What is Your Roof Type?
There are many types of commercial roofs to choose from, with each offering unique advantages based on the requirements of the facility they’re protecting, the external environment, the desired life span, and the building owner’s budget. Roof types fall under three main categories: coatings, single-ply membranes, and asphalt. Within these classifications, there are a number of acronyms used to distinguish the many options available.
Single-ply roofing membranes are available in an array of materials and configurations. Thermoplastic roofing systems, such as polyvinyl chloride (PVC) and thermoplastic polyolefin (TPO), are lightweight, highly reflective, provide excellent weathering characteristics, and are resistant to UV light, punctures and tears, as well as most chemicals. And since these solutions use hot air welding to join membranes to each other, they offer excellent seam strength. Both materials are time-tested, with PVC first introduced into the market in 1956, and TPO in the early 1990s.
However, with the rising cost of asphalt over recent years, the popularity of TPO has increased to become the dominant roofing product in the US. Further, in a building with a limited lifespan, TPO membranes can be made thinner to help save on material costs while it’s typically white surface offers reflective properties that help save on energy costs.
Boasting a strong resistance to ultraviolet light and ozone with beneficial flexibility in colder temperatures, thermoset roof systems—also known as EPDM roofing—were introduced in the early 1970s. This rubber sheeting product offers long-lasting durability, versatility, simple installation, and easy maintenance and repair. To perform a repair, the installer simply cleans the surface, primes it, and applies the adhesive to both surfaces. Once the adhesive is somewhat dry and tacky, the installer sticks them together to create the seal. Most manufacturers today, however, prefer pre-manufactured sealant tapes which are less messy and labor-intensive.
Other membrane materials include Tri-Polymer Alloy (TPA) and Ketone Ethylene Ester (KEE). KEE is a material manufactured by DuPont under the brand name Elvaloy. TPA roof membranes are made from a white thermoplastic comprised of Elvaloy, blended with Chlorinated Polyethylene (CPE), and PVC, reinforced with high strength, wick-resistant polyester fabric. More chemical-resistant than PVC alone, this combination also withstands the fats and greases denotative of restaurant roofs.
While coatings are more of a maintenance item applied on top of an actual roofing product—such as single-ply membranes or asphalt—it’s useful to think of them as a separate type of roofing. The roof surface must be clean and prepared before applying a coating. The contractor must fill in any cracks and then use fabrics to reinforce those cracks, or at joints and other vulnerable areas to add strength where the roof or substrate expands and contracts. A base coat is then applied, followed by a topcoat. Different types of materials can be used for these coatings.
Similar to water-based paints, acrylic coatings are also water-based and can be easily pigmented to match virtually any color. These products are among the most cost-effective roof coatings available and are extremely durable in most environments. Acrylic roof coatings are also exceedingly dirt-resistant and maintain their aesthetic appeal over many years of use.
SEBS, or styrene-ethylene-butylene-styrene, is a versatile, durable elastomeric coating system that is about three to four times stronger than an acrylic coating, and is capable of tolerating heavy foot traffic. Unlike acrylics, SEBS coatings are not water-based. Instead, SEBS coatings use a solvent as a carrier, delivering ultra-low moisture permeability, making it resistant to water pooling and algae or fungal growth. However, products using these solvents can’t be shipped to areas that regulate the use of volatile organic compounds (VOCs), like California.
Silicone is an increasingly popular coating offered by many manufacturers. Silicone coatings are incredibly robust, adhere well, and due to their non-stick properties, have been used in cookware products for years. They also hold color well, helping roofs stay white to improve reflectivity. However, it’s essential to look at the properties of the material or products over which the coating is being applied to ensure chemical compatibility. Certain solvents used with a silicone coating could eat away at asphalt or PVC, or have other detrimental effects on the roofing products they come in contact with. As with any coating, it’s essential to speak to the manufacturer and ensure there are no compatibility or warranty issues.
While asphaltic coatings are also available, they typically don’t offer the elastomeric properties of other coatings, tending to crack over time.
Commonly viewed as a built-up roof (BUR), asphalt is one of the oldest materials used for commercial roofs. A BUR is built-up on-site (hence, the name) in a labor-intensive process beginning with insulation layers, followed by a cover board layer and attached felts. Installers apply liquid hot asphalt over the top, and then continue the process by applying another layer of felt and then another layer of liquid asphalt. To offer more competitively priced products, manufacturers began creating pre-made BURs. These modified bitumen, also known as “mod-bit”, roofs are made by encapsulating polyester or fiberglass reinforced fabric with asphalt that is blended with specific modifiers to deliver elastic properties, allowing them to be rolled up and transported. These modifiers include atactic polypropylene (APP) or styrene-butadiene-styrene (SBS). SBS applications are typically installed with either hot asphalt or cold applied adhesives. APP, on the other hand, is applied by melting the surface of the material onto a substrate via a flame source. Mod-Bit roofs are typically installed with redundancy in mind – meaning that they use multiple layers of material. The base layers are typically smooth black asphaltic sheets, while your cap sheet (or top layer) has small color granules for UV stability and durability.
Attachments to Roofs
All roofing systems need to accommodate the attachment of piping, wiring, satellite dishes, HVAC equipment, solar panels, and other mechanical systems. That’s why Anchor Products offers different solutions, including our unique U-Anchor fasteners that are compatible with any roof system.
U-Anchors are minimally invasive, install rapidly, and last longer than other fastening systems. Designed to manage various load weights while providing a waterproof anchoring solution for your equipment, U-Anchors are engineered to meet both building codes and roofing manufacturers’ warranty periods—even those that are guaranteed for 30 years. Whether they’re used on an EPDM, APP, PVC, TPO, or coated roof, U-Anchors deliver uncompromising strength and performance value for every application. Simply put, if you’re a building owner, contractor, or engineer, specifying U-Anchors streamlines and solidifies placement, protecting valuable rooftop equipment and the costly roofing systems they rest upon.