TPO (thermoplastic polyolefin) and PVC (polyvinyl chloride) are two of the most utilized single-ply membrane options for low-slope commercial roofs. These thermoplastic materials are very similar in installation and performance and are often mistaken for one another; however, there are distinct differences between the two.
Before replacing your commercial roof, it’s essential to understand the differences between TPO and PVC roofing systems to make the best choice for your project specifications and budget.
This article will provide an overview of TPO and PVC roofing, discussing each material’s characteristics, pros, and cons and outlining general selection considerations.
About TPO Roofing
TPO commercial roofing systems were initially developed in the late 1980s and have evolved rapidly over the last several decades. TPO roofing membranes are created by binding ethylene or polyethylene to rubber, creating flexible sheets reinforced with a polyester mat. During manufacturing, TPO sheets are infused with UV light inhibitors, flame retarders, and biocides that deter mold, bacteria, and pests.
About PVC Roofing
PVC commercial roofing systems were developed in the 1960s as a cost-effective replacement for traditional built-up roofing (BUR) systems. PVC was quickly adopted and became very popular due to its durability, chemical resistance, and ease of maintenance. Manufacturers add plasticizers to polymerized vinyl chloride monomers when creating PVC roofing sheets to create a durable, flexible commercial roofing membrane. A PVC roofing sheet contains two PVC layers with polyester reinforcement. The top sheet is infused with additives to increase UV resistance. The bottom sheet contains plasticizers that make the material more flexible and simplify installation.
Pros of TPO Roofing
There are many reasons why building owners, property managers, and architects find TPO roofing attractive. The main benefit is the cost savings compared to other roofing systems. When deciding if TPO is the best material for your commercial roof, you should consider the following factors:
Cost-effectiveness: TPO systems are generally less expensive than other commercial roofing systems, making them a cost-effective option for many buildings.
Easy Installation: They are lightweight and easy to install, reducing labor costs and reducing the disruption to building operations during the installation process. The sheets are wide, which means fewer seams.
Environmental Benefits: The material is recyclable, and some systems contain a high percentage of recycled materials, making them an environmentally friendly option for commercial buildings.
Cons of TPO Roofing
A few factors could make TPO roofing a less suitable option.
The first concern is lifespan and degradation over time. Though TPO is known for its initial strength, it can be vulnerable to damage from UV light, especially if the roof does not have adequate UV inhibitors. This can result in the material becoming brittle and cracking over time. Here are some additional factors to consider:
Sensitivity to Chemicals: TPO roofs are sensitive to certain chemicals, such as solvents and oils, which can cause the material to deteriorate. This makes TPO a poor choice for most manufacturing facilities, restaurants, and chemical storage facilities.
Installation Challenges: While TPO roofs are simpler to install than many commercial roofing systems, the rigidity of the membrane can cause it not to form, as well as PVC. Improper installation will often result in leaks, punctures, and other problems.
Longevity: TPO is the newer of the two materials, making the future of the chemical formula unknown.
Pros of PVC Roofing
PVC commercial roofing systems have been available for much longer than TPO systems and have more historical data available to demonstrate the value of the material. A track record of effectiveness can provide peace of mind for building owners, property managers, and architects.
PVC is the far superior option in terms of resistance to chemicals. Industrial applications, chemical storage facilities, restaurants, and any commercial building that faces heavy exposure to chemicals in the environment would likely be best served with a PVC commercial roofing system. When considering a PVC commercial roofing system, take these factors into account:
Durability: PVC roofs are incredibly durable and resistant to tearing, punctures, and other physical damage. They also have a long lifespan, often up to 30 years or more, with proper maintenance.
Flexibility: The material's flexibility makes it more viable for complicated roofing architecture with multiple breaks in the roofline.
Weather Resistance: This material is highly resistant to extreme temperatures, UV rays, and weather conditions, making them a good choice for buildings located in areas with harsh climates.
Easy to Install: PVC roofs are easy to install, and the installation process can often be completed more quickly than other roofing systems. This can result in lower labor costs and a faster return on investment. The installation process requires fewer seams, minimizing the risk of water intrusion where the system is weakest.
Environmentally Friendly: PVC roofs are made from a recyclable material, which makes them a more environmentally friendly option than other commercial roofing systems.
Wide Color Selection: PVC systems are available in a wide selection of colors, allowing building owners and managers to choose a color that fits the aesthetic of their building.
Resistant to Ponding Water: The materials used in PVC roofing membranes were originally developed for use as a pond liner over 50 years ago.
Cons of PVC Roofing
Cost is a significant factor in any commercial roofing installation. PVC is generally more expensive than TPO, so weighing the benefits concerning your specific application should be considered.
Here are some cons of PVC systems:
High Expansion and Contraction: PVC roofs can expand and contract significantly in response to changes in temperature, which can result in stress on the roof and potential leaks if not properly installed.
Cost: Materials and installation of PVC roofs generally run about 15-20% higher than a comparable TPO roofing system.
Degradation: Although PVC is considered more durable than TPO, certain conditions may cause the system to degrade more quickly. The plasticizers that make PVC flexible are prone to break down when exposed to high heat or become brittle in extremely cold conditions.
Which Should You Choose?
If you are planning to replace your current commercial roof and are trying to decide whether TPO or PVC is the right choice, there are many factors to consider. Budget is always important, and other things like the purpose of your building and its physical location will inform the decision.
Both thermoplastic materials will provide an effective flat roofing solution with added defense against UV rays and water intrusion. The materials have UV-resistant properties, which is helpful in hot climates in the Southeast, working to reduce energy bills. Ultimately the other environmental concerns your building will be exposed to, and your long-term expectations for the durability of your roofing system should be weighed.
You don’t have to make this decision on your own. Register Roofing has been installing commercial roofing systems around the Southeast, including TPO and PVC, for over 40 years. We can work with you to evaluate your situation from top to bottom and advise you on the best roof for your application.
Contact us today to simplify your TPO versus PVC decision.