water and debris can move swiftly through the gutters and downspouts. 

Contact Us For Help With Your Roof!

Next time you need a roof repair or new roof installation, Perimeter Roofing Columbus is your team! We install all parts of the roof with extreme attention to detail. Now that you’re familiar with the parts of a roof, examine yours! If you want a free roofing inspection, we’re happy to provide one. Schedule your free inspection online today! 

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