Asphalt may be one of the oldest materials used in roofing, but today's formulations are anything but simple. As contractors face increasing demands for impact resistance, wind performance and long-term durability, manufacturers continue to refine the asphalt technologies at the core of modern roofing systems. Toni Newsome, senior R&D leader for asphalt research and development at Owens Corning, recently discussed how asphalt formulations are evolving and what contractors should know about the material behind every shingle.

RC: What do you find most interesting or intriguing about asphalt?

TN: Because asphalt is a legacy material that has been used for centuries, it can seem like a simple, straightforward material. But as a natural resource derived from crude oil, asphalt is an ever-changing material affected by refining processes, sourcing locations, market prices, global events, composition, and availability. All of these variables create a huge challenge for asphalt formulators who need to deliver consistent quality, batch over batch. Our asphalt R&D team works with operations, quality, sourcing, and supply chain teams to bring consistency to the formulation process. They’re responsible for working with asphalts of different costs, qualities, and volumes to consistently produce the same high-quality product.

RC: What function does asphalt serve on a home’s roof?

TN: Many people are surprised to learn that there are two different asphalts in every shingle. Each shingle includes an asphaltic coating to shed water and an asphaltic sealant for securing the shingle to the one above or below it. Asphalt coatings may also be formulated to deliver a rubberizing effect for regions exposed to extreme weather and high-impact events. For example, we make the Owens Corning TruDefinition Duration FLEX shingles with SBS-modified asphalt, which enhances pliability, especially during storms. Beyond shingles, asphalt also provides nail sealability and adhesive properties for peel-and-stick underlayments that serve as the waterproofing layer in the roof system. 

RC: What properties make asphalt an ideal material for roofing?

TN: Because asphalt and water are incompatible, water essentially wants to roll off the asphalt; so it’s great for shedding water and preventing leaks. Asphalt can also be formulated for extreme durability and resilience. As extreme weather events seem to be happening more frequently, durability is really in the spotlight. We’re seeing a lot more wind-resistant and impact-resistant technology across the roof. For example, our adhesive sealants work hand in hand with robust wind-protection technologies, such as Owens Corning’s SureNail Technology.

RC: What are some myths or misconceptions about asphalt?

TN: A lot of people think all asphalt is the same, but there are hundreds of different types of asphalt formulations possible depending on the materials and processes used. Softness, viscosity, stickiness, elasticity, and how materials in the formulation “recipe” mix with other materials influence the final product. No product uses just one stream of asphalt. We need the full array.

RC: What is something that might surprise people to know about asphalt and how it has evolved?

TN: Today’s quality assurance teams have a wide range of material science tools and sophisticated instrumentation to evaluate asphalt. That wasn’t always the case. I read an account in Asphalt Magazine about a chewing test that was used in the 19^th century! No doubt about it; industry has come a long way when it comes to producing asphaltic products! 

RC: How do you expect asphaltic products to evolve over time?

TN: Durability and resiliency requirements will likely become even more important in the future. Other themes in the future may involve using more recycled or less refined materials, such as more sustainable, recycled, and bio-based materials going into asphalt. We are seeing more plant-based oils, called rejuvenators, that are being used to soften and restore the flexibility and adhesion. and durability of aged asphalts. For example, the millings from an old pavement may be softened and put into new pavement mixes with the help of rejuvenators. 

RC: Why should contractors have a greater appreciation for the science behind asphalt?

TN: Asphalt is such a huge part of our infrastructure, yet we hardly notice it. In pavement, it literally gets us where we need to go. It helps protect our homes and the people inside them. We tend to think asphalt is a simple material, but it’s not because of the complexity of making various formulations to support different purposes. Asphalt is exposed to the most heinous environments. We depend on lab technicians, engineers and chemists to design asphalt formulations to support performance and longevity.