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29 Different Parts of a Roof Structure

Everyone knows that fixing or replacing a roof is a complicated endeavor that can involve detailed knowledge about the parts of a roof structure. It’s not exactly a common do-it-yourself task. But learning about the different parts of a roof can be helpful in breaking down this seemingly large task into smaller parts that can make it easier to understand. 

Roofing can generally be broken down into a few different elements: structural, protective and decorative. Structural parts of the roof, like rafters, beams and trusses serve to make a roof strong and durable, able to stand up to harsh weather conditions like snow, rain and even high winds. Protective elements like flashing and underlayment help to keep moisture out of your roofing materials, which prevents leaks in your home and buildup of mold or mildew. Finally, decorative elements like dormers, skylight and the roofing material itself bring a certain aesthetic to a home’s exterior. 

Here, we’ll take a look at 29 different parts of a roof structure. Having this knowledge and equipped with a fast a free roofing estimate from our AI-powered roof replacement cost calculator, we’ll then dive into the signs that indicate it might be time to replace or repair your roof. In most cases, if that becomes necessary, you may want to find a roofer in your area. 

What Are the Different Parts of a Roof?

Here are 29 terms you may need to know if you think it might be time to repair or replace your roof. Becoming familiar with these common roofing terms is a great start if you want to communicate effectively with a roofing professional. You’ll have a better understanding of how your roof fits together and functions as a whole once you’ve browsed this list of the different parts of a roof structure. 


The part of the roof that meets the wall of the home. This creates a seam, which can potentially allow for water to seep in. Therefore, flashing or another protective material should be used on any abutments. 


The interior space between the roof and ceiling of the highest floor of your home. They are important pieces to maintaining the insulation of your home.


Wooden boards, which can run either vertical or horizontal, that serve to elevate the outermost roofing materials (most often used with tiles) from the roof deck. This can help promote air flow.  


A vertical structure extending from the roof that provides ventilation for a fireplace. Flashing or another protective material should always surround a chimney to prevent water leakage. 

Collar Beam

A wooden beam that sits horizontally between two roof rafters and provides additional support. These can sometimes be decorative or required.


Long, flat boards that serve as the framing of a roof. Decking can be either in planks or sheets: planks resemble hardwood flooring in homes, while sheets (which are more commonly used today) are long, flat pieces of plywood.


This is the term given to a window that extends from a sloped roof. Rooms with dormers often have slanted ceilings, unless the dormer is “ornamental,” which means it sits on the roof but does not extend into the home’s interior construction.


The downspout serves to remove water from the roof. It connects to the roof’s gutter, and allows water to flow down from the gutter onto the ground. 

Drip Edge

A thin metal piece installed at the edge of a roof to help direct water away from the roof and into the gutter. 


The edge of the roof that extends beyond the outermost wall of a structure or home. 


A fascia board runs along the outermost edge of a roof, serving both decorative and functional purposes. The fascia can help keep moisture away from the roof and the home’s interior, and also provides a finished look to the roof’s edge. 


What is roof flashing? Made of thin material, like galvanized steel, flashing is used to surround roof structures outside of the roof plane, like a chimney, vent or skylight. It helps keep moisture from seeping into the seams created by these structures. 

Flat Roof

A roof with a pitch of less than 10 degrees that’s best suited to warm, dry climates without temperature extremes or lots of rain.


What is a gable roof? The triangular piece of a home’s exterior that connects to the end of a pitched roof. The gable is typically constructed in the same material and color as the rest of the home’s exterior, for a seamless look. 

Gable End

A term used to describe an exterior wall of a home with a gabled roof. The gable end is characterized by a straight side that follows the line of the roof, sitting below any overhang, and extending up to the gable itself.


What is a hip roof? A roof in which all four sides extend downward from a peak. The hip is the external angle where the four sloping sides meet. Often found on churches, it’s a great option for wet climates, since moisture easily rolls down the sloping sides. 

Hipped Edge

The edge of a hip roof.

Ice and Water Shield

A waterproof shield that lays on top of the roof decking to prevent any ice and water that seeps into the roofing material from damaging the decking.


Horizontally oriented wooden beams that support the structural portion of a roof.


Wooden beams used to frame the roof which connect to exterior walls. 

Rain Gutters

Made of metal, PVC or plastic, rain gutters are long pipes attached to the edge of a roof that serve to direct rainwater from the roof to the ground.


A long, thin piece of roofing material that covers the section where two roof planes meet. It serves to prevent water from leaking into the seam. 

Roof Covering/ Material

The outermost layer of a roof. Common roof covering materials include asphalt shingles, clay tiles, galvanized metal, and slate.


A skylight is essentially a window cut out of the roof. It differs from a dormer in that it faces the sky, while a dormer is cut into the slope of the roof and faces outward like other windows of the home. 


The underside of a roof overhang.


Wooden or metal beams that provide support to a roofing structure. They differ from rafters in that trusses are prefabricated, computer-generated structures that have to be delivered to a work site already constructed.


Thin material that’s rolled onto the roof decking to add an additional layer of moisture protection. The two main types of underlayment are felt and synthetic.


A roof valley is when two parts of a roof meet at a slope to form an interior angle on the roof. Roof valleys serve to help remove moisture from the roof. 


A roof vent is installed on the roof to allow for proper air circulation in the attic of a home, and to prevent condensation from building up in the roofing material.

What Are the Signs You Need to Replace Your Roof?

While it’s helpful to know the different parts of a roof structure, as a homeowner you also need to be informed about when it’s time to repair or replace a roof. As a major financial investment, a roof will last many years, but repairs may be necessary along the way. This can help extend the life of your roof, and prevent early replacement. In addition, being able to spot early signs of disrepair can help you budget properly, and hopefully save some money to put  toward the expense of replacing your roof. 

Age Of Your Roof

Especially if your roof has shingles, you’ll hit the replacement point once it’s around 20 years old. Other materials last significantly longer, like metal (40 to 70 years), slate (50 to 200 years) and clay tile (50 to 100 years). You’re much more likely to face repairs rather than replacements with these long-lasting roofing materials. 

Curled, Cracked or Damaged Shingles 

Each year, take a moment to visually inspect your roof. Damaged shingles should be replaced as soon as possible to prevent moisture or wildlife from getting into the cracks of your roof. But a large number of peeling, cracked, curled, damaged or missing shingles likely indicates that it’s time to replace your roof. 

Moss Growth

While moss isn’t harmful to your roof on its own, its presence indicates there might be moisture in or on your roof. And over time, this moisture can cause roof damage that leads to leaks. 

Sagging Roof 

A sagging roof is a red flag that your entire roof might need to be replaced due to extensive water or structural damage.

Leaks Inside the Home 

If you’re noticing water stains or leaks inside your home on the upper levels, it’s time to inspect your roof. Start with the attic, if you have one. Leaks should be repaired immediately, and it might be a good idea to contact a roofing professional to discuss whether the roof needs to be replaced. 

What to Do When Part of Your Roof Fails

It’s normal to feel a sense of dread when you’re faced with a roofing issue, especially if it seems like a major one. But remember – roofs are meant to last many years. So unless your roof is very old or has sustained major damage, you may be able to have it repaired. 

Facing replacement? Start by finding an accurate roofing calculator, like the AI-powered one offered by Instant Roofer. This is a great place to start, since you can get a rough estimate of the costs you’ll face right from the comfort of your home. Then, you can start looking for a qualified roofing professional. 

Connect to Vetted Professionals in Your Area Today 

When faced with damage or destruction of any of the different parts of a roof structure, it’s best to get the advice of a qualified roofing professional before trying to diagnose the issue on your own. Below are just a few of the benefits of consulting with a professional for any roofing matters: 

  1. Expertise

While some roofing issues are small and simple, like attaching a gutter, others require in-depth knowledge in order to maintain the structural integrity of your home. A qualified roofing professional will know the difference, and can advise on how to proceed. 

  1. Time

DIY jobs sound attractive, but it’s important to realize that life often gets in the way. You could be called away to handle other matters, or a job could take longer than anticipated, leaving your roof in a half-finished state. A professional will outline the scope of the work for you, leaving you with no question as to how long it will take. 

  1. Guarantee

You might pay more to have a roofing professional handle your roof issue. But the work should be guaranteed (be sure to check this upfront, before signing on the dotted line), which means you can rest assured that the work done will be of good quality. 

Fact Checked by Christin Perry 5/17/2024