Commercial property owners have the liberty to choose which type of roofing they want to go for. Among the many possible options, they usually end up with a flat roof. For some, this is a non-negotiable when it comes to commercial constructions. You may be wondering why are flat roofs common on commercial buildings? This is not a mere tradition that contractors and property owners follow. Surely, there is a logic behind it.

commercial property

Flat roofs go above and beyond when it comes to flexibility and functionality. Although it may not be as appealing as residential roofing, it is more beneficial for commercial use.

A flat roof has benefits that a pitched or sloped roof cannot deliver. It may not be visible at one glance but a flat roof is not entirely flat. It has slight pitches and slopes to drain water. To give you a more thorough explanation, we have identified 3 points to highlight why are flat roofs common on commercial buildings.

1. Cost

Contractors and property owners alike are drawn to flat roofs because they are the most cost-effective option available. Due to its straightforward design, flat roofs require fewer materials to build. The amount of labor is also reduced substantially. However, it is important to note that like any other roofing, it is still a major investment to make.

Price ranges vary depending on which material you decide to use. Remember that each type has their own pros and cons.

  • Felt

Costs about $0.38 per square foot. green roof commercial roofing

This type of flat roof is most commonly utilized for garage and sheds. The base is composed of natural materials like wood cellulose coated with bitumen (asphalt). It may be the cheapest but it has certain limitations when it comes to durability, aesthetics, and longevity.

  • Rubber or ethylene propylene diene monomer (EPDM)

Costs around $0.80 per square foot.

Rubber is both waterproof and lightweight which can withstand an inclement weather for many years. It requires careful installation to completely seal the edges as well as other details. When seams are not attached properly, it will break down after 5 to 7 years.

  • Asphalt

Costs $2.50 to $4 per square foot.

Mastic asphalt is naturally black. It is a mixture of several materials including aggregate, sand, limestone, bitumen, and some more additives. Characterized by its unbeatable durability, it is widely used for any type of construction (roads, pavements, bridges, parks, buildings, etc.). It is waterproof and has a lifespan that extends up to about 50 years. There is a need for regular maintenance but you can easily have it repaired by sections.

When choosing asphalt for your flat roofing, make sure you have strong structures to support its weight.

  • Tar and Gravel

Costs about $4 per square foot.

Among all the choices, this is the sturdiest and heaviest. It can effectively withstand extreme weather conditions lasting from 20 to 40 years.

  • Thermoplastic Olefin (TPO)

Costs $5 to $6 per square foot.

TPO is known to be fire-retardant with an average lifespan of 20 to 30 years. It also has great insulation properties.

  • Polyvinyl Chloride (PVC)

Costs $6 to $9.5 per square foot.

With its proven durability, it can resist chemicals and other external pollutants. It is an ideal choice for people looking to install long-lasting and high-performance roofing material.

  • Metal

Costs $15 to $60 per square foot.

It is the most expensive option for good reasons. Being lightweight, it is easy to install. You can save up to 30% on heating and cooling expenses. It is also capable of reflecting UV-rays and resisting fire.

Before selecting which one, it is best to do a bit of research to know what fits you best. Also, it is important to seek expert opinion from a trusted contractor.

2. Maintenance

Almost all types of roofing need proper maintenance to ensure that they last and prevent potential damages. Flat roofs are not an exception but they are less complicated to maintain.TPO Roofing membrane

When it comes to inspections, you can access a flat roof faster as compared to a pitched roof which can be riskier. Walking on it is also less complicated. Thanks to its flat surface, it is also easier to spot roofing problems such as leaks and damages.

A flat roof’s lifespan is expected to last within 20 to 30 years provided that it receives the right maintenance. It is also quicker to facilitate repair, replacement, or installation if there is a need for it.

3. Convertible Space

convertible space roof

  • Parking Space

Commercial properties are often situated in urban areas. Due to this, contractors and business owners want to completely maximize area assigned for the construction. In residential areas, homeowners can reserve parking space for 1 to 2 vehicles they own. But when it comes to commercial properties, parking space often becomes a huge challenge.

This is one of the top reasons why are flat roofs common on commercial buildings. You can convert the empty area into added parking space. It eliminates the need to find a new area for parking purposes which saves you more money.

  • Extra Storage

Storage is very important for business owners. No matter how space-saving the rooms are, there will always be excess equipment and supplies. Good thing, flat roofs are spacious enough to act as a storage area.

There are people who install their air-conditioning units above the flat roof surface which is also strategic. If placed this way, it is easier to perform check-ups and cleaning services.

  • Solar Panels

Flat roofs are ideal for business owners who are shifting to eco-friendly options. You can mount solar panels above the flat roofing area as an alternative source of electricity. This is not only helpful to the environment but is also good for saving extra money from electricity bills.

solar panel roofing system

Installation of solar panels demands expertise. If poorly installed, it can cause leakage and damage to the roof.


Why are flat roofs common on commercial buildings? Cost is the upfront and most obvious reason. Apart from this, commercial property owners utilize flat roofing systems simply because the possibilities are endless.

Aside from typical uses, there are people who explore converting it into gardens, penthouses, event spaces, etc. It can generate additional income or even lower expenses depending on how you intend to use it. As with any roofing system, installation is crucial as it could determine longevity and durability.

Cox Roofing Systems has over 30 years of experience in handling commercial property roofing needs. We are committed to safety, quality, and highest environmental standards. We aim to produce the best most energy efficient roof system to match your requirements.

If you need further assistance on commercial property roofing, you can reach us at 877-655-4054.