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TPO vs. SBS Roofing: Which Material Is Best for Your Roof?

Learn the key differences between TPO and SBS roofing and decide which of the two is best for your flat-roof. Discover the pros and cons of each in our comprehensive comparison guide.

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When it comes to commercial roofing options, TPO and SBS are two of the most popular choices. While both TPO (Thermoplastic Olefin) and SBS (Styrene-Butadiene-Styrene) are flat-roofing systems, they have their unique properties which lend them to be used in different applications. 

In this article, we will compare TPO and SBS while discussing the pros and cons of each. 

Whether you are a building owner, property manager, or roofing contractor, understanding the differences between TPO and SBS roofing can help you make an informed decision about which type of roofing system is right for your needs.

SBS Roofing – All You Need To Know

Let’s take a look at some of the SBS roofing system details, including cost, installation and pros and cons. 

What Does SBS Mean In Roofing?

The SBS in SBS roofing stands for Styrene-Butadiene-Styrene. This synthetic rubber is combined with asphalt to create the roofing material we know as SBS-Modified Bitumen, a highly flexible and abrasion resistant flat-roofing membrane. 

There is another kind of modified bitumen roofing known as APP-modified Bitumen. Let’s differentiate the two below:

What Is The Difference Between APP And SBS Roofing?

The difference is that SBS-Modified Bitumen is made by mixing asphalt with synthetic rubber (Styrene-Butadiene-Styrene), while APP-modified Bitumen is made by mixing asphalt with plastic (atactic polypropylene). Essentially, SBS-modified bitumen is an ‘elastic asphalt’ while APP-modified bitumen is a ‘plastic asphalt’.

Both systems offer better flexibility than traditional Built-Up-Roofing systems, but SBS is the more flexible membrane of the two. 

CRITERIA SBS APP
Bitumen Modifier Type Synthetic rubber Plastic
Thickness (Recommended) 4mm 4mm
Low Temperature Flexibility -22°F to -5°F 14°F to 32°F
Elongation with full recovery >1000% 5-10%
Serviceability range -20°F to 270°F 15°F to 300°F
Weight  4kg/m2 4kg/m2
Material Non-woven polyester mat Non-woven polyester mat
Cost High Low

How Much Does SBS Roofing Cost?

The cost of SBS roofing can vary depending on a variety of factors such as the size and complexity of the roofing project, the location, and the specific SBS roofing membrane you select. Additionally, contractor charges, permits, and other overhead expenses may also impact the total cost.

As a rough estimate, the cost of SBS roofing can range from $4 to $7 per square foot or a total of between $6,000 and $10,000. Keep in mind, however, that this is just a general estimate and the actual price you pay for SBS roofing can vary greatly. 

For an accurate estimate, you’ll need to get in touch with a local SBS roofing contractor. 

Speaking of contractors, let’s take a look at how they bring your SBS roof dream to reality.

SBS Roofing Installation Process

Roof Preparation: Before any membrane laying begins, the roof surface is prepared by removing any existing roofing material and debris. Once the surface is clean and dry, work can begin.

Priming: The contractor then applies a primer to the roof surface to help the SBS membrane adhere properly to the roof deck. The primer may be solvent-based, water-based, or oil based, depending on the sub-roof material and the specific SBS roofing system being used. For some applications, it may be necessary to install SBS roofing underlayment prior to laying the membranes.

Membrane Installation: The SBS membrane is then rolled out over the roof surface and cut to fit the dimensions of the roof. Thereafter, the membrane is attached to the roof using hot asphalt, cold adhesive, or a self-adhering method. The seams between the membrane sheets are then sealed with heat, adhesive, or by applying pressure using rollers.

Flashing Installation: Flashing, which is a material used to seal the edges and seams of the roof, is then installed around roof penetrations, such as vents and chimneys, to ensure a watertight seal. Any cuts made to the membrane to accommodate the penetrations are sealed using roof tar. 

Protection Layer: A layer of protection material, such as gravel or granules, is then added to the top of the SBS membrane to protect it from UV rays and other weathering elements.

Termination: Where applicable, the ends of the membranes are stuck to the edges of the roof using metal termination bars. These bars have holes into which neoprene screws are driven. This ensures the ends remain fastened to the roof. 

How Long Does SBS Roofing Last?

In general, SBS roofing systems can last anywhere from 15 to 25 years. However, the exact lifespan of your SBS roofing system can vary depending on several factors, such as:

  • The quality of the materials used
  • Expertise of your contractor
  • The local climate
  • Maintenance of the roof.

Regular maintenance, cleaning, and timely repairs, can help to extend the lifespan of your SBS roof. Additionally, some SBS roofing manufacturers offer warranties on their product, which can provide additional peace of mind.

Advantages Of SBS Roofing System

  1. High Durability: 2-ply or 3-ply SBS roofing systems are much thicker and therefore much stronger than single-ply flat roofing systems. Single ply membranes range from 40-80 mm thickness while SBS modified systems range from 220 mm to 300 mm thickness. The extra thickness enables SS roofing to withstand heavy foot traffic and sharp objects. 
  1. Flexibility: The presence of synthetic elastomer in the SBS membrane enables it to be very flexible. This property makes it ideal for extreme temperatures since it can expand and contract with the changing temperatures without cracking.
  1. Waterproof: As long as the seams are sealed properly, your SBS roof will not allow water to pass through.
  1. Option for easy installation: SBS roofing comes in a variety of forms including self-adhering mats which you just need to peel and stick onto your roof.

Disadvantages Of SBS Roofing System

  1. Difficult Installation – Some SBS roofing systems require a torch-down application whereby the membrane is heated with a flame to make it adhere to the roof. This method is not suitable for DIY homeowners.
  2. Fire Hazard: The torch-down method is not only difficult but is also a fire hazard at the construction site. If you elect to use this method, make sure to hire a reputable ad licenced roofing contractor. 
  3. Relatively Higher Cost: SBS roofing can be more expensive than other roofing materials such as TPO, making it less attractive for those on a tight budget.

SBS Roofing Frequently Asked Questions

What is SBS roofing made of?

SBS roofing material is made up of a mixture of asphalt and a synthetic rubber known as Styrene-Butadiene-Styrene. This synthetic elastomer is what gives SBS roofing its flexibility. 

TPO Roofing – All You Need To Know

What Is A TPO Roofing System?

TPO roofing is a single-ply flat-roofing system that is made up of a single layer of synthetics and reinforced scrim. Due to their characteristic white surface reflective finish, TPO roofs are also known as white roofs.

TPO roofing membranes are commonly available in two standard thicknesses, 0.045 AND 0.06 inches. As opposed to SBS-modified bitumen, TPO systems require more experienced roofing contractors, and more specialized equipment. 

TPO roofing is quite popular in the U.S. and accounts for over 40% of installed commercial roofing membranes.

What Is TPO Roofing Made Of?

TPO stands for Thermoplastic Polyolefin. It is a synthetic elastomer (rubber) that is made primarily from recycled rubber.

The actual roofing membranes consist of two sheets with a scrim in between them. This scrim is typically made of polyester or fiberglass and acts as a reinforcer, enhancing the strength and durability of the TPO membrane. 

TPO Roofing Installation Process

These are the steps to install a TPO roof.

Preparation: The roof surface is prepared by removing old roofing materials, repairing damaged areas, and cleaning the surface to ensure proper adhesion.

Installation of Insulation: A layer of insulation is typically installed over the roof deck to provide thermal protection and improve energy efficiency.

Membrane Installation: The membrane is rolled out across the roof surface. To attach the TPO membrane to the roof deck or cover board, the contractor can either ruse adhesive or they can fasten it mechanically. Once the membrane is well fitted, the contractor then returns to use a hot air gun to hot air weld the seams together.

Flashing Installation: Flashing materials, such as TPO-coated metal or PVC, are installed around the edges of the roof, at penetrations (such as vents and skylights), and other areas where water might collect.

Quality Control: Once the installation is complete, the roof is inspected against manufacturer’s specifications and industry standards. 

Advantages Of TPO Roofing

  1. Hot air welding of sems in TPO roofing provides a strong and durable waterproof seal that is less prone to separation.
  2. The white surface of TPO roofs reflects sunlight and heat, keeping the building cool and reducing energy costs.
  3. Low Maintenance: TPO roofing requires little maintenance and can be easily cleaned with soap and water.

Disadvantages Of TPO Rubber: What Are The Problems With TPO Roof?

  1. If TPO sems re improperly welded, they may come loose and lead to leaks.
  2. Since TPO is  plastic, exposure to the sun over time will lead to degradation. 
  3. TPO is prone to shrinking.

TPO Roofing Frequently Asked Questions

How long will a TPO roof last?

With good care and maintenance , TPO roofing systems can last as long as 25-30 years.

Can you walk on a TPO roof?

Yes you can walk on a TPO roof. Just make sure to avoid wearing shoes with sharp heels. Also, during installation, do not walk on the hot-air-welded seams before they cool down. 

Why does a TPO roof leak?

TPO membranes are made up of layers. Over time the fillers and minerals in the upper layer are washed away, weakening the membranes and allowing water to leak into your building.

Is TPO roofing waterproof?

TPO roofing is waterproof since the seams are sealed by hot air welding. 

Guaranteed Enterprises – Your Ideal TPO & SBS Contractor

Whether you’re a homeowner or a commercial property owner, choosing a flat roof system can be difficult. If you make the right choice, you have a good roof for the next 25 years; make the wrong choice and you’ll have your contractor’s number on speed dial for the next 25 years.

GRS Remodelling is here to help you avoid the latter. Contact us today and let us handle your roofing project from consultation up until the final nail is hammered.