If you’re in the market for a new flat roof installation or replacement, there are four different types to choose from. Flat roofs provide many benefits to the everyday homeowner, such as high affordability, extra usable space, more versatile interior design opportunities and better accessibility when cleaning gutters, making repairs or installing things like satellite dishes or solar panels.
Flat roofs are typically paired with a 10- to 20-year warranty but can last up to 25 years or longer if properly installed and maintained.
Built-Up Roof (BUR)
A built-up roof provides the traditional form of hot-tar-gravel and is constructed from three or more piles of waterproof material alternated with hot tar and ballasted by a smooth layer of river stone. In the past, BURs consisted of simple tar paper, however, these types of roofs are shifting with the use more complex materials such as fiberglass membranes.
Pros of a BUR: When you choose a BUR, you get excellent protection from fires, as well as an attractive place for windows and decks that overlook the roof. It’s also one of the most affordable options of the four flat roof types.
Cons of a BUR: BUR materials are severely heavy meaning joists will need to be strengthened in some cases. It’s also a messy and smelly installation process, meaning you probably won’t be able to occupy your home while it’s being laid. Additionally, gravel can clog gutters and leak sources can be hard to pinpoint.
Modified bitumen roofs are a single-ply rolled roof that acts as an ice-and-water protectant, and is saturated with a mineral-based wear surface to provide extra protection. Through a torch-down approach, the adhesive is heated as the material is unrolled. Peel and stick systems have also been introduced which makes the process simpler and safer.
Pros of Modified Bitumen: Modified bitumen has a light colored mineral surface which is great for reflecting heat which will slash your energy bills. The peel-and-stick option is also perfect for DIYers who want to work on their roof themselves. In terms of price, it’s not the most expensive, but also not the cheapest, making it a good middle-ground option.
Cons of Modified Bitumen: If you choose the torch-down application, you’re opening up your home to fire risks, and you won’t be able to occupy the building during installation. It also isn’t as resistant to scuffing or tearing as rubber-membrane roof materials.
A rubber membrane roof consists of ethylene propylene diene monomer (EPDM) and is durable enough to resist sun damage. EPDM can be mechanically anchored to your structure with special fasteners, stone or glued.
Pros of Rubber Membrane Roofs: These types of flat roofs are perhaps the most homeowner-friendly to install and maintain. EPDM material is highly resistant to scuffing and tearing, while also remaining relatively lightweight. Leaks are also very easy to repair.
Cons of Rubber Membrane Roofs: With rubber membrane, the black material that comes standard is capable of absorbing heat, while lighter-colored coats (which are more expensive) are better for warmer-temperate climates. While this type of flat roof is popular, it costs more than both BUR and modified bitumen.
Spray foam roofs are ideal for those homeowners that want a cost-effective and long term solution to their roofing problems. You’ll see huge energy savings when you choose to protect your roof with spray foam.
Pros of Spray Foam: Spray foam features advanced tensile strength and durability that’s highly comparable to that offered by more traditional roofing systems. Additionally, it’s completely seamless, waterproof and a fully adhered to the existing roof substrate.
Cons of Spray Foam: Spray home cannot be applied by the everyday DIYer and has to be applied by a professional. This type of roof has rigorous specifications and requires steady expert hands for effective application.
Best of Luck with Your Flat Roof Installation!
Now that you know the four different types of flat roofs to choose from, you can make an informed decision on your upcoming roof installation or replacement project. With the many benefits that flat roofs provide, you’ll add functionality, beauty and value to your home!