All Together Now
A panelized EIFS project requires good coordination between the architect, general contractor and plastering contractor, and seamless teamwork is paramount to a successful installation. This concept is also critical within the plastering company itself: the design team, fabrication shop, field installation crews and delivery team must work well together for panelized EIFS to work effectively.
Sunset North, a series of commercial buildings in Bellevue, Wash., was no exception to the teamwork rule. Billings & Cronn Co., of Portland, Ore., was the plastering contractor on the job.
“Billings & Cronn is an established plastering contractor with a strong track record doing quality EIFS installations in conventional and panelized construction,” says Bob Drury, executive director of the Northwest Wall & Ceiling Bureau, a wall and ceiling industry trade association based in Seattle. Billings & Cronn has a work force comprised of family generations, and father and son still work side by side in the company’s shop.
A panelized system demands critical requirements, but proponents of such a system say that with the help of a talented plastering contractor, it holds many advantages. Factory fabrication, they say, helps speed construction. Crews can assemble the light-gauge framing, attach the gypsum sheathing, apply the foam, cut grooves and decorative shapes, apply basecoat, embed mesh and spray-apply the finish coat all in a controlled environment. Quality and production can improve when tradesmen are able to work at a comfortable waist-high level, without rain, snow or wind to contend with.
In contrast, site fabrication can have tradesmen lying on their backs trying to reach some difficult areas, while the cold wind is howling.
“We looked at panelization in our value-engineering phase,” says Bob Cole from the Seattle-based architectural firm Zimmer Gunsal Frasca, stressing the importance of pre-job meetings. “Panelization shaved construction time off the project.”
Some buildings are more suited to a panelized system than others. A repetitive pattern is important for the assembly-line-type construction. Unusual buildings with cut-up façades or elevations that have no repetitive pattern might not be cost effective for panelization.
“Communication is the key,” adds Jon Wright, of Billings & Cronn, which used Dryvit EIFS on the job. “The field and the shop have to coordinate schedules, shop materials, panel dimensions, site delivery and installation.”
Following are the steps generally associated with producing prefabricated EIFS panels like the ones used on the Sunset North project.
Step one: PlanningThe first step in the design/bid process is assigning codes to the panels for assembly and installation procedures. Panels are detailed with specific dimensions for shop fabrication, and these dimensions must coincide with the framework of the structure to which the panels will be attached. Even small changes in the structural frame can be disastrous.
Step two: FabricationOnce the panels are categorized, a blueprint is made of each style or shape. The panels are then manufactured to exacting standards. After the steel frames are cut and welded, using templates to ensure uniformity, they move on to receive a sheathing material like Dens-Glass Gold by G-P Gypsum Corp.
Next, the EPS foam is bonded to the sheathing, and grooves and reveals are cut into the foam. After rasping and sanding, the panels have a mesh troweled into the basecoat materials, and the finish coat is sprayed or troweled over the basecoat.
Finally, the panels are loaded onto trucks and await shipment to the job site.
Step three: Final installationOnce on the job site, the panels are lifted and placed on the building. Billings & Cronn has developed a simple “quick release” system that allows the panels to be held safely in place until final adjustments and attachment can be done at a later time. This method ties up the job site crane for a minimal amount of time and takes pressure off the installation crew.
The adjustment hex bolts are installed by the shop welding crews during initial fabrication. These adjustment bolts allow panels to be leveled and plumbed while on the building without the use of the lifting crane. The final step is to install a backer rod and sealant. This step is a little easier since the joints are primed, prepared and protected during the assembly phase.
The resulting project is a hit for all involved.