Rolled Roofing vs. Modified Bitumen: Which to Choose?

Rolled Roofing vs. Modified Bitumen: Which to Choose?

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If you are constructing a new home or building, the roof is one of the most important parts. After all, it’s what keeps the wind and rain out. That said, there are actually many different types of roofing materials out there, and they’re not all built the same.

Right now, we want to take a look at two very popular roofing options, rolled roofing, and modified bitumen. They may share some similarities, but in the grand scheme of things are quite different, and these differences are exactly what we’re here to determine today.

What Is Rolled Roofing?

First, we have what is known as rolled roofing. As you can assume, this consists of using a large roll of a very special material to cover the exterior of a roof. The material most often used for this purpose is oil-based asphalt.

There are other materials that may be used, although this is the most common. Sometimes, rubber or rubber mixed with slate dust is used, or even an ethylene-propylene-based rubber. That said, for the purposes of today’s article, we’ll be focusing on the asphalt version.

This is designed to be a quick and relatively cost-effective way of protecting a roof in place of using individual shingles.

One of the reasons why this method is so popular is due to its quickness and cost-effectiveness. You only need to install a single layer, which means that work can be done in just a few hours.

This type of roofing option is somewhat durable, as it can last anywhere between 5 and 20 years. This does however depend on weather conditions, installation quality, and more. Perhaps the biggest benefit besides being quick is how cheap it is. This is why so many people choose rolled roofing, as it’s perhaps one of the cheapest options out there.

What Is Modified Bitumen?

We then have modified bitumen roofs, which are considered some of the best in the world. This method consists of using a great many layers of roofing materials, such as those used in rolled roofing. This is designed to cover up the exterior surface of any roof.

The big difference is that all of the individual rolls of material are placed in between layers of felt, and these layers of felt are coated with modified bitumen. These are known as polymer layers or cap sheets. Modified bitumen is a fantastic material because it helps to reinforce and protect your roof, much better than both rolled roofing and individual shingles.

Modified bitumen itself is a material that consists of boiling hot asphalt, rubber, and plastic. This type of roof can be very difficult to install and definitely requires professional installation because it consists of multiple layers, it’s relatively dangerous to do, and difficult as well. It’s also very time-consuming.

That said, because it is so time-consuming and many layers are used, and due to the quality of the materials, this type of roof is also very durable. These roofs can last for up to 30 years, or even longer. Simply put, you get what you pay for, and although this type of roof features a very high cost, it’s also considered one of the best out there.

Rolled Roofing vs. Modified Bitumen: What Are the Differences?

Now that we know what both rolled roofing and modified bitumen roofs are, let’s take a closer look at what sets the two apart.

Materials Used

One of the biggest differences here has to do with the materials used, which leads to most of the other differences. With rolled roofing, you generally just have a roll of asphalt and adhesive, which forms one single layer.

However, with modified bitumen roofs, you have several layers, which could also involve rolled roofing asphalt layers, as well as felt, modified bitumen, and more.

Ease of Installation

With rolled roofing, the installation process is quite quick and easy. It should take a crew only a single day to install this type of roof. Since there is only a single layer, there is not a great deal of work to be done.

Modified bitumen roofs on the other hand require larger crews to install, more expertise, and much more time. There are many layers present, and the process is more difficult.


Something many people may not think about is that rolled roofing options are very lightweight and are ideal for small structures that cannot support a lot of weight.

On the other hand, bitumen roofing ends up being very heavy and is therefore only ideal for structures that are extremely structurally sound and stable. Because of this, this type of roofing is usually only applied to larger buildings.

Overall Durability

When it comes down to it, modified bitumen roofing is just much more durable. It holds down for longer, it resists weather better, and it’s much more impact-resistant too.

Rolled roofing sheets are much more susceptible to tearing, damage from weather, and just coming loose. Rolled roofing can be somewhat durable if installed properly, but it just doesn’t stand up to modified bitumen roofing.


In general, you can expect rolled roofing to last for anywhere from 5 to 20 years, with modified bitumen roofs lasting anywhere from 20 to 30 years.

This does of course depend on the general climate and weather conditions, as well as the quality of the installation.

General Application

Rolled roofing options may be used for regular houses as well as for larger commercial properties, whereas modified bitumen roofing is usually reserved for large buildings, generally for flat roofs.


Rolled roofing may cost anywhere between $30 and $100 per roofing square, which is equal to 100 square feet. Modified bitumen roofing, on the other hand, may cost you anywhere between $250 and $400 per roofing square.

Rolled Roofing vs. Modified Bitumen: Which One to Use?

What it really comes down to here is cost versus quality. If you need a type of roofing material that is extremely cost-effective and won’t break the bank, then rolled roofing is a fine option to consider. If properly installed it can last for up to two decades, all without costing you a fortune.

Furthermore, it’s a great option if you have a smaller structure that can’t support a lot of weight. If it’s a small house that can only support a limited amount of weight, then modified bitumen probably isn’t an option at all.

However, for larger structures, modified bitumen is definitely a good option. If you don’t mind paying the extra cost for it, it is one of the best investments you could possibly make on this front. It’s much more durable than rolled roofing, and it lasts much longer.


Both of these roofing options are perfectly fine in their own rights, but they are of course quite different. Therefore, we recommend looking into this issue in more detail before making a decision.