Types of Commercial Roofs

Green Roofing Systems, Thermoplastic Roofing, EPDM

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Commercial Roofing Systems

There are many different types of commercial roofs all with benefits and disadvantages. If you are in the process of building a brand new building, or you are replacing a new roof with an existing one, it's a good idea to find out what the different types of commercial roofs are, and then figure out the different pros and cons so that you can make a sound decision before spending all that money on one. Here we will be looking at the three primary types of roofs, as well as benefits and cons of each one, and a few other statistics and pieces of information. If you’ve read this article and are still confused about the best type of commercial roof for your building you should contact a commercial roofer with any questions. Roofing contractors have decades of experience in roof installation and repair and they are able to answer all of your roofing questions.

Green Roofing Systems

Green roofing systems are a thing of the future, but these days more and more people are using them for commercial buildings. A Green Roofing Systems can be incredibly beneficial. These can help to reduce summer temperatures inside the building, and also improve air quality outdoors by almost eliminating air pollution and greenhouse gasses, but they are also a superb way to promote biodiversity. When it comes to green roofing systems, there are a few different types according to the IGRA – the International Green Roofing Association.

- Extensive Roofing Systems: These types of roofs use a thin membrane to cover the roof and then it also includes a small growth mixture of plants and soil. These also tend to include plants that are drought tolerant, which makes them perfect for drought inclined locations, as well as tropical areas. These plants will add options such as herbs, mosses, grasses, and succulents.

- Semi-Intensive Green Roofs: These have a deeper layer of soil on the roof and instead of the usual suspects above, you will see things like lavender, herbs, flowers and grasses. This type of a roof does NOT have bushes or trees, however.

- Intensive Green Roofs: Now for this option, it’s using deep soil layers and it can include things like grasses, flowers, bushes, and trees. Obviously for something like this, its quite lovely to look at and offers green friendly options, but since it is so heavy, you will need additional braces and support beams to keep it all balanced and steady.

Thermoplastic Roofing Systems

Thermoplastic Roofing Systems or TPO as its more commonly called is a type of membrane roofing that is often used in commercial buildings – it can also be used on house roofs, but it's more commonly used in commercial building applications. This is a single ply membrane and is very much like EPDM roofing. However, Thermoplastic polyolefin is quickly replacing EPDM. This is still pretty new technology, only about ten years old, but over the next few years, it will be the go-to choice for most buildings. Thermoplastic polyolefin comes in rolls that are available up to 12 feet wide, and 100 feet long, and it also comes in three primary colors; white, black and gray, but white is the most popular considering its UV protection properties.

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How Are Thermoplastic Roofs Installed?

When you get a Thermoplastic polyolefin roof, it can be installed one of three ways:

- An adhesive is applied – essentially the roofing material is “glued” down onto the roof.

- Ballasted: When an item is ballasted, it is essentially, weighed down. In the case of this Thermoplastic polyolefin roofing membrane, they can be held down using rocks, pavers, bricks, etc. which can be placed on top of the Thermoplastic polyolefin roofing.

- Fasteners: Another option is for them to be fastened down with screws or screw-like fasteners – this is by far and wide the most popular choice.

Thermoplastic polyolefin vs. EPDM

There is a lot of talk about which roofing option is better; Thermoplastic polyolefin or EPDM, below is a side by side comparison of these materials and which one is better.

Seam Strength

The seam is essentially one of the more important parts of a roof, with the seem intact; you add an extra layer of protection. In pounds, EPDM offers between 10-20 lbs of seam strength. On the other hand, Thermoplastic polyolefin offers50 pounds plus. One of the amazing things about Thermoplastic polyolefin is that the seam can be hot air welded which means the commercial roofer in Orange County can use a weld to weld the seams together – this allows for an unyielding seal against the weather. In fact, in many cases, the seam can be stronger with Thermoplastic polyolefin than the actual material itself.

Puncture Resistance

Lets be honest, it’s a roof, but chances are you do have people that go up to the roof to maintain it, you have HVAC systems, etc. There is always a chance that your roofing material can be punctured. Thermoplastic polyolefin offers 250 plus pounds of puncture resistance – one of the best. EPDM 80 mil reinforced only offers 215 pounds of resistance and 80 mils non-reinforced EPDM only offers 100 pounds. That’s quite significant if you think about it!


If you are hiring a commercial roofer in Orange County the installation probably doesn’t mean too much to you personally. But, if this is a DIY job and you are doing it on your own, the ease of installation is an important aspect of the roof material itself. So it should be noted that EPDM takes about 12 steps to install it – more room for error, especially if you’ve never done this before. But, Thermoplastic polyolefin takes a mere three steps to getting it installed. Not only is this perfect for the DIYer, but it also makes for easy repairs (and inexpensive) as well.

Cost and Energy Efficiency

Black is NOT the most energy efficient color (white is) but for this particular example, we will be using black Thermoplastic polyolefin versus black EPDM. On a sweltering day, a black roof can quickly reach 170 degrees. Using a black roofing material made from Thermoplastic polyolefin can lower your temperatures of the roof all the way down to 110 degrees. Also, because Thermoplastic polyolefin has different colors, including those that are energy star qualified, namely white, you can expect even a lower temperature when the sun is scorching.

Metal Roofing

Another very popular option for roofing in commercial buildings is a metal roof. Metal roofs can be made from an array of metals including steel, metal tile sheets, aluminum, and even copper, each one has its benefits as well as disadvantages, though. For example, steel can offer extra strength and durability, but it's also incredibly heavy and they tend to rust – if you want a steel roof, just like with any other material here, you will have to take a few extra steps to make it rust-free such as an epoxy layer. When you buy a metal roof, make sure that it’s labeled by either UL, FM Global, etc. UL: UL is one of several companies approved to perform safety testing by the US federal agency Occupational Safety and Health Administration (OSHA). OSHA maintains a list of approved testing laboratories, which are known as Nationally Recognized Testing Laboratories. FM Global: FM Approvals is a leader in certification and approval of roofing products and roof assemblies. Their product Approval is based on performance testing of completed assemblies when subjected to multiple perils. A typical FM Approvals program includes fire testing above and below the deck, wind-uplift testing, hail-damageability testing, accelerated weathering testing, and corrosion resistance testing of ferrous metal parts.

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Benefits Of Metal Roofing

1- Longevity: Metal roofs can last a long time. In most cases, unless they are under extreme temperature coverings, they can last anywhere from 40 to 70 years easily. Something like a traditional asphalt roof will last much less, about 12 to 20 years long.

2- Durability: Depending on the metal you choose to use, the durability levels can be incredibly high. For example, some metal materials can withstand wind gusts of up to 140 miles per hour! Some will also not corrode or crack, and others can also be impact resistant. These roofs will also need less maintaining, but periodic maintaining should still be done – nonetheless it is less costly than other materials.

3- Safety Issues: If you live in a location, such as California, where you get a lot of wildfires, a metal roof is perfect because it won't burst into flames with fire – also it won't ignite during lighting storms.

4- Energy Efficient: You have a lot of materials and technology these days, such as the TPO above which is energy efficient, but when it comes to actual materials like tar, glass, metal, etc. metal is by far the most energy efficient. In fact, it's said to cut cooling costs by 10to25%!

Negatives To Metal Roofing

Every single material or system out there has its benefits and disadvantages and metal roofs are no different. Here are a few negatives to this type of a roof.

1- Expensive: Can metal roofs last a long time? Yes. Can they withstand a lot of weather elements? Yes. But, are they expensive as well? Yes. Of course, if you are willing to look at the bright side and have the budget for a metal roof, its well worth it. If you don’t have a great budget, it might be time to look at something else.

2- Noisiness: If you’ve ever been in a building with a metal roof, you know that they are incredibly noisy, so it doesn’t matter if it's a shack, a farm house, a storage building, a house or commercial building – they will all be noisy if you have rainstorms. You can try to add more insulation which can help lessen the noise, but this will also add on to more costs for the project.

3- Performance: Just like with any other material or roofing system, pooling can happen especially if you don’t have the proper installation. To fix this, you will need to find a commercial roofing contractor that can do the job right the first time around because if not, you are going to have issues shortly with pooling. On top of that, you need to find a commercial roofing contractor that will offer repairs when necessary because this is a finicky material. Even more finicky when its low-grade quality – you will need more repairs and replacements for a second-rate quality metal roof, than one that is high-grade quality. Something to consider.

Hopefully, this gave you a few options to consider that would be a good fit for your budget, the size of your roof, and, more importantly, your location. If not, there are some other options available, but they are much less commonly used so make sure that you do your research and talk to a commercial roofing contractor about the different options available and which ones would fit your needs. Some of those “other” options include; SPF, bitumen, and single ply roofing systems. SPF: Spray foam insulation is an alternative to traditional building insulation such as fiberglass. A two-component mixture composed of isocyanate and polyol resin comes together at the tip of a gun, and forms an expanding foam that is sprayed onto roof tiles, concrete slabs, into wall cavities, or through holes drilled in into a cavity of a finished wall. Asphalt also known as bitumen is a sticky, black and highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product; it is a substance classed as a pitch. Until the 20th century, the term asphaltum was also used.