Pros and Cons of a Modified Bitumen Roof

Modified Bitumen Roof Replacements in Florida
April 23, 2024

If you’re in the market for a flat roof replacement, then a modified bitumen roof is certainly worth considering. After all, mod bit roofs are some of the most common flat roofs in Florida! But are these roofs really worth the investment in your property? And what do you need to know about the downsides of modified bitumen roofing?

PITCH Roofing is here to answer all of these questions and more. Our team of roofers has decades of local roofing experience, and today we’re using that to explain the good and the bad about modified bitumen. But before we get too deep into the pros and cons, let’s talk about the basics of modified bitumen roofing that you’ll want to know.

Modified Bitumen Roofs Explained

Modified Bitumen Roofs Explained

Modified bitumen is unique thanks to its asphalt-based composition. Whereas other flat roofing options are based primarily on rubber, mod bit’s asphalt can be modified to provide different types of protection to your structure.

For example, mod bit usually comes in two types: SBS and APP. SBS (styrene-butadiene-styrene) mod bit uses a rubberized polymer to make the asphalt more elastic and flexible, which helps protect against two of Florida’s largest issues: heavy rains and high winds. APP (atactic polypropylene) mod bit, on the other hand, uses a plasticized polymer that will only expand under high temperatures. This helps it withstand Florida’s year-round UV exposure.

Regardless of what type of modified bitumen roof you get, though, the good and the bad of mod bit look largely the same. And if you need a flat roof replacement, knowing what to expect from your new roof is crucial.

Modified Bitumen Roofing – Video

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Pros and Cons of a Modified Bitumen Roof

Modified bitumen roofing came about as the successor to built-up roofing (BUR). And by improving on this old-school roofing material, mod bit has increased its strength and removed many key weaknesses of BUR.
Now, let’s talk about what this new and improved flat roofing material can do for you!

Pro: Low Flat Roof Replacement Costs

Part of what makes mod bit roofing so popular is its affordable price point. Pricing factors can cause exact numbers to vary, but generally, a modified bitumen roof costs four to eight dollars per square foot.

The average size for a roof is generally considered to be around 1,700 square feet. So on an “average” roof, a modified bitumen roof replacement would cost between $6,800 and $13,600. This low cost is thanks to how cost-effective mod bit is to manufacture and how easy it is to install.

As a result, modified bitumen is one of the most affordable flat roofing materials. So if budget is a primary concern for your flat roof replacement, mod bit could be just what you need.

Con: Unremarkable Life Expectancy

Lifespan, like cost, is usually one of the biggest factors when considering a flat roof replacement. And while modified bitumen comes at a great price point, it’s important to consider how long your new roof will last.

A modified bitumen roof will last for a fair amount of time, but there are undeniably other options that last longer. Specifically, modified bitumen roofs average 15-20 years of life. A TPO flat roof, on the other hand, could last 20-25 years.

This is why it’s not enough to just look at price or any one factor. By knowing both the good and the bad, you can better determine the total value of your new roofing system.

Pro: Thick, Durable Composition

Single-ply roofing membranes are popular for their flexibility and water resistance. But modified bitumen isn’t a single-ply roofing material. Instead, it’s usually made of two or three layers of asphalt, fiberglass, and either plastic or rubber polymers.

For example, your average single-ply roofing membrane is around 60 mils thick. A two-ply modified bitumen roof, however, is closer to 240 mils thick. This offers increased protection against storm debris and other sources of puncture damage that could easily cause a leak in a thin roofing system.

Con: Attracts Heat and UV Rays

In most cases, modified bitumen roofs are black. As a result, they tend to attract more heat than other flat roofing materials. In fact, even when they come in white, mod bit roofs don’t reflect much UV light and end up with similar issues.

This can create trouble by attracting too much heat to your roof. When this happens, your energy bill can increase substantially, especially if your previous roofing material wasn’t black.

There is one piece of good news, though. Most manufacturers offer cap sheets that greatly improve how much UV light your roof can reflect. If you’re worried about your energy bill, ask your roofer about an additional cap sheet when you get your free roofing estimate!

Pro: Great for Foot Traffic

Modified bitumen roofs are great for both homes and commercial structures. But mod bit does have a particular advantage with commercial applications since it can help protect high-traffic roofs.

Thanks to its durable asphalt composition and multiple layers, modified bitumen works for areas that see a lot of foot traffic. That said, you should not install modified bitumen for a patio or other area that’s intended to see a lot of use every day. Rather, mod bit works for areas that see a lot of incidental foot traffic, such as space connecting two parts of a building or an incidental, unofficial deck for employees.

Get Your Free Modified Bitumen Roofing Estimate

Get Your Free Modified Bitumen Roofing Estimate

With all of this great information about modified bitumen roof replacements, we hope that we’ve answered all of your questions about mod bit. But if we haven’t, that doesn’t mean we can’t. Be sure to bring all of your questions to your appointment for a free roofing estimate!

Getting a free, no-obligation roof replacement estimate is easy. Simply call us at 727-607-4280 or reach out to us online. Our experienced roofers are committed to total transparency while answering all of your questions, and they’ll be happy to tell you everything they know about your flat roofing options!

PITCH Roofing is a trusted local roofing partner in Florida. Reach out to us today and experience the commitment to honesty and professionalism that separates us from other Florida roofers!

Last Updated:June 19, 2024