What Is Modified Bitumen Roof? | How to Install Modified Bitumen Roofing?

 Modified Bitumen Roof

Modified Bitumen Roofing system is the common low-slope roofing system. It is not like asphalt roll roofing, TPO, or EPDM.

Modified Bitumen doesn’t consist of hot asphalt with plastic and rubber additives. Between sheets of polyester or fiberglass, they are layered.

In the mid-1960s in Europe, modified bitumen first appeared in commercial roofing. The conventional roofing system was built-up roofing. It is made of an asphalt layer with a top layer of gravel.

The BUR is very useful, but it has some downsides too like it is heavy, it is expensive to install, it doesn’t work well in extreme temperatures, and it is difficult to repair.

It was successful in resolving the problems with BUR, it is easy to install, and it works properly even in extreme temperatures like cold weather.

By 1975, modified bitumen was being used in the United States. Now it is one of the most reliable roofing systems.

Today in this post, you learn about what is modified bitumen roof is. How to install modified bitumen roofing?

Also Read: Type of Building Materials

What Is Modified Bitumen Roof?

What Is Modified Bitumen Roof

Modified Bitumen Roofing system is the common low-slope roofing system. It is not like asphalt roll roofing, TPO, or EPDM.

Modified Bitumen doesn’t consist of hot asphalt with plastic and rubber additives. Between sheets of polyester or fiberglass, they are layered.

This type of roofing is typically used in Seattle because it gives resistance to tearing. The fiberglass and polyester reinforcement layers help the material to become tear-resistant.

There is everything in the article you want to know about Modified Bitumen Roofing. You come to know about.

What is Modified Bitumen roofing, its history, how to install it, its type, its advantages, and disadvantages? By knowing all of this, you can know what kind of roofing you want to do in your house.

It also gives the waterproof characteristic to the roofing. It also handles foot trafficking well. So it has good advantages over another roofing system which you will read below in the article.

You can take a look at the advantages and disadvantages of the system and compare it to others. Though there are disadvantages to this system, it can be solved by maintenance and precautions.

And the advantages weigh down the disadvantages. It has many advantages, which many house owners prefer. Hope so you get some good out of this article.

The framework of the Modified Bitumen Roofing system is a combination of five-layer roofing components.

The Five Layers Are: insulation Modified Base Sheets or Piles Modified Between Membranes, Adhesive Surfacing

1. Insulation: This layer is used to give R-value or thermal insulation resistance for the temperature stability of the roofing system.

2. Modified Base Sheets or Piles: this layer gives the system the flat surface it has.

3. Modified between membranes: It is a sheet membrane that contains co-polymer reinforced with polyester or fiberglass. This membrane is fabricated in factories.

4. Adhesive: This layer is added for waterproofing. It can be applied on the roof’s surface, either cold or hot.

5. Surfacing: This layer provides protection from UV rays and is used as weather resistance.

Also Read: What Are Traps in Plumbing? | 14 Type of Trap in Plumbing

What Are the Benefits of Modified Bitumen Roofing?

What Are the Benefits of Modified Bitumen Roofing

There are various benefits of modified Bitumen roofing that are as follows:

  1. Energy Efficient: Most of the modified roofing systems provide resistance to UV rays. And because of this, the houses are able to maintain the inner temperature well. And It does not affect the HVAC system much. So it saves on energy bills.
  2. Tear-resistance: Modified bitumen gives fantastic durability and strength to the roof. It provides resistance from the tearing of debris, weathering, and consistent foot traffic.
  3. Waterproof: It also protects the house from moisture. If it is installed properly, it gives waterproofing protection to the roof. And because of its multiple layers, it is more efficient in waterproofing.
  4. Flexible: It contracts and expands easily with changing weather conditions. It is flexible in its working method and doesn’t lose its efficiency.
  5. Easy to Install, Repair and Maintain: It is very easy to install, so it helps the staff to install it. It is easy to repair if there are any leaks or cracks. It can be maintained well.

Modified Bitumen Membrane Roofing Types:

Modified Bitumen Membrane Roofing Types

modified bituminous membrane roofing is categorized into two types-APP, and SBS

1. App Roofing System Membranes:

App Roofing System Membranes

Atactic polypropylene (APP) is commonly known as plastic asphalt. APP membrane contains a plasticized polymer that shows elasticity properties when going through high temperatures.

It protects the house from UV rays and also gives the structure of the roof a cool look. It is preferred by people who want to protect their houses from extreme conditions.

Also Read: What Is a Gambrel Roof Design? | Gambrel Roof Angles

2. Sbs Roofing System Membrane:

Sbs Roofing System Membrane

Styrene-butadiene-styrene (SBS) is referred to as an elastic rubberized asphalt membrane, it contains asphalt with polymerized rubber which gives it flexibility and elasticity property.

If your roof expands and contracts in extreme climate conditions, it is one of the best types to choose from. SBS roofing installation also protects the house from high winds.

Application Methods for Modified Bitumen Roof

Application Methods for Modified Bitumen Roof

There are different types of Modified Bitumen roofing systems to install. Below we are going to read about the two different types of installation of Modified Bitumen roofing.

Two types of Bitumen roofing installation are: The torch-Down installation method and a peel and stick installation method.

Tools Used in the Installation of Modified Bitumen Roofing

  • Measuring tape
  • Hammer
  • Chalkline
  • Large propane torch
  • Utility knife with a hook blade
  • Spark igniter

Materials used in the installation of Modified Bitumen Roofing

  • Roof insulation
  • Heavy roofing felt
  • Modified-bitumen roofing
  • Drip-edge and other flashings
  • Spray primer
  • Cap’s nails
  • Roofing nails
  • Roofing cement

So here is a step-by-step guide to building up a modified bitumen roof.

How to Install Modified Bitumen Roofing?

How to Install Modified Bitumen Roofing

The process of the installation of the Torch Down Bitumen Roofing is as follows:

  • This process is dangerous for those who want to do it alone because it involves working with petroleum products and felting. Because of the work required to be done using fire, it must be done by professional roofing. So here is a step-by-step guide to installing torch-down modified bitumen roofing:
  • First, you have to check the roof properly and eliminate all the debris in the area for better results.
  • Overtop your decking, insulation, or old roof and install heavy roofing. Secure the felt properly by using cap nails to the rows along the top and bottom and the sheets. And repeat that for the middle rows.
  • Drip edge flashing should be installed in this step, and then the primer should be applied so the roofing will adhere to it.
  • In this step, you must roll out the roofing sheet, leaving an overhang for a few inches on all sides of the roof. Then again, allowing a few inches of overhang on the roof cut the roofing.
  • Adjust the roofing so it can overhang the flashing by a half-inch, and check the roofing; it should be perfectly flat. Otherwise, the installation won’t work properly. Then carefully roll back the roofing back up tightly halfway.
  • For this step, you must wear heavy gloves and long sleeves for protection from a propane torch.
  • Turn on the propane torch and spread the tip of the flame along the crease between the roofing roll and the roofing felt. Gently roll the roofing forward with your foot when you see bubbles forming during the process of installation.
  • The next sheet should be aligned in a way so that it can cover the edge of the sheet of modified bitumen roofing by a few inches. And after that, repeat the process again.
  • Press the seam between the two sheets using your foot and gloved hand. Then ensure that it is tightly sealed. A bit of melted bitumen should be oozed out along the joint.
  • Repeat this process for the remaining portion of your flat foot.

How to Install a Peel-And-Stick Modified Bitumen Roofing?

How to Install a Peel-And-Stick Modified Bitumen Roofing

It is a built-up, modified bitumen roof that is a type for do-it-yourself. As it does not involve working with fire and fumes, you can do it by yourself. So here are the steps to install peel-and-stick modified bitumen roofing.

First, the five-step is exactly similar to the torch-down modified bitumen roofing installation, which is written above. After following those steps, then you can start working on the steps which are written below.

First, you have to remove the adhesive film and carefully roll the roofing back into the original place. Before adhering the material to the flat roof, ensure it is smooth out.

Leaving an overlap of at least six inches, repeat this process for the entire area of the rooftop.

Roll over the entire area of your roof by using a weighted roller. Pay special attention to the overlap. Otherwise, it will not be done properly.

Seal the edges of the Modified Bitumen Roofing with the help of roofing cement. Then roll all the sheets together to seal them together.

Modified Bitumen Roof Problems

Modified Bitumen Roof Problems

The problems with the Modified Bitumen roofing system are that it has low life expectancy than other roofing systems. It can work well for 10-20 years approximately. Then you have to change the system or upgrade it.

It is one of the main reasons people choose another roofing system, as they want their roof to last for a long time.

It is not easy to install if to choose torch-down modified bitumen roofing. As it involves working with fire and heat.

In the installation process, a blow torch is used to extreme heat to install sheets on top of the roof. If you come in contact with harmful fumes, it can be dangerous.

It also has a problem with the drainage system, as it is a flat roof, it doesn’t have to the drainage system. The water gets collected on the roof’s surface, and if the water is not removed quickly, it can be absorbed by the roof. It can create mold and mildew on the roof.

It can be coated faster than other types of flat roofs. The modified bitumen roof system gives off a strong unpleasant odor after the installation process is complete.

How Long Does a Modified Bitumen Last?

How Long Does a Modified Bitumen Last

Modified Bitumen Roof Systems can last for 10-20 years. Which is less time in comparison to another roofing system. The amount of time Modified  Bitumen roofing lasts depends on many things.

Like the materials used, if the system is installed properly or not, if it is checked frequently and if there is any issue repair should be done properly and maintained well.

Built Up Roof Vs Modified Bitumen

Built-up and modified bitumen roof systems are usually designed for low slope or flat roof structures. While both can withstand harsh weather conditions and harmful UV rays, the two are different in terms of design, application, advantages, and life expectancy. Read on to learn more about these roofing systems and evaluate the best option for your commercial building.

Modified Bitumen Roofing Installation

A modified bitumen roofing system can be installed using the torch method, asphalts, or cold adhesives. A standard SBS-modified bitumen roof system is a two-ply system applied in rolls overlapping the edge of the previous roll.

Advantages of a Modified Bitumen Roofing

Advantages of a Modified Bitumen Roofing

Here are some advantages that the installation of the Modified Bitumen Roof System provides:

  1. Seamless connections: There are three ways to install modified bitumen roofing– self-adhesive, cold adhesive, and heat. These are the reasons why the sheets are seamlessly connected properly. It has efficient adhesive nature, which makes the connection between the sheets of the roof durable.
  2. Tear resistance: It is made by a combination of fiberglass and polyester reinforcement. Which made the sheets tear-resistant and durable. It also handles foot traffic well. Because of this, it doesn’t have to be repaired quite frequently.
  3. Weather resistance: The modified bitumen roofing system is a composition of five-layer to withstand extreme conditions in all climates. It doesn’t allow much heat to pass through the house’s roof. It is also good for cold weather. And it also works efficiently in other environmental conditions.
  4. UV rays and heat resistance: This system is well known for its heat-reflective property. Because of the heat reflection, it protects the house from harmful UV rays, which is not only bad for the house but also for the people living in it. This reduces the house’s energy bill. So it is a money-saving scheme in the long term.
  5. Leak resistance: It is a flat roofing system that is leakproof. The materials used in this system help the area to be leak-proof for a long time. Its coherent nature made it easy to do that.
  6. Style options: The materials used in this system have several varieties, which help you to customize it according to your taste. The color of granules in the cap sheet can choose according to the color of the shingles used in the roofing of your house. You can choose the outside look it gives because of the different types of materials used in this.
  7. Easy to install and repair: It is easy to install. It can be done by yourself. You can easily do the peel-and-stick installation modified bitumen roofing method. There are rolled sheets 3 feet wide and up to 36 feet long, which can be rolled easily on the top of the base sheet of the roof. The repair can be done easily and quickly by using bitumen patches on the cracked surface.
  8. Environment friendly: The sheets used in this can be recycled. You can reuse the sheets by dumping them outside. It not only saves you money but it helps in reducing the waste of material, which is good for the environment. It reduces the carbon footprint.

Disadvantages of a Modified Bitumen Roof

Disadvantages of a Modified Bitumen Roof

Here are some disadvantages of the Modified Bitumen Roof system

  1. Lifespan: The average life expectancy of Modified Bitumen Roofing is 10-20 years. It is quite a good time for the roof, but if you compare it with other systems, it is very low time. Other types of flat roof systems sustain for more years than this. So if you want your house to be protected long-term, there are better options for a roofing system than this.
  2. Water resistance: The absence of a drainage system on the flat roofing system makes it quite difficult for water to run down the roof. Water gets collected on the surface of the roof, which spreads the moisture in the house. Which can turn into mold or mildew at any time.
    Modified bitumen in comparison to other flat roof types like TP or PVC, wears down faster. It can damage the roof if it doesn’t get repaired immediately.
  3. Torch fumes: During the modified Bitumen roofing installation process blow torch is used to extreme heat to install the sheets on the roof. Those fumes can be harmful if it comes in contact with people. It also causes some health issues. And it has a good effect on the environment.
  4. Foul odor: It gives a strong odor after the completion of the process of installing the Modified Bitumen System. The effect of the odor depends on the area covered in the installation. It is better to relocate temporarily during the process of installation of the roofing system is going on. It will help you to avoid the foul smell of the roofing system.

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Frequently Asked Questions

What Is Modified Bitumen Roof?

Modified bitumen (MB) roofing is a cousin of asphalt-based, built-up roofs (BUR). The modified Bitumen Roofing system is a combination of five-layer roofing. This layer includes Insulation, Modified Base Sheets or Piles, Modified between membranes, Adhesive, and Surfacing.

How Long Does a Mod Bit Roof Last?

Mod bit roofing system can last for 10-20 years. Which is less time in comparison to another roofing system. The amount of time Modified  Bitumen roofing lasts depends on many things.

What Is Modified Bitumen Roofing Material?

Asphalt modified bitumen is made by combining the polymer with fiberglass or polyester reinforcement. This type of roof is made of an impermeable roof membrane. This type of roofing gives the roof better weatherproofing protection and durability than traditional asphalt built-up roofing (BUR).

Can You Bitumen Roof Repair?

When the modified bitumen coating is damaged, it can be repaired and controlled. The method of patching it is common.

Modified Bitumen Roof Replacement Cost

If you want to install a new bitumen roof over an existing roof, the Modified Bitumen Roof Replacement Cost can be $4 to $8 per square foot.

Modified Bitumen Roof Cost

The total Average Cost of a Modified Bitumen Roof from Basic to Best can range from 4.00 to $ 5.55 per square foot. The actual cost of bitumen roofing depends on factors such as the quality of the materials used, your location, and the complexity of the installation.

Modified Bitumen Roof

Modified bitumen is thought of as the evolutionary cousin of the built-up roofing systems (BUR) that have been used on low-slope roofs for more than 100 years. It is made of asphalt combined with polymerized rubber or plastic, then reinforced with fiberglass to create a rugged-yet-flexible waterproof membrane.

What Is a Mod Bit Roof?

Mod-bit roofing(MB) is a shorter way to say modified-bitumen roofing. MB roofing systems are a durable, weather-resistant type of low-slope roof. Mod-bit materials are sold in rolls, and their seams are sealed using heat (the common open flame torch), hot- or cold-applied, or self-adhering.

What Is Bitumen Roofing?

Bitumen is a type of asphalt that can be applied in both hot and cold temperatures. Substances are added to standard roofing asphalt and fiberglass or polyester is used to increase durability and strength. The systems can be installed using a common torch method, asphalts, or cold adhesives.

Modified Bitumen Roofing Installation

A modified bitumen roofing system can be installed using the torch method, asphalts, or cold adhesives. A standard SBS-modified bitumen roof system is a two-ply system applied in rolls overlapping the edge of the previous roll.

Built Up Roof Vs Modified Bitumen

Built-up and modified bitumen roof systems are usually designed for low slope or flat roof structures. While both can withstand harsh weather conditions and harmful UV rays, the two are different in terms of design, application, advantages, and life expectancy. Read on to learn more about these roofing systems and evaluate the best option for your commercial building.

Modified Bitumen Roof Life Expectancy

The roofing material is asphalt-based, flexible, and features a mineral top coating. Modified bitumen roofs last upward of 20 years or longer with proper maintenance. This flat roofing material is recognized for its strength and durability.

Modified Bitumen Roof Problems

  • Improper roof slope causing water pooling and degradation of materials.
  • Seam separation/defects from improper application of adhesives.
  • Insulation improperly fastened or installed.
  • Blisters develop when moisture penetrates the material.
  • Incorrectly installed flashing.

Modified Bitumen Membrane

Modified bitumen is thought of as the evolutionary cousin of the built-up roofing systems (BUR) that have been used on low-slope roofs for more than 100 years.

Modified Bitumen Roof Cost Per Square Foot

Once installed, this material reflects heat well. It’s also quite affordable, usually costing between $4 and $8 per square foot. Its lifespan is about 10-15 years.

Granulated Modified Bitumen

A granulated modified roof is a form of asphalt that’s rolled onto a roof in sheets. Torch down and cold applied with adhesive is the common installation method. “Modified” is when extra materials are installed over the asphalt sheets. The purpose of the modification is to make the roof watertight.

Gaf Modified Bitumen

GAF has added two modified bitumen membranes to its Ruberoid family of roofing products. EnergyCap MOP FR is a fire-retardant membrane with an elastomeric coating; a polyester mat core offers split and tear resistance.

How to Install Modified Bitumen Roofing?

  1. Ensure your flat roof is entirely clear of debris.
  2. Install heavy roofing felt with overtopping your decking, old roof, or insulation.
  3. Install drip edge flashing, and apply a primer so the roofing will adhere to it.

SBS Modified Bitumen

SBS-modified bitumen roofing is a material made out of asphalt and synthetic rubber, making it an exceptionally flexible material for flat roofs. Thanks to its rubber composition, the material is less prone to cracking and sustaining damage from elements like ice and sun.

What Is a Modified Bitumen Roof?

Modified bitumen is used on low slope or flat roofs, either commercial or residential, but more often on residential buildings such as homes, apartments, etc. You will also find modified bitumen on low-slope sections of generally steep-sloped roofs.

Types of Modified Bitumen Roofing

There are two main types of modified bitumen sheets: SBS and APP. APP. This stands for Atactic Polypropylene and is a thermoplastic that is placed in the asphalt to reflect UV rays while protecting against colder temperatures. SBS.

What Is Sbs Roofing System?

SBS, also known as styrene-butadiene-styrene, refers to the type of polymers that are added to the asphalt. SBS is a thermoplastic elastomer that’s resistant to harsh abrasions, making it an extremely long-lasting membrane when blended with bitumen, also known as asphalt.

Modified Bitumen Vs Roll Roofing

TPO roll roofing is generally less expensive to purchase and install but does not have the long-lasting appearance that modified bitumen roofing has. Modified bitumen systems are excellent at keeping moisture out of roofs but require added drainage systems to continue working correctly.

Polymer Modified Bitumen

Polymer-modified bitumen (PMB) is bitumen (asphalt) combined with one or more polymer materials. This modification is done with the aim of enhancing the mechanical properties of the bitumen material.

Peel and Stick Modified Bitumen

Peel & Seal roll roofing will not tear, crack or dry out over time. It is designed specifically to reflect heat and resist water and exposure to other elements without any additional coverage needed.

TPO Vs Modified Bitumen

TPO is an acronym for thermoplastic polyolefin. It’s been around since the ‘90s, and it has recently skyrocketed in popularity. TPO is a single-ply surface. That means it takes much less time and effort to install it on top of a roof. Modified bitumen roofing is a classic material for commercial construction. It was pioneered in the ‘70s and represented a major upgrade from traditional asphalt roofs. Modified bitumen became widely used largely because it is so affordable.

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