What are PVC and TPO?

First, let’s establish some basic definitions. Both PVC (polyvinyl chloride) and TPO (thermoplastic polyolefin) are thermoplastics, meaning they can be repeatedly softened by heating and hardened by cooling, allowing them to be heat-welded together. This heat-weldability is a key advantage of thermoplastics in roofing.

While both are thermoplastics, PVC and TPO differ significantly in many areas. PVC: As the name suggests, PVC contains chloride and is derived from oil, consisting of various polymers and additives. Think of a pool liner, to understand PVC’s flexibility. TPO: TPO is often described as an elastomer-modified polypropylene, essentially polypropylene with a synthetic rubber component (ethylene polymer). While also a thermoplastic, TPO tends to be stiffer and harder than PVC.

 

Fire Retardancy

PVC naturally possesses exceptional flame retardancy due to its chlorine content. TPO, on the other hand, relies entirely on added fire retardants to achieve flame resistance. This makes PVC a potentially better choice for industrial sites with higher fire risks. Click here for a fire test video.

 

Flexibility and Weldability

PVC is inherently more flexible and generally easier to weld due to its softer nature, providing a visual “bleed” during welding that indicates proper fusion. TPO, being stiffer, doesn’t offer this visual feedback, requiring more careful attention to temperature and technique to avoid “cold welds”.

 

Chemical Resistance

PVC exhibits superior resistance to a wider range of chemicals, including animal fats, food grease, oils, lubricants, and hydrocarbons. TPO does not hold up as well in these environments – therefore, PVC is often recommended for environments like restaurants and food production facilities where such chemical exposure is likely.

 

Environmental Considerations

However, PVC contains chlorine and plasticizers, which have raised environmental concerns regarding disposal in landfills if not properly recycled. TPO does not contain these substances, giving it an environmental advantage in that regard. Both PVC and TPO are recyclable.

 

Scrim (Reinforcement Layer)

Both PVC and TPO membranes have a reinforcing scrim layer between the top and bottom plies. However, PVC typically uses a non-wicking scrim, meaning it doesn’t absorb water…. TPO generally uses a low-wick scrim, which can absorb some moisture if the edge is cut and exposed, requiring the use of cut edge sealants.

 

Flexibility and Weldability

PVC is inherently more flexible and generally easier to weld due to its softer nature, providing a visual “bleed” during welding that indicates proper fusion. TPO, being stiffer, doesn’t offer this visual feedback, requiring more careful attention to temperature and technique to avoid “cold welds”.

 

Cost, Longevity and Quality

PVC has a longer track record in the commercial roofing industry, dating back to the 1960s in North America. While TPO was introduced in the 1990s and has seen significant advancements, its long-term performance can be more variable depending on the manufacturer and formulation. As we note in our “Roofing Uncovered” Podcast (Episode 4 PVC vs. TPO), in the US market, TPO is often the lowest-cost option, while in Europe, high-quality TPO can be more expensive than PVC due to different formulations and material usage.

 

Smooth vs. Textured Thermoplastics

In a recent University study, Textured Thermoplastic membranes emerged as a critical minimum for roof safety, while materials like smooth TPO, PVC, and silicone performing the worst in the study. As highlighted in Episode 3 “Roofing Uncovered” podcast (Episode 3 – Iowa State University (ISU) Roof Slip and Falls Study), both smooth TPO and PVC membranes are extremely dangerous when wet, behaving like “ice skating rinks”. This is a critical safety concern that we at Triton Inc. take very seriously. This is why, we only supply textured thermoplastic membranes. These textured surfaces offer significantly improved slip resistance, even in wet or icy conditions, drastically reducing the risk of slips and falls. Click here to learn more about the Research Study.

 

Which One Wins? It Depends.

Ultimately, the “winner” in the PVC vs. TPO debate depends on the specific needs and priorities of your project.

Consider PVC for projects requiring exceptional chemical resistance, inherent fire retardancy, ease of repair, and a long, proven track record, especially in demanding environments. Consider TPO as a potentially cost-effective and environmentally conscious option, but be sure to research the manufacturer’s quality and track record.

 

At Triton Inc., our focus is on providing safe and durable roofing solutions. We encourage you to carefully consider the unique characteristics of each material and, most importantly, to prioritize safety by choosing textured thermoplastic membranes for enhanced slip resistance.

 

Contact us today to discuss your specific roofing needs and explore our range of high-quality, textured, slip-resistant PVC and TPO options.

 

Click here to learn more about our slip-resistant PVC. 

 

Click here to learn more about our slip-resistant TPO.