2020 Roofing Guide: What Are The Parts Of A Roof?


As a business owner, what’s the value of knowing the parts of a roof? Isn’t it the job of roofing contractors to know these things?

The truth is that yes, you should fully understand the components of your commercial roof.

Knowing your roofing from the inside out enables you to take care of it completely. And if you do, it reciprocates with excellent performance and reliability. In the end, you’ll get the value for your money and enjoy a sturdy roof to support your growing business.

Read Also: What Are The Best Flat Roofing Options This 2020?

If you are a hands-on Ohio-based entrepreneur and would like to take commercial roofing seriously, we encourage you to read until the end of this post. We’ve shared important tips on how to keep your roofing investments in good shape.

Without further ado, let’s begin.

3 Basic Parts of a Roof

Most commercial roofing systems are composed of only three main parts. This is significantly lower in quantity as compared to pitched residential roofs. Why is this so?

Commercial roofing is pretty straightforward. Hence, we have what we call low-slope or flat roofing. It does have slight pitches but these aren’t visible from afar.

Flat roofing prioritizes functionality rather than the overall appearance. This is the main reason why buildings, industrial facilities, and other commercial establishments have low-slope roofs.

Continue reading below to find belongs to the three basic parts of a roof:

Weatherproofing Layer

To prevent water and moisture from penetrating your property, you need a reliable weatherproofing layer.

This is the element that keeps your property dry and protected all year round regardless of the weather. May it be sunny or rainy, you are safe.

Failure to install a high-quality weatherproofing layer can lead to serious water damages. This compromises the integrity of your property and could be costly to fix.


As the name implies, it’s the part responsible for increasing the roof’s strength and durability. It supports the roofing membranes to make sure that they become puncture resistant and tough enough against external threats.

Like with any other roofing systems, you need reinforcement so that it can stand better in shifting weather conditions and are not easily affected by the daily wear and tear.


We call the third element ‘surfacing’ because its main role is to protect the two other parts of a roof from direct sunlight and other natural elements like high winds, rainwater, snow, and many more.

Thanks to technology, modern surfacing can provide effective solutions against external threats that include fire, hail, and heavy foot traffic. There are surfacing products that also increase the roof’s capability to reflect heat coming from the sun.

It then becomes more energy efficient as the roof absorbs less heat. In the long run, you’ll be able to save more on electricity costs due to lesser energy consumption.

Top 4 Most Popular Flat Roofing Systems

parts of a roof
Building owners can choose from several different options when choosing a roofing system.

After learning about the parts of a roof, it’s now time to go ahead discuss what makes up an effective commercial roof — or the roofing systems.

Many people want to know what roofing systems to choose for their Youngstown OH property. We’ve shortlisted below four of the most popular options:


Metal has slowly become a frontrunner in the commercial roofing industry. This is attributed to its stability, strength, and longevity. As a matter of fact, a metal roof can last for up to 50 years with minimal maintenance requirements.

Many homeowners also consider metal for their properties because of its energy efficiency. The material itself doesn’t retain or absorb heat. It has the capacity to reflect sunlight that results in cooler indoors.

If there’s a balanced temperature inside the building or facility, you could lessen the use of cooling equipment. As a result, you’ll be able to lower your energy consumption and save more on utility costs. This lessens the urban heat island effect as well that affects many cities all over the world.

There are several types of metal that can be classified according to their price point, performance, quality, and appearance.

  • Aluminum – $4 to $6 per square foot
  • Steel – $7 to $ 10 per square foot
  • Zinc – $10 to $20 per square foot
  • Copper – $15+ per square foot

While metal is fire and rot resistant, it can be prone to rust. However, there are roof coatings available in the market to protect it from rust and other external threats.

Built Up Roof (BUR)

BUR is made up of tar and gravel and is one of the traditional options for commercial roofing.

In fact, it has been used for around 100 years already.

It can be difficult to install because of its weight and composition, hence, only trained experts are advised to handle BUR.

On the other hand, it is known to be extremely durable and waterproof. However, the material has a tendency to shrink over time due to varying factors. One of them is long-term UV ray exposure.

To combat this, you need to closely monitor the condition of your roof. To do this, engage in professional maintenance programs regularly.

Related: Why Commercial Roofing Maintenance is Important This 2020

Single-Ply Membranes

  • Modified Bitumen – this material is reinforced with polymer or fiberglass to make it more weather-resistant and durable. Installation can be labor-intensive and dangerous as it makes use of a blowtorch to completely attach the material on to the surface. The good thing about this is that it’s fast and easy to repair.
flat roofing installation using a blow torch
As seen in the photo, only well-trained roofing professionals can handle modified bitumen installation. Otherwise, it will not only result in a poor outcome but can also be risky and dangerous.
  • Polyvinyl Chloride (PVC) – this is ideal for large surfaces. PVC, a waterproof material, is also resistant to fire and UV rays. Some manufacturers reinforce it with titanium dioxide to increase its protection against sunlight.
  • Thermoplastic Polyolefin (TPO) – this single-ply membrane is a plastic-based material. It can effectively retard flame and reflect UV rays as well.
  • EPDM or Rubber – this is a synthetic waterproof membrane composed of recycled rubber. The materials are seamed together to produce an eco-friendly roofing system. Most EPDM roof owners complain about leaks and punctures. This can be avoided through scheduled inspections and maintenance procedures.

Mastic Asphalt

This is also considered a traditional roofing system used both for commercial and residential use. This has a proven track record when it comes to strength and longevity. In fact, it is also used in large-scale construction projects like dams, bridges, roads, etc.

The only thing with asphalt is that it can be labor-intensive and difficult to handle. Workers need to prepare and build reinforced joints to support mastic asphalt.

Mastic asphalt is a low-cost roofing system. However, expenses can significantly increase due to labor requirements.

Wrapping Up

It’s important to learn about the parts of a roof. It introduces you to the layers that make up a commercial roofing system.

Truly, it’s not enough that you know the material. As a hands-on owner, you need to fully understand how it works as a whole.

If you want to know more about commercial roofing system, feel free to reach out to our team.

J&M Roofing System is the most trusted Ohio-based licensed roofing company. You may also check out some of our recent projects or read what our clients have to say about our work.

You will also receive a free estimate if you dial this number today: 800-773-1616