Commercial Roofing: A Quick Guide

flat roof on commercial building

Most people don’t realize the importance of understanding the difference between residential and commercial roofing. Residential and commercial roofing are two different industries that should be handled differently. Things that work for commercial roofing might not work for residential and vice versa.

The things that differentiate these two industries are the use of material and the slope of the roof, which is determined by the size of a building. Residential roofs typically have a steep slope and use shingles, wood, slate, and steel. On the other hand, commercial buildings tend to have flat roofs and commonly use BUR (Built-Up Roofing), PVC (polyvinyl chloride), TPO (thermoplastic polyolefin), EPDM (ethylene propylene diene methylene), metal, and modified bitumen.

To help you choose the right one for your business, we have provided a short but comprehensive guide on everything you need to know about commercial roofing.

What is a Commercial Roof?

A commercial roof is a type of roofing system that is commonly used on commercial buildings. Though the primary function is to protect the property, the use of material and style makes each system unique from the other.

Basically, there are two types of roofs, residential and commercial roofing. Residential roofs are used for regular private homes, whereas commercial roofing is used on commercial buildings and layouts.

Common Commercial Roof Styles

Unlike residential houses, commercial buildings are large and wider in area. As per the needs and the structure of commercial buildings, commercial roofs mainly fall under three types of styles.

  • Flat – Since 1920, flat roofs have been the most common roofing system for commercial buildings and industrial commerce. Before the use of flat roofs, pitched roofs were used for both residential and commercial buildings. The reason why commercial building owners and builders shift to flat roofs from pitched roofs is that they are cost-efficient, require less material, and are easy and quick to install. Flat roofs also offer space to install air conditioners, solar panels, and satellite dishes. Maintenance and drain cleaning are also easier on flat roofs since workmen can walk safely, regardless of weather conditions. The only disadvantage of this type of commercial roofing is the poor drainage system. They don’t have good drainage systems compared to slope or pitched systems.
  • Low-Sloped – A commercial, low-sloped roof is commonly used in factories, warehouses, apartment buildings, and other industrial layouts. Most people find it hard to differentiate between flat and low sloped roofs because they look the same. However, that is not the case. The low-sloped roofs appear to be flat but they actually have a slight pitch. The material used on flat roofs can also be used on low-sloped roofs. Similar to a flat roof, a contractor can also safely work on this commercial roof type. Air conditioners, solar panels, and satellite dishes are easier to install and maintain on low-sloped commercial roofs than on others with a higher pitch. Also unlike flat roofs, low-sloped roofs give a better drainage system. The only potential issue with this style is that heavy snow doesn’t melt as quickly, which can add extra weight to the commercial building.
  • Pitched – Pitched roofs are mostly used for residential as opposed to commercial roofing. The advantage of using a pitched roof for commercial buildings is it provides a greater runoff for water and snow. Though the pitched roof provides a better gutter system and is commonly used for residential roofing, it is usually not the best choice for a commercial project. When it comes to commercial roofing, pitched roofs don’t quite offer the full potential as flat and low-sloped roofs. You can’t perform easy repair and maintenance nor can you install AC, solar panels, and satellite dishes.

Types of Commercial Roof Materials

Commercial roofing offers a wide variety of materials to choose from. They also offer different colors, shapes, and sizes.

  • Spray Polyurethane Foam – Spray polyurethane foam (SPF) is a liquid form material that when sprayed expands into a foam, creating a solid layer across an existing roof. The materials that are used for SPF roofing systems are environmentally friendly: Zero Ozone Depleting Potential (ODP), Low in the Emission of Volatile Organic Compounds (VOCs), Free from Chlorofluorocarbons (CFCs), Ultra-Low Global Warming Potential (GWP). One good thing about this roofing system is, when correctly installed and maintained, it can last over 50 years. SPF is very energy efficient, seamless, and waterproof.
  • Single-Ply Membrane Roofing – A single-ply membrane is another great commercial roofing option. These roofing materials are sheets of rubber that are synthetically ballasted and mechanically fastened to create a protective roof layer. Single-ply membrane roofing can be either thermoset EPDM roof membrane or Thermoplastic PVC & TPO roof membrane. The average lifespan of a single-ply membrane roof is 30 years. Similar to SPF, single-ply is also class A fire-rated commercial roofing material.
  • Shingles – Shingles are not the best material for commercial roofing but it offers a wide variety of colors and design. It’s easy to repair and durable. If that’s what you’re looking for, a shingle roof might be an option. Shingles are made of different materials including wood, slate, metal, plastic, ceramic, and composite. It is mainly used on steep slope commercial roofing.
  • Built-Up Roofing (BUR) – Built-up roofing is commonly known as “tar and gravel” roofs and has been around for over 100 years. It is composed of alternating layers of reinforcing fabric and bitumen (asphalt) and is finished with a top layer of aggregate, such as stone or gravel. You can choose the number of layers that are installed. If properly installed and maintained, BUR can last up to 40 years. It also provides ultra-violet protection, does not require a seam, and minimum maintenance is needed after installation.
  • Metal – In the current industry, a metal roof has become very popular for both residential and commercial roofing. Metal is lightweight, can be installed on top of an existing roof, and can last up to 50+ years. Metal is energy-efficient, eco-friendly, durable, sustainable, fire-resistant, and comes with a variety of material and color choices.
  • Green – A green roofing system is an extension of the existing commercial roof which involves, at a minimum, high-quality waterproofing, a root repellent system, drainage system, filter cloth, a lightweight growing medium, and of course, plants. This system is not simply sod thrown across the surface of the roof. Instead, it may be modular, with drainage layers, filter cloths, growing media, and plants already prepared in movable, often interlocking grids. It may also be “loose-laid” whereby each component of the system is installed separately.

Common Signs You Need a Commercial Roof Repair

No matter what type of material you use for your commercial roofing, it needs to be repaired and maintained from time to time. Here are some common signs of commercial roof repair:

  • Moisture Problems – Sometimes when the roof is not installed properly, moisture can infiltrate the roof areas. If you see any sign of humidity, water stains on the ceiling, and an increase in insects or rodents, there is a huge probability of water leakage.
  • Climbing Energy Bills – As the roof ages, it starts to lose its reflectivity which leads to hotter rooms. When the rooms are heated up, your AC has to work harder which will in return increase your energy bills.
  • Bubbles – Bubbles are a common sign of repair on commercial roofs made of BUR and single-ply. While inspecting your roof, if you see multiple bubbles, it’s time to give your commercial roofing system a repair.
  • Open Seams – Open seams are a common problem for both residential and commercial. As the roof expands and shrinks every season, over time the chemical or mechanical fasteners start to loosen. You need to consider commercial roof repair when seams are no longer sealed. If not, water will find its way in.
  • Clogged Drains – When debris and dirt accumulate on the gutter system, it stops the water flow. And this often leads to ponding, which will eventually lead to water leakage.
  • Flimsy Flashing – Flashing is an important component of a commercial roof. If you see gaps, or if it’s dislodged or missing, you need to repair your commercial roof as soon as possible.
  • Punctures – Heavy objects such as stones, tree branches, and heavy hailstones can puncture your commercial roof.

Signs Your Commercial Roof Needs Replacement

Some of the commercial roof damage can be repaired but for serious damage, you might need to entirely replace your roof. Here are some signs that point towards replacement instead of repair:

  • Damaged Membrane – High winds and storm damage are the main culprits for roof membrane damage. If the damage to a roof membrane is 25% or more, your roof needs a replacement instead of repair.
  • Considerable Wear and Tear on the Deck – Deck is the most important component of a roof as it holds up the entire structure. Roof deck damage is not visible initially, so during an inspection, if you see moisture damage or wear and tear on the deck, understand that it’s time to replace your roof.
  • Visible Water Infiltration – If you see any marks or stains on the walls attic, there is a huge probability that water is leaking somewhere from the roof in a huge proportion. If you notice any of these signs make sure to inspect and replace them as soon as possible.
  • Your Property Isn’t Well Insulated Anymore – Insulation plays a great role in commercial roofing to keep the inside room cold. So if you notice your electric bills increasing even if your HVAC usage is normal, then it’s your roof that’s causing the trouble.
  • Your Commercial Roof is Old – On average, a commercial roof lasts anywhere from 20 to 30 years, so if yours is more than 15 years old, there is a high chance that it will be in need of constant repairs. Instead of repairing your roof month after month, it’s better to replace it entirely. It will cost you less and you’ll have no problem for the next 15 to 20 years.

Commercial Roof Repair vs. Replace

Whether to repair or replace your commercial roof depends on its condition. Repair jobs are a quick fix that is more affordable than a full replacement but not all damages can be fixed by repair.

Some major damages will need an entire replacement. Hiring a professional for inspection is the best way to figure out if the roof needs replacement or repair.

Benefits of a New Commercial Roof

Though repairs can fix lots of roof problems, roof replacement is far more superior to roof repair. Here are some benefits of installing new commercial roofing.

  • Improves the Safety of Your Commercial Building – As the world is getting modernized, there’s also been a significant improvement in the construction industry. Building designers are coming with new materials and construction techniques to improve the safety of a building. The existing roof that you have on your commercial building might be a decade old. Installing a new one will give you the opportunity to use the latest materials, which not only improves the safety of the building but also adds style.
  • Increase Your Commercial Building’s Storm Resistance – No doubt, new roofs are stronger than old ones. A new roof can withstand high winds, water damage, destructive storms, and heavy hail storms. Commercial roof replacement provides weather resistance for your roof in several ways. New flashing, joints, gaskets, and other installations provide water-tight seals for your entire structure. Properly fastened roofing materials have greater wind resistance.
  • Benefit From New Depreciation Rules – Under the new tax code created by the Tax Cuts and Jobs Act of 2017, you have more incentive than ever to replace your roof.
  • Increase Energy Efficiency and Sustainability – Today most commercial roofs come with roofing techniques that offer increased energy efficiency. A new roof has high UV reflectivity, meaning it reflects the sun heat double the time compared to an old roof. Having a cold indoor means low use of AC and low use of AC means low electricity bills. Modern commercial roofing also offers a green roofing option for commercial building owners who are concerned about climatic change and the environment. A green roof is also the best way to provide habitat for wildlife, stress relief for staff, and improved stormwater management. They also absorb rainfall rather than letting it flood gutters, downspouts, and storm drains.

Roof Inspection Checklist

There is a saying, “a stitch in time saves nine.” This quote goes very well when it comes to roof inspection. If you treat your roof damage at the right time it will save you lots of money in the coming days. Commercial building owners should do periodic inspections at least twice a year, if not at least once a year if they want to keep their roof healthy. Here are some inspection checklists to consider for your commercial roofing.

  • Inspect for Ponding Water – Ponding water is a major problem with your roof. While you inspect your roof make sure to check the areas where water ponding could happen.
  • Look at the Flashing – Flashings are thin metal strips that cover small holes and cracks between two roofs. It helps protect water from entering into the interior part of the roof. Make sure you don’t miss the flashing during an inspection.
  • Check for Any Cracks or Tears – Any signs of cuts or tears in your system will need to be found before structural damages are incurred.
  • Check the Edge Detail – The edge is often ignored and left unattended, nobody knows the reason. Maybe the edges are a dangerous part of the roof or are clearly not visible. Whatever may be the reason, keep it aside and make sure to inspect the roof edge. If you can’t do that, hire a professional contractor to do the inspection.
  • Inspect Surfaces – Check the roof surfaces to see if anything has blown loose or lifted because of wind damage.
  • Check the Gutters – Gutter helps to drain out water off your roof. If your gutters are clogged, water will be more likely to pool on your roof. To prevent this from happening, remove any debris that has built up in your gutters.
  • Look at Your Downspouts – Lastly, inspect your downspouts and make sure it’s working as it should. Sometimes, these sections become damaged or crushed from things like lawn maintenance to passing vehicles.
  • Costs of a Commercial Roof

Nobody can give you the exact cost of commercial roofing. Each contractor has its own term and price margin. And the cost of the commercial roof is also determined by the material used.

To give you an average cost, built-up bituminous flat roof replacement could cost anywhere from $3.50-$6.50 per square foot. The average cost for asphalt shingle roof replacement could be between $3.50-$7 per square foot. The average cost for metal roof replacement should be $7-$12 per square foot.

Factors That Determine the Cost of Commercial Roof

There are lots of factors that determine the cost of a commercial roof. Some of the factors are mentioned below.

  • The location of your building has a lot to do with the cost of the commercial roof. Due to differences in labor, materials, and building code regulations, costs on similar projects can vary by as much as 70% based on location.
  • The use of a building also determines the cost. For example, the roof of a commercial warehouse will be less expensive compared to an office building.
  • Each state in the US has different building codes. Depending on the types of building cost, a commercial roof can be either expensive or cheap.
  • The cost of the material keeps fluctuating each season, in winter the cost of the material goes up and comes down in the rainy season. The market factor has a lot to do with the cost of replacement.
Why You Should Hire a Professional Roofer

Trying to repair or install a commercial roof can cost you more than hiring a professional. Roofing jobs are dangerous and need to be handled by a professional. It’s wise to hire a professional instead of trying to do it on your own.

Here are some benefits of hiring a professional contractor for your commercial jobs:

  • Expertise and Experience – Professional contractors have worked in the roofing field for many years. They have all the right expertise and experience for the job.
  • Professionalism – The best business practices are born from experience, so a professional team will be better prepared to adapt to new situations, implement thorough safety procedures, answer questions quickly, and ensure your project is handled well.
  • They Follow Your City’s Building Code – Most commercial building owners don’t know the building codes. A professional contractor will happily guide you through the codes and tell you what can be done.
  • Advice on the Best Materials – A professional roofing contractor will give you advice and suggestion on the best material that fits your building style and your budget.
  • You Get a Warranty – Every roofing company knows what they are doing and to ensure the work is done right they will give a warranty. The duration of a warranty depends on the type and the material used.
  • Licensed – Most of the contractors are licensed which makes them even more credible.
  • Project Update – When you work with a professional you know what is going on up on the roof. Roofers will keep you up to date on the progress of the project.
  • Quality Service – You get a quality roofing service while you hire a roofing service.
A Better Way to Boost Your Business

If you’ve come this far in the overview, you’ve read about the myriad of roofing systems available for commercial roofing. While the choices are numerous, you may have narrowed it down to what best suits the needs of your project and budget.

Having a roof installed is one of the most major decisions you will make as a commercial building owner. If you pick the wrong one, you could end up roofless one day in the middle of a horrible storm. With that, it is important that you not only select the right quality of materials but also become knowledgeable about the whole thing as well. By doing so, you will be more equipped to advise your contractors about what you want your roof to look like.

Determining the best commercial roofing company for your needs can be complex, especially because replacing or installing a commercial roof is an expensive process, to begin with. So always, start with recommendations from fellow property owners!