More and more owners and general contractors are turning to panelized construction in their ongoing pursuit of cost savings and shorter construction timelines. Light-gauge steel is employed for wall panel manufacturing because it is lightweight enough for convenient transportation from the factory to the job site and sturdy enough to serve as exterior curtain walls. Light-gauge steel pertains to thin steel, usually ranging from 14 to 25 gauge.
Another industry-driving trend is small, specialized roll-formers. They play a pivotal role in giving manufacturers a high degree of agency in their operations, allowing for custom-length metal studs and CAD-based kit-of-parts assembly processes. In this blog post, we’ll look at the types of Light Gauge Steel Wall Panels being constructed in the US.
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Introducing Off-site Panel Construction
True to its name, panel construction involves creating wall, floor, and roof sections within a factory, transporting them to the construction site, and then installing them using a crane, lift, or manual labor on the project site.
The degree of factory-based finishing varies. Clients can opt for basic yet effective wall panels featuring only steel framing. Alternatively, at a more intricate level, wall panels are fully sheathed, stuccoed, and insulated within the factory.
Exterior Load Baring Steel Wall Panels
Exterior load-bearing steel wall panels are prefabricated construction components made of metal studs that serve as both the structural support and the exterior cladding of a building. These panels are designed to carry the vertical and lateral loads of the structure while also providing a durable surface for the desired exterior finish completed on site.
These structural panels are comprised of a minimum of 3 5/8″ 18-gauge studs and can be as thick as 12″, employing higher gauges like 14 or 16. Their dimensions are determined by local codes, wind loads, and the number of stories. In the case of this construction project in Pennsylvania, we utilized 16-gauge 6″ studs for the first floor and 18-gauge 6″ studs for the second floor.
Usually ranging from 8 to 14 feet in width, these walls frequently span one to two stories in height. Considering shipping limitations regarding length and width is crucial. On-site installation is also a consideration, with panels designed to be installed using cranes or manually by teams of 2-3 people.
Cost effetely these exterior panel kits make the most sense when going up to 5 floors. You can use primarily metal studs with occasional supplementation of red-iron for large spans.
Light gauge Steel Structural Insulated Panels (SIPs)
Light-gauge Structural Insulated Panels (SIPs) are prefabricated construction components that integrate structural strength with energy efficiency. This is ideal for clients who’s build priority is a high level of insulation. They consist of thin steel studs enclosing an insulating material, like expanded polystyrene (EPS) or polyurethane foam. In America, they’re especially common in the north USA and Canada due to the extreme winters. SIPs when built correctly are great at:
- Minimalization of thermal bridging caused by structural metal studs
- Providing an air-tight build envelope
- Improved energy efficiency and reduced heating and cooling costs
- Securing a good LEED rating
Wally Walls in Wisconsin has built in insulation with their structural walls.
Exterior Cladding Panels
Numerous companies specialize within the industry by producing a single type of wall panel. Southern Wall Systems primarily concentrates on the exterior cladding of expansive buildings. These facade panels encompass a light-gauge steel frame with plywood or oriented strand board (OSB) serving as the substrate for applying stucco or brick finishes. These panels are sizeable and weighty, exclusively positioned using cranes due to work being conducted on multi-story buildings. A small crew manages the interior of the building, placing and affixing the panels onto the existing frame.
The advantage lies in avoiding the need to erect scaffolding on tall buildings and outsourcing skilled labor to the factory. General Contractors report that their building enclosure timelines are reduced by several months.
Hybridized Panel Construction
The most common method of building mid-rise structures is using concrete steel columns with the floors made of cast concrete with rebar reinforcement. These building depend on staircase and elevator shafts for lateral reinforcement. Steel panels are then used to in fill between floors. The light gauge steel main goal here is to bear the lateral wind load.
Considering you’re spanning only 8-12 feet (the height between floors), the typical gauge required is 18 or 16. 6″ studs are commonly employed to provide a sufficiently large cavity for commercial insulation needs. The metal panels are installed from the inside out, filling the gaps between the concrete floors. Panel builders must collaborate closely with the structural concrete teams, as tolerances are stringent.
Light Gauge Steel Wall Panels Design Process
Although utilizing prefabricated panels can accelerate the construction schedule, additional time will be required in the design phase. It’s necessary to involve the panel engineer right from the start of the building design process, alongside the structural engineer and architect.
There are subtle factors that could significantly affect the price and simplicity of panelizing a building. For instance, in hotel design, if doors are recessed from hallways, it necessitates breaking up interior load-bearing walls and incorporating costly headers. Additional concerns arise if there’s sufficient space for routing MEPs (Mechanical, Electrical, Plumbing) through a suspended ceiling when using floor joists instead of trusses, which can readily accommodate MEP installations. In hybrid systems where steel panels are integrated into concrete, stiffness and panel tolerance assumptions need to be considered.
There is software available to aid engineers and panel manufacturers in Cold-Formed Steel (CFS) design. One such software we utilize at US Frame Factory is Strucsoft. By utilizing an existing Revit model, Strucsoft is capable of providing targeted assistance with metal stud sizing, wall panel dimensions, and the creation of detailed framing models. A detailed framing model can be observed below.
We run a software generated cut list from on our roll-formers. The roll former shapes and cuts steel coils into the studs and track of your building. Our machines exhibit a high level of sophistication in how well they align with 3D design software. Components can be intricately fashioned, with precise cuts and holes, to ensure perfect alignment between adjoining parts. For instance, flanges within a track segment can be meticulously shaped to accommodate studs, and these flanges can even be pre-drilled for easy screw installation. This manufacturing process demonstrates remarkable efficiency.
After the panels have been finished and successfully passed through a quality assurance and quality control procedure, they are either placed onto trailers or kept on-site to be delivered at a later time. Each individual panel is assigned a distinctive piece marker, which serves the purpose of designating its specific position within the structure. This step holds significance when it comes to the arrangement and removal of panels onto and from the trailers.
Wall Panel Shipment
Wall panels are efficiently stacked either vertically or horizontally as show in above. When stacking horizontally panels shouldn’t exceed 8’6 in width(the legal limit for transportation before loads become “oversized” and require extra permits). When stacking wall panels vertically bare in mind that 13’6 is the legal limit for the height of a loaded 18-wheeler. You can usually fit 10′ tall wall-panels on vertically but struggle to achieve a little more height. For this reasons we usually stack our panels horizontally and limit their width to 8’6.
On a 53′ flatbed 18-wheeler you could comfortably fit about 7,000 sf of 6″ light-gauge steel wall panels. If you’re using 3.62″ wall panels could fit about 12,000 sf.
Wall panel installation
Panels are commonly set up using cranes. To minimize crane movement duration, panels are positioned in close proximity to each other. This sequential installation of panels necessitates meticulous pre-planning.
External bypass panels, which don’t bear the structural load, will be affixed to the building’s perimeter beams. During this process, the crane system will support the panel, and either provisional or permanent anchors will be secured.
For load-bearing internal panels, they can either be hoisted into place by a crane or transported in groups to each floor level and then manually installed. Temporary bracing is required for load-bearing wall panels until the upper floor or roof is in place.