Integrated Sheathing Systems

The continued high level of activity in new multifamily housing construction in many cities and towns has put a particular burden on the availability of skilled labor to do the needed work. The rotation of crews from one jobsite to another and the coordination between different subcontractor specialties can have costly impacts on project schedules due to delays when labor pools are thin. In that regard, general contractors and developers have been seeking out ways to overcome those issues while still meeting or exceeding quality standards. One of the more common ways of addressing the skilled labor shortages is to rely more on integrated products that combine several materials or systems in a factory-controlled condition. This approach can provide a high-quality, high-performing product that requires less labor and less time in the field for installation, thus creating efficiency and savings overall.

One of the best examples where this shift in construction technique is playing out, particularly in multifamily construction, is in the use of integrated exterior wall and roof sheathing systems. This type of product is purposely designed to streamline the installation process of multiple exterior wall and roof performance needs by including structure, weather resistance, air leakage protection, and in some cases a continuous thermal barrier all in a single panel and tape system. This is a change from the previously traditional method of separately specifying and installing each of these critical exterior barriers. The move to incorporate these next-generation sheathing materials into more and more multifamily projects has also increased attention on some related construction details. Architectural designs and specifications that proactively anticipate the use of these integrated sheathing products can also include easy-to-install transitional flashing details into areas like deck ledgers, wall-to-concrete foundations, and windows. This attention to detail helps assure the continuous integrity of all barriers is maintained.

Efficiency through Panelization

In many locations, the use of panelized construction has taken hold as a further means of creating factory-based quality while reducing the need for onsite skilled labor. Prefabricated exterior wall and roof panels have been used for some time in residential and light commercial construction of all types. Traditional framing and sheathing methods are often employed with the preassembled panels shipped to the project site and set into place using appropriate equipment. Because integrated sheathing products already have multiple layers of protection, they also reduce steps in the panelization process. Hence it is becoming equally popular to use integrated sheathing in factory-constructed structural panels as much as it is site-built construction.

For either panelized or on-site work, integrated sheathing eliminates the need for other products such as housewrap air barriers, water-resistant membranes, or even additional exterior continuous insulation. The preinsulated products are available with different insulation thicknesses that can provide thermal resistance from R-3 to R-12. The insulation is intended to be installed against the studs creating the continuous insulation layer called for in many energy-conserving designs. But that also means the structural sheathing is separated from the studs by the thickness of the insulation. Hence, the engineered nature of such products addresses this condition with nailing requirements called out to meet prescriptive code requirements for bracing and shear values. Manufacturers’ engineering data and installation instructions should be followed closely for best results, particularly for multifamily structures four stories and above.

With or without insulation, integrated sheathing provides a water-resistant barrier and air barrier on the face of the exterior face of the sheathing. The seams and joints of the sheathing are addressed most commonly with tape products that are easily installed with very effective results. Such advanced acrylic seam-sealing tape can be combined with stretchable flashing tape that stretches in all-directions for efficient sealing of window sills, door frames, and penetrations. In addition, a liquid flashing material is available with these integrated systems for excellent air sealing around any rough openings with intricate curves and corners, such as recessed windows. Altogether, the taped and flashed sheathing can be specified to meet or exceed the requirements of an “enhanced drainage plane” according to ASTM-E2273-03 testing requirements. Sheathing and tape systems are even available with a 180-day exposure guarantee and a 30-year limited warranty as a testimony to their durability and effectiveness.

Aaron Mathews, director of commercial sales for Huber Engineered Woods, has seen the rapid growth in the use of integrated sheathing since it was first introduced in 2006. He points out, “The real distinction of these products is not only that they are innovated from a place of solving real job site problems but that manufacturers support their implementation from specification consideration on individual projects through product installation on the job site. From in-office presentation and specification consultations to preconstruction meeting participation, mock-wall trainings, and observation reports, the goal is to be a resource for design and construction teams throughout a project.”

Photos courtesy of Huber Engineered Woods, LLC – Zip Systems ©2018

Integrated sheathing and tape systems are popular in multifamily construction because of their high performance and jobsite labor savings.

INTEGRATED WALL SYSTEM CASE STUDY

Photo courtesy of Huber Engineered Woods, LLC – Zip Systems ©2018 and the Snavely Group (left); Image courtesy of Snavely Group/Vocon © 2018 (right)

Project: The Quarter
Location: Cleveland
Developer: The Snavely Group

The Project: Across America, old is becoming new again. Neglected urban centers are getting a second chance through renewed interest in the character and charm of historic areas. The Cleveland neighborhood of Ohio City is a prime example. It is undergoing a rapid revival, adding retail, restaurants, and residences to the industrial area. In particular, a mixed-use, mixed-income development known as The Quarter is adding to that revival. “The building has 194 market-rate apartments and 10,000 square feet of leasable space,” says Greg Osborne, vice president of project management with Snavely Group. “One of our tenants on the first floor is The Music Settlement, a local inner-city school dedicated to serving the community through arts education, and another is a small grocery store.”

The Challenge: Demand is high for access to this real estate, so to meet expectations, real estate must become available as soon as possible. Ohio City is poised to see an influx of affluent residents and shoppers, and developers are pursuing not only fast-paced construction cycles but also modern designs that meet high-performance building enclosure standards. When the Snavely Group began construction on the mixed-use project in late 2016, it knew the project needed to be timely without sacrificing quality.

The Solution: Through meetings with the architectural and engineering team, Snavely opted for the best-performing products for the job, among them integrated sheathing that included the water barrier, continuous exterior insulation, and sealing tape. It also decided to have the integrated sheathing incorporated into prefabricated wall panels to accommodate the tight scheduling strategy. According to Osborne, “We had used OSB on other buildings that we then had to go back and waterproof. Why not put up something with integrated waterproof coating to save labor? It also made sense in terms of time and energy, and it helped us achieve code requirements for continuous exterior insulation.”

Mark McClaine, sales manager with 84 Lumber, says the walls of the project were panelized at the company’s panel facility and put together by 84 Lumber’s installed framing services. “When we are weatherizing a building, product integrity is vital, and that’s especially true with The Quarter,” he explains. “The building is large, about 270,000 square feet and five stories high, and there is limited access. When we were framing and installing panels, we could only do two-thirds of the building. After the roof was installed, we came back to do the last one-third.”

Osborne added that in addition to the energy-efficiency benefits offered by the built-in continuous insulation and air barrier with the integrated sheathing, the panels are completely weatherized. Instead of using traditional OSB and having a waterproofing subcontractor come out to the site, the panels could be installed without the worry or hassle of additional steps, saving his team time and money.

The Result: The integrated sheathing and panel system proved to be not only a top-quality product but also a huge schedule saver. Osborne points out, “Time is a factor with every job now in the apartment market—it’s a race. Every month you aren’t leasing is big money lost. At the end of the day, integrated sheathing panels are an important part of the project.”