www.wconline.com/articles/85570-eliminate-the-itch-factor

Eliminate the "Itch Factor"

March 1, 2009
Western North Carolina builders utilize exterior sheathing near historic Biltmore.



In the scenic mountain town of Asheville, N.C., the Biltmore Park Town Square is a mixed-use community that boasts a number of “firsts”-not only for the local region but also for the building industry and even the entire country.

It’s the first residential and commercial neighborhood of its kind in the center of this 400,000-resident Western North Carolina region, offering locals and visitors alike the opportunity to live, work and play all in one central location.

When complete, the Biltmore Park Town Square project will total more than a million square feet and will include specialty retail, office space, apartments, condominiums and townhomes, as well as a 165-room Hilton hotel, YMCA, movie theater and ample parking.

“The Town Square will have something for everyone, all within walking distance-from area residents eager to try a new restaurant for dinner, to business travelers in need of a hotel close to the airport, to weekend visitors in search of family entertainment in the evenings,” says Lee Thomason III, vice president for Asheville-based developer Biltmore Farms LLC.

Thomason says the Town Square also one of the first projects in the country chosen to participate in the Leadership in Energy and Environmental Design - Neighborhood Development Program pilot study that demonstrates how mixed-use developments reduce sprawl, encourage healthy living, protect the environment and reduce dependence on automobiles.

In addition, construction is underway on two Town Square structures individually pursuing LEED Certification-one, a combination of retail and office space, and the other, the Hilton Asheville.

It was during construction of the Hilton Asheville, which is slated to open this fall, where-with one of the regional building materials used on the project-architects, contractors and installers encountered a “first” of their own: a purple choice in exterior sheathing.

EXTENDED EXPOSURE

A building’s separation between the interior and exterior environments, known as the building envelope, serves as the outer shell that protects and regulates the indoor environment. The exterior walls and soffits are critical elements of any building envelope, and can be constructed with a wide variety of designs and finishes-most of which require a sheathing attached to the outside framing as a water-resistant underlayment for a variety of exterior cladding materials.

While the best way to prevent mold growth and moisture damage is, of course, to use sound design, handling and construction practices, exterior surfaces are frequently exposed to the elements for extended periods of time during the construction process. As a result, exterior sheathings and soffits have to provide a strong base that can tolerate exposure to weather conditions while at the same time being flexible enough to adapt to a variety of finishes.

National Gypsum’s Gold Bond e²XP Sheathing is a mold and moisture resistant exterior gypsum panel. Produced in National’s signature purple color, the sheathing is the latest addition to the company’s XP product line that incorporates an active technology to combat mold.

Though the sheathing wasn’t originally specified for the six-story Hilton, the project’s supplier, ProBuild, and drywall contractor, Phoenix Building Systems, had recently heard about the sheathing. They were eager to test its performance and worked with the project’s architect and general contractor to substitute the product for the 60,000-square-foot job.

“We know exterior sheathing needs to be a quality product that offers effective and reliable mold control,” says Mark Campis, the project’s architect and partner at Atlanta-based Hogan Campis Architecture. “But beyond that, we also consider installers’ preferences regarding ease of installation, workability and availability, and whenever possible, give them the opportunity to work with the products with which they’re most comfortable.”

The sheathing is made with an enhanced moisture and mold resistant core and coated fiberglass facer-a combination that has received the highest possible score for mold resistance in independent laboratory tests and can withstand up to 12 months of exposure to typical weather conditions.

But as the general contractor on the job, Scott Johnson, senior project manager with Matthews Construction Company, wasn’t just interested in the product’s effectiveness, but also in availability.

“For me, it’s the deadline that’s critical,” says Johnson. “Not only did e²XP Sheathing offer ... mold and moisture resistance, but it was readily accessible when and where we needed it and proved to be an easy-to-use upgrade compared to other sheathing methods.”

NO “ITCH FACTOR”

The product is designed to attach to the outside of sidewall and soffit framing as a water resistant underlayment for various external materials and can be used in both wood and metal stud construction to provide fire resistance, weather protection and to add structural strength. In addition, it can be used as a substrate for a number of air and water resistant barriers, such as building wraps, self-adhesive membranes and liquid-applied coatings; as a component in curtainwall or EIFS; and under exterior finishes including metal, vinyl, wood or fiber-cement siding, brick or stone veneer and conventional stucco.

In addition to scoring and snapping easily, the sheathing features a special coating on its front, back and sides to allow for easier handling.

“It doesn’t shed fibers when it breaks or have the ‘itch factor’ of other sheathing products we’ve used on other jobs,” says Red Thomas, general superintendent for Phoenix. “We had absolutely no issues whatsoever-my team just loved it.”W&C