THERE ARE MANY, POSSIBLY TOO MANY, FLAT ROOFING OPTIONS AVAILABLE TO BUILDING OWNERS TODAY
As a building owner, you have a ridiculous number of decisions to make and thousands of options available to you regarding your building. What color paint in the bathrooms, what type of paper towels in the break room, what type of roofing system do you want? With so many viable flat roofing options available out there today, it can become overwhelming to make a decision and feel confident about it. This difficulty in making a decision is oftentimes referred to as analysis paralysis, and it impacts most people that have to make decisions with multiple legitimate options. It’s extremely difficult for building owners and facility managers to determine what the best flat roofing material is, especially since the answer is different from one person to another. It all depends on what you need out of your roof and what type of system you currently have. If you’d like to figure out the best flat roofing material for your roofing system, we have three steps you can follow. If you want to let us do the heavy lifting, read on.
Let’s break down some of the most common flat roofing options, and provide you with some concise, down to earth information on each of them. Hopefully after reading through this post you will feel more comfortable about the decision you have made or will make in the near future, and will have a better idea of the best flat roofing material for your building.
Flat Roofing Option 1: Modified Bitumen
Modified bitumen is a single-ply flat roofing option that typically is installed by rolling materials directly onto the roofing surface. Traditionally, the material had to be rolled onto the roof and then heated with a blow torch to allow adhesion. In more recent years, the material has been manufactured so as to allow adhesion without the use of a blow torch. This new method is much safer and eliminates the danger of catching the roof on fire with a blow torch.
The biggest advantage of this roofing system is that it is reflective and sends a high percentage of the sun’s UV rays back into the atmosphere. Rather than absorbing the heat and transferring it into the building, this roof sends it back out, saving you money on your energy bills.
One downside related to this flat roofing option is that the material is not scuff or tear-resistant, and therefore cannot stand up to much foot traffic without showing signs of wear and tear. If your roof sees a lot of foot traffic, this may not be a good option for you as the roof will most likely deteriorate more quickly than other systems.
Flat Roofing Option 2: PVC
PVC roofing systems are very similar to TPO and are often bundled together as flat roofing options. PVC roofs are highly reflective, highly durable, and lacking in water permeability, meaning it can resist standing water if the seams are properly installed.
The most significant downfall of PVC and TPO roofing systems are the seams that come with the roofing system. As with modified bitumen, PVC roofs are installed in rolls that must be glued or taped together, as well as adhered to the roof. If these seams aren’t properly installed and adequately taped, they will leak water almost immediately after installation. Even if the seams are installed correctly, these are weak points of vulnerability and will more than likely lead to roof failure at some point down the road, even if they don’t leak at first.
Flat Roofing Option 3: Spray Applied Coatings
We are just looking at spray applied coatings in general, not any specific type. These could include acrylic, silicone, aluminum, polyurea, or other coatings. Each spray applied coating has its own strengths and weaknesses, and it is often to know which one is the best for your roofing system. Spray applied coatings are great flat roofing options for several reasons.
The first key advantage of spray applied coatings is their seamless application. Because they are spray applied, they do not have any seams. No seams mean no leaks. As long as the material is properly installed and there are no breaks in the coating that was applied, this is a completely waterproof roofing system.
Second, most spray applied coatings have a very strong resistance to ponding water. Even seamed materials that are installed correctly can succumb to ponding water after a period of time, but not spray applied coatings. Most of them are impermeable and completely resist ponding water.
The third advantage of this roofing system is its ease of application. Simply buy the material, apply with a spray gun, and you’re set to install. No tear-off, many times no primer required. The job is very simple when these coatings are used. This advantage and the two mentioned before it are why we believe spray applied coatings are probably the best flat roofing material available.
The major disadvantage of spray applied coatings is cost. As you may have already guessed, a system with so many advantages is bound to have a high price tag. The cost of the material is high, but so much money is saved on installation costs and with no need to tear out the old roofing system, these roofing systems typically end up costing less in total than other systems.
Flat Roofing Option 4: EPDM
This is another one of the single-ply flat roofing options, and is installed in a similar fashion to PVC. The most significant difference between EPDM and PVC is that EPDM is a rubber compound while PVC is plastic.
The greatest strength of EPDM roofing systems is that they are very durable. They have built a reputation around their durability and this is basically the only reason they have become as popular as they are.
However, despite their durability, EPDM flat roofing options are often the cause of many a headache for facility managers thanks to their seam system. Just like modified bitumen and PVC, EPDM roofs have seams that must somehow be adhered to one another, and the bond on these seams often fails, which leads to leaks and other failures of the roofing system.
Flat Roofing Option 5: Built-Up Roof (BUR)
Built-up roofs are one of the less expensive flat roofing options available. They are typically constructed out of several layers of roofing material with tar and gravel at the top layer. Thanks to their many layers, they are both extremely heavy roofing systems that require a lot of support, as well as extremely good insulators that can save on energy bills.
Another nice feature of BUR’s is that they are aesthetically pleasing. If you have a building that people can see or that gets a lot of foot traffic, this is a fun roof to have because of how good it looks.
The most significant disadvantage of this flat roofing option is that it is typically only viable at the initial construction of the building. If you were to try and install this system as a roof replacement, you would most likely have to spend a lot of time and money reinforcing the roofing system. Because of its extreme weight, this system should not be installed with occupants in the building as there is a lot of danger involved with the installation process.
Flat Roofing Option 6: Sprayed Polyurethane Foam
Sprayed Polyurethane Foam (SPF) roofing is a probably the best of all the flat roofing options we have discussed here. It has a plethora of benefits associated with it and only a few drawbacks. SPF roofing is a roofing system that is spray applied directly to the existing roof surface; it cannot be a standalone system. Specially formulated chemicals are mixed together in a unique spray gun. This mixing turns the liquid to foam, which then expands to many times its original size.
The advantages of foam are its ease of application, its versatility, its insulating capabilities and its strength. Foam is very easy to apply once you are a trained applicator. It takes some skill and knowledge of the product, but after learning that and practicing it is like riding a bike. It can also adhere to many different surfaces and can be sprayed in different thicknesses to improved roof drainage.
SPF is a great insulator, thanks to the tight bond of the molecules and its seamless application. Finally, SPF roofs are extremely strong, capable of withstanding tornadoes and hurricanes that bring other roofing systems down. If you don’t use spray applied coatings, we believe SPF to be the second best flat roofing material available today.
The major drawback of this system is its cost; it is typically more expensive than most other roofing systems. Another weakness is that it requires a coating overtop of it to resist the UV rays of the sun, and if it doesn’t receive that coating it will deteriorate and begin to fail.
If you are looking to replace your roof or just learning to be prepared in the future, we hope this was a valuable resource for you. If you have any other flat roofing options that you have questions about that we didn’t cover, get in touch with us and we will tell you all we know. If you like what you’ve read, subscribe to our newsletter on the right to receive monthly updates!