By Bim Fischer
If structural insulated panels (SIPs) grew in the forest as trees do, it’s likely stick framing never would have taken off. Given a choice between installing large section SIP walls, roofs and floors at one time versus time-consuming cutting and nailing of hundreds of individual boards, people historically would have gone with the simpler SIP construction. Today, SIPs only seem more challenging because they’re not the traditional framing method most builders learned when starting out.
In recent years, though, more contractors have discovered firsthand that it is fast and straightforward to build with SIPs. Rural builders have been among the leaders in switching to energy-efficient SIP construction, including commercial and government buildings in small towns, schools on Native American reservations, and numerous other building types and locations. Working with SIPs involves many of the same basic skills as typical framing techniques, so there’s not a steep learning curve.
One way SIPs make construction easier is they arrive at the jobsite pre-cut and sized for use in a specific part of the building. Easy-to-interpret plans show where crews should place each individually labeled panel. “With the pre-built panels, you just have to piece the building together like a puzzle,” says Glen Kamerman, partner with Kamerman Construction (Manhattan, Montana). Kamerman has built with SIPs on various projects, ranging from a chuckwagon-themed restaurant in Cody, Wyoming, to a four-story college dormitory in Rock Springs, Wyoming. Recently, his company was part of a team that built the Little Big Horn College Health & Wellness Center in Crow Agency, Montana. The project is a 35,000-sq. ft. NCAA gymnasium seating approximately 1,300 people with community spaces for aerobics, weight lifting and cardiovascular fitness. (See “Project Profile: SIPs help meet tight construction schedule during harsh Montana winter.”)
Manufacturers can provide SIPs in large-size sections (up to 8 by 24 ft.), so it’s possible to erect entire walls and roofs in a matter of hours instead of days, depending on the project. Commenting on the SIPs installation for the Little Big Horn job, Kamerman notes, “The SIPs were really accurately constructed and went together well. Using Premier SIPs probably saved about 15 – 20 percent or better on the installation time.” Another project team member, Matt Anderson, owner of Compass Consulting Engineers (Bozeman, Montana), adds, “SIPs really helped us meet the accelerated project schedule. SIP shop drawings were done concurrently with design, so by the time we released the foundation package, the SIPs were being fabricated in the shop. The erection was extremely fast and in no time at all we were dried in.”
In addition to availability in large, pre-sized sections, SIP producers fabricate the panels to simplify construction in several other ways. For example, contractors can order SIPs with pre-cut window and door openings, including arches and other curves, saving on the complexities of framing multiple individual openings. In some cases, installation of structural headers is not necessary with SIPs, further reducing the steps involved with constructing openings. SIPs also are available with pre-cut electrical chases, which allow for much easier installation of wiring than cutting numerous holes through studs in a stick-framed building. Finally, since the insulation is integrated directly into the panels, there’s no need for separate steps to frame and insulate the structure.
A skilled framing crew typically can learn the steps for installing SIPs in a matter of hours, and quickly become proficient in working with them. Because SIPs are made of wood (OSB sheathing on both sides of an insulating foam core), they are easy to nail, saw and drill similar to traditional framing.
The steps for installing SIPs are not complicated, and require common construction tools. In short, contractors use cranes to lift each panel into place and attach them to other parts of the structure with nails and long screws, and in some cases, straps and connecting plates. Individual SIPs typically join together with a block spline, a lumber spline or wood I-joist. Once the panels are in place, contractors nail the splines according to the nailing pattern shown on shop drawings. Mastic applied to all wood-to-wood, wood-to-foam and foam-to-foam interfaces helps seal the connections.
While some contractors choose SIPs for their ease of use and fast installation, a primary reason for their growing popularity is their energy efficiency. SIPs create a high-performance building envelope that can help reduce energy consumption up to 60 percent. U.S. Department of Energy research shows that SIP construction is about 15 times more airtight than stick framing with fiberglass batts. In blower door tests, DOE found that a SIP room had a leakage rate of 8 cubic feet per minute at 50 pascals (CFM50) versus 121 CFM50 for conventional wood framing. SIPs also have lower thermal bridging since their insulating foam core is not interrupted by studs or other framing members. As a result, SIPs have about 47 percent higher whole-wall R-values than stick-framed walls of similar thickness.
Expanding upon these findings, research commissioned by the EPS Molders Association demonstrated the average energy savings over 50 years for a SIP home in the U.S. was 9.9 times greater than the energy needed to produce and deliver the SIPs compared to traditional stick framing. Such “life cycle analyses (LCA)” demonstrate SIPs’ long-term environmental advantages and role in helping slow carbon emissions.
To learn more about other green building and construction efficiency benefits of SIPs and how to get started with using them, contact a SIP manufacturer or the Structural Insulated Panel Association (SIPA).
Bim Fischer is the Central Region Sales Manager for Premier SIPS by Insulfoam, North America’s largest SIP manufacturer and the leader in the research, development and manufacturing of high-performance, energy-efficient panels. (800) 275-7086, www.premiersips.com/bc
Project Profile: SIPs help meet tight construction schedule during harsh Montana winter
The project team for the Little Big Horn College Health & Wellness Center faced a daunting schedule. Time was running out to use a government grant for the project, so the team needed to start construction (moving dirt and pouring the foundation slab) even before they finalized the building design. Adding to the timing challenges, they had to construct the building’s shell during one of the coldest Montana winters in 20 years.
On top of requiring rapid completion, the College (of the Apsàalooke Nation – Crow Tribe of Montana) wanted a very green, energy-efficient building targeted to LEED Platinum standards. This commitment to the environment reinforces the center’s role in supporting healthy living and respects the tribe’s historic, cultural and artistic way of life.
Since the owner, architect and general contractor used an Integrated Project Delivery (IPD) approach, all parties had a strong stake in working together to address the schedule and green building needs. Rather than operating under separate contracts for design and construction, with the IPD the participants all signed one contract focused on successful completion of the project. “This allowed every team member to bring their best ideas to the table and collaborate on solutions,” noted Scott Moore, Project Manager with BNIM Architects.
One of those ideas was to use Premier Structural Insulated Panels (SIPs) for the exterior walls and roof. “SIPs meet a number of needs with just one system,” said Doug Morley, Principal Architect with Springer Group Architects. “They install fast, insulate well and are strong. Other than in the large gymnasium, this reduced the need for a secondary support structure in the building and saved a bunch of time and money.”
In addition to rapid construction and high strength, the SIPs play a key role in the building’s high energy efficiency design. The large-size panels have fewer gaps requiring sealing than other construction methods and provide continuous insulation throughout the walls and roof. “Energy savings is a big part of getting to the LEED Platinum goal,” said Ben Mitchell, Project Manager with Fisher Construction, general contractor. “It’s hard to get a gym to meet any energy code, let alone LEED Platinum, but the SIPs provide a super energy-efficient envelope – much better than we could get from other products for the same labor and material costs.”
The Health & Wellness Center is a major addition to the Little Big Horn College campus and is designed to serve students and the surrounding community. The design includes an NCAA gymnasium seating approximately 1,300 people; spaces for aerobics/community gathering, weight lifting and cardiovascular fitness; locker rooms; and support facilities. Beyond the high-performance building envelope, some of the center’s other green features include overhead prismatic skylights and sun-shading devices – to reduce reliance on artificial lighting and mechanical heating and cooling systems – and on-site rainwater detention.
Project: Little Big Horn College Health and Wellness Center, Crow Agency, Montana
Size: 35,000 sq. ft.
SIPs installed: 70,000 square feet of wall and roof panels
Scheduled Completion: Summer 2011
Architect of Record: Springer Group Architects, Bozeman, Montana
Design Architect & Green Building Consultant: BNIM Architects, Kansas City, Missouri
Structural Engineer of Record: Compass Consulting Engineers, Bozeman, Montana
Mechanical/Electrical/Plumbing Engineers: Three Rivers Engineering, Bozeman Montana
General Contractor: Fisher Construction, Billings, Montana
SIP Installation Contractor: Kamerman Construction, Manhattan, Montana
SIP Manufacturer: Premier SIPs by Insulfoam, Tacoma, Washington