Mule-Hide Blog

Hail-Resistant Roofing Systems – Part 2

Posted: 11/11/2020

More Tips from Hail Country

Our last post, “Hail-Resistant Roofing Systems – Part 1,” offered tips and best practices related to single-ply membrane selection, attachment method, and adhesive choice for roofing systems that will withstand hailstorms. But that’s only the start of creating a durable, good-looking roofing system.

In this post, Mike Anderson, general manager of Clark Roofing in Waco Texas, discusses coverboards and accessories for hail-resistant roofing systems.

A Protective Coverboard

A coverboard installed between the insulation and the TPO membrane helps protect both the membrane and the insulation, providing a stable and smooth surface for the membrane to adhere to and enhancing impact resistance. The type and thickness are determined by the attachment method and the hail rating desired.

In mechanically attached systems, Clark Roofing uses DensDeck® Roof Boards or Securock® Brand Gypsum-Fiber Roof Boards.

In fully adhered systems, using primed coverboards eliminates the need to apply a primer coat of adhesive to the substrate before applying the adhesive. To achieve a Moderate hail rating (hailstones less than 1.75 inches in diameter) or Severe hail rating (hailstones 1.75 inches to 2 inches in diameter), Clark Roofing specifies DensDeck Prime Roof Boards or Securock Brand Gypsum-Fiber Roof Boards. For a Very Severe Hail rating (hailstones greater than 2 inches in diameter), they opt for oriented strand board (OSB) with a ½-inch layer of poly ISO laminated to it; a bit more resilient than the other materials, it is able to absorb the added impact from the larger hailstones.

Clark Roofing crews use Helix® Max Low-Rise Adhesive from Mule-Hide Products to bond the coverboard to the insulation. “It adheres better than any other low-rise foam adhesive we’ve used, and it’s properly mixed right out of the canisters,” Anderson said.


Prefabricated accessories are the finishing touch in creating a polished, professional-looking roof, Anderson said.

“On every roof we do, we use factory-molded components – corners, patches, pipe boots, etc. – and we use TPO-coated edge metal whenever possible,” he explained. “We don’t cut anything. It creates a very tight, organized looking roofing system. Many of our competitors fabricate and field-wrap their own accessories, and they end up being crooked, not installed correctly, or loose. You see a big difference when you compare our roofs to theirs.”

Material costs are higher with this approach, Anderson admitted. But labor savings make up some of the difference, and the company’s detailed bid documents illustrate the value of the approach by clearly explaining what the customer will be getting and the resulting benefits.

While Texas may bear more than its share of hailstorms, virtually no corner of the United States is immune. Thoughtful planning in designing and installing a building’s roofing system can help ensure it will get through the storm unscathed.

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