4 Types of Flat Roofs: Pros, Cons, and Costs

Are you worried about whether a flat roof fits your budget without sacrificing quality or durability? You don’t want to break the bank, but you also don’t want to unknowingly end up with a low-quality roof.

If you’ve ever had these concerns, you’re not alone, many homeowners wonder which flat roof material provides the best value for their money.

At RoofSmart, we have many years of experience helping homeowners decide which roof is right for them using our SmartMatch Needs Analysis process. We take into consideration your needs, your budget, and your aesthetic preferences to help you find the right roof your your home.

This article will break down the pros, cons, and costs of the 4 different flat roof types so that you can confidently decide which one best matches your needs and budget.

What are the different types of flat roofs?

These are the 4 most common types of materials used on a flat roof:

• Torch Down– This is made of bitumen, which is a mixture of asphalt and rubber. Some versions are smooth on the top, so they require a coating to protect them from UV rays. Some versions have a granule layer on the top (it looks like a big shingle) instead to protect from UV rays. Just like the name suggests, it gets adhered to the roof using a torch gun.
• PVC– This stands for polyvinyl chloride. It is a plastic material that has a lot of plasticizers in it, making it pliable and flexible. There is a layer of fiberglass mesh in the middle. This is the top-tier option for flat roof materials. A heat gun is used to adhere the PVC to the roof.
• TPO– This stands for thermoplastic polyolefin. It is a rubber-based product that has multiple different layers. It is meant to serve as a more affordable alternative to a PVC roof. Just like with PVC, a heat gun is used to adhere PVC to the roof.
• EPDM– Ethylene propylene diene terpolymer is also a rubber-based product made of ethylene and propylene. It can’t be installed in the rain or any other type of bad weather, so summer is the only time you can have it installed. It must be laid out flat and then the adhesive is rolled onto it using a paint roller.

Comparing Flat Roof Types: Lifespan, Cost, and Durability

Torch Down: Affordable and practical

Pros: This is the cheapest option available for a flat roof. At $8-$9 per square foot, you simply can’t beat the price. When installed properly, it holds up well in the rain. And you can choose between two different looks (smooth or granulated).

Cons: It only lasts about 10-12 years. It will be even less than that if there is standing water. It is also prone to leaking when penetrated.

PVC: Waterproof, flexible, but expensive

Pros: PVC is completely waterproof (when you do not drill any holes in it). It will not leak or wear down with moisture, even if a pool of water builds up on it. It is also very flexible and easy to work with, so you can mold it into any shape you need. When installed properly, it will last 30 to 40 years.

Cons: It is the most expensive option for a flat roof (because it’s great material!). It costs upwards of $12 per square foot to install.

TPO: Energy-efficient, but mid-range

Pros: TPO is a more affordable option than PVC it costs about $10 per square foot. When you choose the white option, it reflects heat and helps to cool your house down.

Cons: It does not handle standing water very well, so it is significantly less waterproof than PVC. It is also much stiffer than PVC, so it is more difficult to shape it around things (like the base of a chimney). It is very prone to leaking if every single cut edge is not sealed.

The formula for TPO is constantly changing, so there is no way to know for sure how long it lasts. The average installed assembly is usually around 15 to 20 years.

EPDM: Reliable, but finicky to install

Pros: EPDM is a great material because it is waterproof and it lasts 20 to 30 years when installed properly. It is a more affordable option, costing about $9-10 per square foot.

Cons: It only comes in black, so it can make the roof hot. Also, EPDM is very temperature-sensitive, so it can only be installed in specific weather conditions. It can’t be rainy, and it can’t be too cold or too hot.

Comparison Chart

How do I know which roof type is the right fit for me?

In the end, it is up to you to decide which of these roof types best matches your priorities. It’s important to consider:

• Which pros are most important to you
• Which cons you want to avoid the most
• Your budget, and remember that all of these costs are for just the roofing membrane. What about insulation, roof decking, access, etc?
• How long you want your roof to last

If you have a chimney or a lot of vents and other things sticking out of your roof, then PVC is the best material to flex around them easily. If you’re in the Seattle area and looking for the best possible waterproof roof, then PVC is the best choice.

If you want a cheaper alternative to PVC and you have a roofer who is experienced in installing TPO, then TPO is a good choice for you. However, if you’re just looking for cheap alternatives, then Torch Down is the best choice because it is the cheapest.

If you’re looking for a flat roof material that will last for a while, then you should consider PVC or EPDM.

Making a final decision

In the end, choosing the right flat roof for your home depends on balancing your budget, desired lifespan, and specific roofing needs. Torch Down offers affordability but requires more maintenance, while PVC provides long-lasting, worry-free waterproofing at a higher price. TPO and EPDM give you a solid middle ground, each with its own set of benefits and limitations.

Ultimately, it is up to you to decide what your priorities are and which option will work best for you.

After reading this article, you might want more information on how long each flat roof lasts to help you make your decision or to help you decide when you should install your new roof. Check out our article “How Long Does A Flat Roof Last?” to learn more about the lifespan of flat roof types and the factors that impact it.