Polyvinyl Chloride Roofing, better known as PVC roofing, has been a mainstay in the commercial roofing industry for decades. Originally produced by a German company in the 60’s, PVC roofing was quickly recognized for its exceptional performance and spread to commercial roofing contractors around the world in a matter of years.
Known for its strong chemical resistance, waterproofing, and long-term durability, PVC roofing is one of the most popular roofing types installed on buildings across Virginia and DC.
What is PVC Roofing?
PVC, or polyvinyl chloride roofing, is in the thermoplastic family of single-ply roofs, meaning all of its seams are heat-welded together. Having been in the field longer than TPO, PVC is often preferred by building envelope professionals because of its longer track record for success, overall cost effectiveness, and its durability and weather resistance.
During its inception in the 1960’s, multiple iterations of PVC roofing were developed and tested, some prioritizing polyester reinforcement over membrane thickness and vice versa, others tweaking the amount of plasticizer mixed into the material to make it more flexible and less brittle.
What they ultimately learned was the importance of maintaining the very delicate balance between flexibility, reinforcement, and membrane thickness that have made PVC a reliable mainstay in commercial roofing for well over 50 years.
There are 3 major types of PVC roofing:
PVC: this is the standard and most cost-effective PVC formulation. Liquid plasticizers mixed in with the sheet offer higher flexibility than other roof types.
KEE: solid plasticizer which offers the most reliable long-term performance of the PVC roofing family. That also makes it the priciest option.
Elvaloy: a mix of solid plasticizer and liquid plasticizer that provides the “best of both worlds” for long-term durability and cost effectiveness.
What are PVC Roofing’s biggest advantages?
In addition to its long track record of success, PVC roofing is also well-known for its chemical resistance, long-term weathering abilities, fire resistance, puncture resistance, and relatively easy maintenance and repairs.
Another massive advantage is its seam technology. PVC seams and accessories are heat-welded together, making the roof monolithic and more resistant to elements like water, wind, and weather. Compared to TPO, PVC offers many of the same benefits with the addition of better chemical resistance and a long track record of performance in the field.
PVC roofing also includes a variety of installation options, making it a malleable choice for building owners with unique buildings or needs.
What building types is PVC Roofing best for?
Like TPO and other single-ply membrane roofs, PVC is highly versatile and is a suitable solution for a wide variety of building types.
It’s biggest differentiator from other single-ply roofs is its stronger chemical resistance. That makes it an ideal choice for buildings that have any sort of chemical presence, such as airports, or for buildings that deal with a higher than average amount of grease, like restaurants.
What are PVC Roofing’s material and labor costs?
Labor costs for PVC roofing fall right in line with TPO roofing and other single-ply membrane roofing systems.
PVC material, however, is more expensive than TPO. PVC material is $0.80-0.90 per sq ft versus TPO’s $0.50-0.60, despite both almost always carrying similar 20-year warranties. Accessories and supplemental materials for PVC, such as its field membrane, accessories, adhesive, and membrane cleaner, are also more expensive than its TPO counterpart. PVC also isn’t cross-compatible in any way with other single-ply membrane roofs.
TPO and EPDM, on the other hand, are considered “sister technologies” in many ways, so much so that you can combine both roofing technologies to create a roofing system that is warranted by certain manufacturers.
As a result, PVC repairs are on-average more expensive than TPO or EPDM, mainly due to the material cost themselves.
How is PVC Roofing repaired?
PVC roofing repairs are relatively easy compared to other major roofing systems.
Thanks to its heat-welded seam technology, everyday punctures are often fixed by cleaning the area and heat-welding a new piece of PVC over it. Because of the hazardous nature of heat welding, these repairs still require certified commercial roofing contractors (ie. hand welders) as well as specialized equipment to ensure it’s done right.
This is not an area where you want to cut corners, so make sure you hire a professional you can trust.
How is PVC Roofing installed?
PVC roofing provides a number of different installation methods to adapt to you and your building’s needs.
Mechanically fastened roofs is one of the most common single-ply roofing installation methods. By screwing the seam and the insulation down to the structural deck with barbed plates and fasteners, this is a popular and cost effective method. The catch? It doesn’t offer as much wind uplift performance.
Rhinobond is a higher-end variation of a mechanically fastened system with better wind uplift performance. It’s attached to the structure then induction-welded to the membrane. Not only is the material more expensive, but a contractor would also need to purchase or rent a Rhinobond machine to install PVC using this method.
Adhered roofs use a chemical glue to adhere the field and flashing membrane, which helps create a smooth, flat surface that’s flush with the insulation and substrate. Most building owners agree that this is the most aesthetically-pleasing option and offers higher wind uplift performance to boot. Typically this method costs more than others.
Lastly, PVC roofs can also be ballasted, but we typically don’t prescribe or install using this method unless the existing roofing system that we are replacing is ballasted.
How is PVC Roofing insulated?
PVC roofing offers 3 types of insulation, all with different costs and R-values.
What’s an R Value? Good question. Simply put, it measures a material’s resistance to thermal movement. That means the higher the number, the more effective it is at retaining heat.
Polyisocyanurate, or polyiso, is the go-to insulation method thanks to its higher R-value per inch. The downside is its higher flammability, meaning it’s not a viable option for buildings with certain fire restrictions or wooden decks (ex. Class A).
Expanded Polystyrene, or EPS, offers a higher R-value per dollar but is only used on tapered roofs.
Extruded Polystyrene, or XPS, has a blue, green, or pink color and falls in between polyiso and EPS for price and R-value.
PVC roofing has excellent fire resistance, chemical resistance, flexibility, durability, and cost-effectiveness. On top of that, 25% of its composition is recycled, making it a more environmentally friendly option as well.
To learn more about PVC roofing, check out our dedicated page right here. Ready to have a roofing professional perform a walkthrough and full diagnosis? Give us a call today!