Winter 2020
Highlights from this Month's e-Newsletter
Feature
Retrofits and Remodels
engineered wood, A cost-effective replacement for hard-to-source timbers in historical remodels
Structural engineered wood products, manufactured in a wide variety of sizes and finishes, are well-suited for use in historical retrofits. Here's two examples of how designers took advantage of engineered wood's strenghts: The Appleton Mills project, which needed to use historically suitable materials approved by the National Park Service, and the Audrain Museum, which required an extra-strong floor on which to display its heavy collection of antique automobiles.
Appleton Mills, Lowell, Massachusetts
The Appleton Mills complex, located in a historically significant urban National Park, includes 5 million square feet of space. The original structure was built in the 1870s with a second building added in 1906. The original building relied primarily on 12- to 15-inch-thick southern yellow pine (SYP) heavy timbers, spaced 9 feet on center, and 3-inch thick SYP decking.
At the time the project began, with a goal of creating live/work lofts for artists, the buildings had been abandoned for about 20 years and were leaking in areas where the roof was missing. Nearly 40% of the floors had collapsed from rot. The timbers couldn’t be saved—two decades of exposure had deteriorated them beyond repair—and the developers were required to replace them with wood to meet historical regulations. As a result, the structures had to be completely gutted, including the framing, down to just the existing 3-foot-thick brick walls.
The design team turned to glulam, which the National Park Service determined was a suitable replacement for the heavy timbers that can no longer be found. APA member Rosboro provided 2-1/4-inch-by-21-1/2-inch glulam for the floor deck. “The glulam planks were integral to building the structure on schedule and safely,” says Matt Bagedonow, vice president of CWC Builders, noting that the glulam allowed the team to maintain temporary steel bracing for the existing walls and remove it as the new floors were added, incrementally increasing the lateral stability of the walls until they were fully braced by the new floors. In addition, installers used the glulam planks to create a platform to work as they built upward. “Also, structurally, we have to provide a diaphragm action for the floor; we were able to prove we could do that with the planks by screwing them together. Glulam was really key to getting this project done. It was indispensable.”
Along with the floor system, the builders used glulam for all of the girders and floor beams, as well as to replace 8x8 heavy timber columns in the older building. “The glulam allowed us to replace the heavy timbers while still meeting historical requirements,” says Bagedonow. The industrial-grade beams were stained and left exposed in the 12- to 13-foot ceilings; in some of the 125 units, the floor decking above is also visible. “They look terrific,” adds Bagenow. In the second building, CWC was able to salvage, sandblast and reuse the existing cast iron columns.
Similar historical provisions had to be met with walls and fenestration, including new aluminum windows that replicate the look of the originals. For unsalvageable portions of the façade, CWC located a brickyard south of Boston that uses the same clay as the original brick, allowing the team to replicate the look and color to maintain a seamless look throughout the exterior. While the historical nature of the building’s appearance is maintained, modern amenities abound inside, including an efficient heat pump system, modern appliances and kitchens, sound-abatement strategies and a green roof.
For more information, download Case Study: Appleton Mills, Form R145. GET >
Audrain Museum, Newport, Rhode Island
The unique building was designed by New York architect Bruce Price in the early 1900s and features intricate exterior detailing. Its transformation from a worn-around-the-edges modified office building into a car museum and upscale workspace blends vintage charm and high-end appeal. On the high-ceilinged first floor, golden-era automobiles and muscle cars glisten through full-height windows. Above, new offices make better use of the space with a high-end vibe well-suited to their location.
But getting to that point required some heavy lifting from a new, more robust building frame. The car museum houses a range of vintage autos, including a WWII-era vehicle weighing in at one-and-a-half tons. Engineer Mike Camera of Camera/O’Neill Consulting Engineers knew that the original 2x12 flooring system needed to be removed and replaced to accommodate the additional weight. The team at Parker Construction kept the outer shell and the original brick bearing walls, which divide the basement into six sections. On the ground floor, the structure was framed with steel columns and 20-foot, 3-1/2-inch-by-9-1/2-inch glulam beams from APA member Anthony Forest Products, spaced 12 inches on center, spanning each bay. The glulam not only accommodated the span requirements for the frame, but also was more readily available than some of the other framing alternatives the design team considered.
Though the beams will be largely unseen in the low basement storage area and were coated with fire retardant, “The glulam was milled so well, we could have left them exposed,” says David Louttit, project manager at Parker Construction. Structural-rated Douglas fir 2x6 timbers run perpendicular to the glulam beams, with 3/4-inch tongue-and-groove CDX plywood in between. For the second-floor frame, exposed steel trusses provide an industrial look.
Along with the challenges of preserving the look and beefing up the structural frame, the construction team faced severe time constraints: a schedule with less than half the normal turnaround time. To meet the deadline, Louttit had crews on site 16 hours a day, seven days a week; they also shrink-wrapped the structure to eliminate impacts from weather.
While the project sports a new structural wood frame, the team took great care to preserve as many of the original decorative elements as possible, including ornamental metal and millwork. The front façade features the original brick, intricate terracotta around the windows and similarly ornate roof cornices. The arch-top windows reach from the first floor through to the office space upstairs. A new set of bi-fold doors, fabricated to reflect the original windows, provides access for the display vehicles.
For more information, download Case Study: Audrain Museum, Form Q125. GET >
Getting Technical
On-Demand Webinar: Shear Exhilaration
This webinar provides a top-to-bottom overview of lateral design for wood-framed structures with a focus on shear walls. As a result of this training, participants will understand load path continuity and shear wall performance, including design methodologies for shear walls. Examples from post-disaster evaluations illustrate common failure modes, and methods and outcomes of various designs of wood structural panel shear walls are compared. Participants will also be introduced to installation considerations that may affect performance and how to address these issues proactively. The force transfer around openings (FTAO) method is covered as well. AIA and ICC credits are available. GO >
Meet your educational goals with APA's cost-free webinars
APA offers both live webinars and recorded webinars for on-demand viewing. Topics include engineered wood basics, fire protection of I-joist floors, wall bracing, framing large buildings, portal frames, disaster-resilient design, sustainability and others.
Some, but not all, webinars offer CEU credit; if credit is available, it is noted in the webinar description. GO >
Texas Wood Design Symposium
Before the Storm: Building for High-Wind Resistance | February 25, 2020, 1:00 pm
This session presented by Cathy Scarince, P.E., will examine structural failures observed during storm damage assessments and the behavior of wood structures during high-wind events. Discussion will include an overview of how high wind forces work, the importance of a complete load path to building resiliency, and how good design and construction practices can improve the storm resistance of buildings. Both code requirements and APA’s above-code recommendations, which contribute to improved overall performance in the structural shell, will be reviewed. These recommendations focus on good connection details and common failure modes seen in storm-damage assessments, and can help builders to cost-effectively build safer structures. By understanding key code requirements and lateral-load concepts, building damage in storms can be minimized. LEARN MORE >
Inside the Circle
Help Wanted: You
APA is hiring. Three questions about what it's like working on our team are answered by Matt Brown, an Engineered Wood Specialist based in Indiana.
Q. What were you doing before joining APA?
A. I was the Director of Research and Development at a large Midwestern energy rating firm. My role was to manage our commercial division and look for new business opportunities. I also presented on the energy code and building science all around the Midwest. In fact, this is how I first came to know APA, by training APA's field staff on the energy code.
Q. Why did you choose APA?
A. I wanted a position that would allow me to excel in using my energy expertise but also allow me to use my structural and builder background—and I heard great things about APA from a former employee.
Q. What’s your favorite part of the job?
A. It is hard for me to pick a favorite part. I am continually growing with this role and stretching my expertise wider all the time. I enjoy the interactions with builders and designers, whether it be at an office meeting with a builder or at a training. I also enjoy my energy code and building science code work. Few people enjoy the code hearings, but I find them of great interest and enjoy the process, interaction and testifying.
View current job openings. GO >
New and Updated Publications
APA’s Engineered Wood Construction Guide, Form E30, the authoritative guide to building engineered wood floors, walls and roofs, has just been updated. The 100-page guide features information on engineered wood products and recommendations for their use in a wide range of applications in residential and commercial construction.
GET >
ANSI/APA PRG 320-2019: Standard for Performance-Rated Cross-Laminated Timber binational (U.S. and Canada) product standard, which provides requirements and test methods for qualification and quality assurance of performance-rated CLT, was recently revised by a consensus-based committee, approved by the American National Standards Institute (ANSI) and published by APA. This standard has been adopted by the 2021 International Building Code (IBC) and International Residential Code (IRC).
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