Roof cover boards have long been recognized as a key component of good roof design, acting as a protective substrate between the roofing membrane and insulation.

For Kia Motors’ manufacturing plant in West Point, Ga., the roof system installed featured Georgia-Pacific DensDeck fiberglass-mat gypsum board on top of two layers of isocyanurate insulation. The system was topped by a 60-mil TPO membrane manufactured by Firestone Building Products.

Roof cover boards have long been recognized as a key component of good roof design, acting as a protective substrate between the roofing membrane and insulation.

Industrial buildings in particular require a cover board solution that is durable enough to withstand construction loads and maintenance traffic, as well as hail impact, wind uplift and snow loads. A roof board’s fire resistance, moisture resistance and other unique characteristics are also critical when choosing a product for a specific industrial application.

Special requirements for environmental conditions or processes that are unique to an industry are also major materials considerations for roofing contractors selecting products for a project.

For example, auto manufacturing plants have a number of such unique requirements. The painting and detailing process occurring daily at these plants is extremely sensitive to particulate matter, and paint rooms cannot tolerate silicone in the environment.

Georgia-Pacific DensDeck fiberglass-mat gypsum board was chosen based on its ability to meet the project’s needs. A silicone-free version was special ordered for the project.

Kia Motors Plant

When Kia Motors was undergoing a $1 billion project to build its first United States manufacturing plant in West Point, Ga., selecting the right roof board was an important aspect of the project.

Kia and its primary roof design expert for the project, All South Subcontractors Inc. of Birmingham, Ala., were faced with many roof board choices, including asphaltic, mineral fiberboard, plywood/OSB, wood fiberboard, perlite, and paper-faced gypsum. In addition, the unique particulars and needs of an auto manufacturing plant were the key factors in All South’s research and specifying process.

Georgia-Pacific DensDeck fiberglass-mat gypsum board was chosen based on its ability to meet the project’s needs. The 60-mil TPO membrane specified was provided by Firestone Building Products.

“Georgia-Pacific Gypsum was a great partner with us, working with Firestone to deliver all of the roofing materials without delays to the project,” said Austin Lacey, the Kia project manager for All South.

“Due to the large capital investment required to construct an automobile manufacturing plant, protecting the structure and assets was of paramount concern, so durability and fire resistance were key considerations in Kia’s roof design,” explained Reinhard Schneider, DensDeck Product Manager for Georgia-Pacific. “A durable single-ply membrane layered over a strong high-density cover board like DensDeck ensures adherence to the unique demands of a building that will sustain more maintenance foot traffic than many industrial structures, while also protecting the plant’s roof and contents from moisture and fire damage.”

Special Needs,  Special Solutions

According to Lacey, the Kia project product delivery presented Georgia-Pacific Gypsum with a formidable challenge - deliver a silicone-free version of DensDeck roof board to meet the automotive plant’s special needs.

Schneider noted Georgia-Pacific was able to address the special request with a timely special order. Georgia-Pacific Gypsum made a special run to produce the silicone-free product, and the company was able to produce and deliver it with a two-week lead time.

“DensDeck roof board can be manufactured to be silicone-free,” Schneider said. “The durability of the board and the availability of a non-silicone containing product made the Kia project an ideal situation in which to apply the versatile characteristics of DensDeck.”

For the Kia project, a quarter-inch DensDeck cover board was used as the roof substrate over two layers of isocyanurate insulation. While DensDeck is versatile enough to use underneath a variety of roofing membranes, All South selected the Firestone 60-mil TPO membrane, noting DensDeck poses advantages for a TPO application. “DensDeck roof board is superior for TPO membranes because it is a rigid substrate and it makes TPO lay much better, giving a really nice looking finish to the product,” said Lacey

“The biggest reason DensDeck roof board is often selected is its history of performance,” noted Schneider. “Over 20 years of positive performance and industry recognition gives a construction specifier the assurance that DensDeck will perform as it is described.”

All South indicates it often uses DensDeck roof board on new construction projects, but Lacey also noted that it is ideal for renovation projects where the roof’s R-values - the measure of thermal resistance used to compare insulation - are already in place. “Whether you are working with lightweight concrete or poly roofing, DensDeck cover board goes right over the insulation and adheres easily to the substrate,” he said, noting that the brand’s cover boards work particularly well with re-roofing projects in which the roof’s height requirements might be impacted by adding new insulation and substrate.

“If you add too much height in a re-roof project, you can have trouble meeting manufacturer requirements for ISO insulation,” Lacey explained. “The quarter- and half-inch DensDeck roof board has minimal impact on roof height and can be installed easily around existing roof equipment and other roof structures.”

A Durable System

Lacey and Schneider both noted that many of the consultants and architects they work with specify DensDeck roof board because its rigidness and durability hold up better than other substrates and deliver a longer-lasting roof system.

In addition to its strength and appearance properties, DensDeck roof board is non-combustible, as described and tested in accordance with ASTM E 136, offering superior fire resistance with zero flame spread and zero smoke developing when tested. The 5⁄8-inch DensDeck Fireguard roof board has also been classified by Underwriters Laboratories for use in certain fire-rated assemblies. DensDeck roof board is also highly moisture-resistant, Schneider noted. It will not wick moisture or delaminate with exposure to water, protecting the vulnerable insulation layer. Its fiberglass, inorganic facers do not support mold growth, supporting the building’s long-term health and sustainability.

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