How much does a Commercial Roof Replacement Cost?
June , 2022 | 13 min. read
Got an older commercial property that is getting close to needing a new roof or maybe you have been dealing with some pesky roof leaks and just know it’s getting close to time to do a full commercial roof replacement.
So here you are, searching the internet and looking to get some idea of what the roof will cost you.
I am assuming you are a commercial property manager or a commercial building owner, right?
Well, let me assure you that you have not landed on Venus or Mars, we all know this internet thing can get weird sometimes!
But you are actually in the right place!
We have been designing and performing commercial roof replacements for our clients here at RoofCrafters Roofing for nearly 3 decades, so I can assure you that we know how exactly much they cost and I am happy to share my 29 years of experience with you in hopes that you will make the best and a well-informed decision about your upcoming commercial roof replacement project.
So, in this article I am going to cover:
- The 3 types of commercial roof structures
- The 5 most common types of commercial roof systems
- The average cost for a commercial roof system
And I can promise you that by the end of this article you will be well informed on all things related to commercial roof replacement. We want to help educate you so you can make the best decision on how you should proceed with your next commercial roof installation.
So let’s dive right in.
Types of Commercial Roof Construction
There are 3 main types of roof designs used for constructing a commercial building.
- Flat roof commercial construction
- Low slope commercial construction
- Steep slope commercial construction
Flat roofs in commercial construction are very common, it allows commercial engineers and commercial architects more options. Such as mounting rooftop mechanical equipment and the reduced structural requirement that comes with steep-sloped construction.
Flat roof construction requires your local commercial roofing contractor to slope the roof using tapered insulation so there is no ponding water on your roof surface. The tapered insulation also provides the building a higher R-value which will reduce the thermal resistance and help make your building more energy-efficient. This tapered insulation will also impact the overall cost of the flat roof replacement or installation.
Low slope commercial construction is where your commercial engineer or architect has designed the commercial building so that the roof already has a positive slope built into the construction of the roof framing structure. This slope creates positive drainage and allows the water to properly drain from your roof.
The downside to low slope construction is that this is not always a good fit for all the different types of commercial roofing materials that are available.
For example, a low slope roof that has metal installed has rooftop equipment such as HVAC units or skylights is typically not the best option.
Choosing an inferior roofing material can result in early roof leaks and create maintenance issues that another low slope roof system would not have on this type of commercial low slope roof construction.
A steep slope commercial construction roof on a commercial property is identical to or very similar to residential construction. The most common commercial construction types on steep slope commercial roofs are gable roofs or hip roofs. Gable and hip roofs on commercial buildings are constructed with metal or wood trusses. They can also be custom framed using wood 2x framing material.
The most popular roofing materials installed on commercial steep slope roofs are standing seam metal roofs, screw-down roof systems, metal shingles, Spanish tile, and asphalt shingles.
Now that you know about the different types of commercial roof construction let’s talk about the top 5 types of commercial roofing products.
Top 5 Commercial Roof types installed on Commercial Buildings
- Single-ply roofing (TPO, PVC & EPDM roofing)
- Modified Bitumen (rubber roofing)
- Built-up roof (hot tar roofing)
- Metal Roofing (standing seam & screw down)
- Asphalt shingles (upgraded shingles)
Single-Ply Roofing (TPO, PVC & EPDM roofing)
Single-ply roofing is one of the most popular roofing materials used on commercial flat or low sloped roofs. Single-ply roofing is available in different thicknesses. This is to help provide options to help meet your budget and lifespan requirements.
The higher the number, the thicker the product. The thicker the product the longer the manufacturer warranties their single-ply roof material.
Single-ply TPO and PVC roof is made up of 3 layers. A base layer, the scrim layer(reinforced woven fiber layer), and thickness over the scrim layer, which is the top layer. This top layer protects the scrim layer from the sun’s harmful UV rays.
An EPDM roof comes in a 45 or 60-mil thick membrane. The difference is the laps and flashings on this commercial roofing material are glued or seam taped together instead of hot air welded like the TPO or PVC single-ply materials.
The advantage of single-ply roofing is they come in white which makes them heat-reflective and energy star rated. They’re also lightweight, fire-resistant, provide a high wind rating, and are resistant to chemicals and pollutants which can be important in commercial and industrial roof applications. Single-ply roofs are also easily repairable and easy to keep maintained.
The disadvantages of single-ply roofs are they are not the most aesthetically pleasing roofing to look at. High foot traffic could pose a threat if the contractors are not mindful when performing work on the roof, dropping hand tools or screws and walking on them could puncture these roof systems.
Modified Bitumen (rubber roofing)
I like to say a Modified bitumen roof is the second generation of commercial flat roofing. Built-up or hot tar is the OG of the flat roofing materials and we will discuss that in the next section. Modified bitumen became popular because unlike the hot tar roof that requires setting up a hot tar kettle mod-bit does not.
The roofing industry has been moving away from hot tar roofing. Modified bitumen roofs can be installed with hot tar but the most popular installation methods are without the hot tar.
Here are 4 main installation methods.
- Hot tar applied
- Cold tar applied
- Torch applied
The last 3 installation methods, cold tar applied, torch applied, and self-adhered have made modified bitumen roofs more efficient for commercial roofing installations.
The advantages of Mod-bit roofs are they have multiple layers and having multiple layers can make them more durable. This increased durability can make the mod-bit a better choice for commercial roofs with high foot traffic.
The disadvantages of Mod-bit with these multiple layers are the cost of the materials and the labor to install multiple layers is more expensive. Also performing repairs and maintenance on mod-bit roof systems can be more difficult, increasing the cost.
Built-Up Roof (hot tar roofing)
A built-up roof can be your best friend or your worst nightmare. There are so many variations or layers of roofing materials that make up a built-up roof system.
Layering the materials is how it got called a built-up roof. The roof is built-up by layering plies of fiberglass rolls of roofing and hot tar between each layer. And this is only the short explanation of how it gets installed.
The basics of a hot tar roof so to speak. It’s asphalt heated up to 500 degrees and then we mop that directly on the roof deck or insulation. Yep, just like you would mop a kitchen floor. And in-between mopping we roll out layers of roofing while it's still hot. Many built-up roofs are done with 4, 5, or 6 layers of roofing.
The top layer is the most important layer when it comes to maintenance. It will be what determines if it can be repaired and maintained successfully. Oftentimes the top layer is a flood coat of hot asphalt (tar) with rocks put in the tar while it is still 450 to 500 degrees. A hot tar roof with a rock finish makes for a challenging repair for a very experienced roofer. But it can be done if there is useful life left in the flat roof system.
Now, if it has a granule surface cap sheet as a finish layer or an asphalt flood coat, it is much more manageable to maintain and repair. Either way, the existing materials that will need to be maintained need to have some useful life left to make any repairs that will last any length of time.
The advantage of a built up roof system is they last 20-30 years. They are very durable, so heavy foot traffic will not damage this roof system.
The disadvantage is the cost, having to install multiple layers means we roof the building multiple times to get one roof system. Heating up asphalt and pumping it up on the roof is also a very dangerous job.
Metal Roofing (standing seam & screw down)
Metal roofing is another popular roofing option for commercial buildings.
There are 3 main types of metal roof systems:
- Standing seam
- Metal shingles
Standing seam is a concealed fastener metal roof system and screw-down is a metal roof with an exposed fastener through the metal roofing. Both metal roof systems have their advantages and disadvantages.
The advantages of the standing seam are their longevity, being installed correctly they will easily last for 50+ years, they also provide a very high wind rating, and they don't blow off in severe wind storms.
Standing seam metal looks great on commercial buildings and adds value to almost any commercial property.
The disadvantages are they cost more, because of the attachment method it takes longer to install and requires a much higher skill level to install the flashings for this system.
The advantages of the screw-down roof are they are cheaper and still provide the curb appeal of a metal roof. The disadvantage is they require maintenance within the 5-year mark. With all the expansion and contraction(thermal movement) that happens with all metal roofs, the exposed screws can come loose and of course, they do.
Metal shingles are very popular as they can be made to look like real wood shakes, real slate, and real Spanish tile roofing. All of the natural products require more maintenance than the metal shingles require making these a very popular choice for owners looking for longevity and the extra added curb appeal.
There are 3 types of metal roof materials that are commonly installed on commercial buildings:
There are other metal material options however these 3 metal roofs are all durable and cost-effective. They offer a wide range of aesthetic looks, longevity, and price ranges too.
All of these commercial metal materials are available in standing seam metal or screw-down metal profiles as well as shingle, slate, wood, and tile metal roofing style profiles.
Aluminum metal roofing
Aluminum is one of our most natural energy efficient metal roof materials available. Aluminum metal comes in different thicknesses and typically for roofing we use a 032, 040, or 050 thickness. The higher the number the thicker the aluminum roofing will be. The 032 and 040 thicknesses are most popular on commercial roof installations.
Aluminum comes in a mill finish or a painted finish.
Mill finish will provide you with a raw metal look and it will oxidize into a naturally beautiful raw metal finish. Aluminum comes in a wide variety of painted finished colors too. Most of the paint finishes come with a 40-year paint warranty with some manufacturers even providing a 45-year paint finish warranty.
Steel metal roof
Steel roofing is the most popular metal roofing material used for roofing commercial buildings. Steel metal is galvanized steel that is hot dipped or coated in a zinc coating. Steel is less costly and can be as effective and efficient as any of the other available metal materials.
The steel material is very popular for roofing and comes in 24 gauge, 26 gauge, and 29 gauge. Don't get fooled, unlike aluminum, the lower the number the thicker the steel roofing will be.
4 of the most common steel roofing profile that is used on commercial roof installation:
- Standing seam metal panels (12”-18” wide panels, concealed fasteners)
- Interlocking steel shingles (slate or shake look, concealed fasteners)
- 5-V crimp metal roofing (2 foot wide panels, exposed fasteners)
- R-panels or multi-rib panels (3 foot wide panels, exposed fasteners)
Because steel is not a non-corrosive metal, these metal roofing materials require a paint finish. Paint finish warranties range from 20-years to 45- years depending on the thicknesses, type of panel, and the manufacturer of the metal.
Steel metal roofing is very cost-effective and offers a wider range of prices depending on which profile you choose, the thickness of the metal, and the paint warranty available.
Galvalume metal roof
Galvalume metal is also a metal that has a steel core and is coated with aluminum to prevent corrosion.
Galvalume is much like steel roofing and comes in the same thicknesses, 24 gauge, 26 gauge, or 29 gauge. It is also available in all 4 of the different panel profiles.
The main difference with galvalume is that it comes as a mill finish metal product, so it is not available in a painted finish. This makes it slightly less expensive and easier to work with as the painted materials can get scratched during installation if not handled carefully.
It is also a great option to use around the ocean or if you live anywhere near the saltwater.
Asphalt Shingles (upgraded Shingles)
Yes, even though shingles are mainly used on residential homes, they are probably on your home and they are definitely on my roof at home.
Well, it is not uncommon for asphalt shingles to be installed on commercial buildings too.
The shingles we install on commercial buildings are not the basic builder grade shingle that is installed on new construction homes. The reason for this is that builder-grade shingles provide the least wind protection and they require replacing as early as 10 to 12 years. Builder grade shingles also provide the least curb appeal.
Upgraded shingles, designer or luxury shingles are more widely used on commercial buildings. They will provide you greater wind protection, enhanced curb appeal, and upgraded shingles that can last 25 to 35 years.
The disadvantage of shingles is they don't last as long as the metal roofing and when it is time to replace the roof, it can be messy for a building with commercial use.
Now that you know the 5 most common types of roofing installed on commercial buildings let's go over the cost of a roof replacement using each of the 5 we have discussed.
The Average Cost for a Commercial Roof Replacement
- Single-ply roofing, the average cost is 7.50 to 13.50 per square foot
- Modified Bitumen, the average cost is 9.50 to 15.75 per square foot
- Built-up roof, the average cost is 12.50 to 22.25 per square foot
- Metal Roofing, the average cost is 12.50 to 18.75 per square foot
- Asphalt shingles, the average cost is 4.50 to 8.50 per square foot
As you can see the cost for a commercial roof replacement will vary depending on which type of roof best fits your specific needs and the overall look or style that you prefer.
If you are ready to get an exact cost for your commercial roof replacement our team here at RoofCrafters is here to help. With over 30 years of combined experience installing commercial roofs, we would be happy to help you select the right roof for your next commercial roof replacement project.
If you are ready to get started, schedule your inspection.
At RoofCrafters, our mission is to provide job opportunities for others to thrive and grow while making a meaningful impact within our communities.