What’s Ahead for Steel Frame Construction
It was not long ago that grocery store attendants asked “paper or plastic?” as you checked out. It was an even shorter time before that when paper was the only option. Now, if you wish to have your groceries bagged in paper, you must request it.
Technological advances of the properties of plastic and its ability to make superior products helped bring it to this market. Plastic bags are stronger, lighter, recycled, recyclable and cheaper. When the consumer had the choice, a vast majority chose the better product. Now, even with that choice limited by economics and consumer preference, the technology of plastic allowed for not only its entry in this market, but its overwhelming market share.
Steel or wood?The technology of steel, its properties and the products it makes, have helped to widen its uses in several markets, most notably, construction. With rapid acceptance and regular use in commercial market sectors, light gauge steel framing has great potential for growth in residential markets as well. But technology must do more to advance the option of steel frame products in the eyes of the builder, so that the choice of steel or wood eventually just goes away. In that case, steel is not only the better product, it is also cheaper, easier to use, and more accessible than its counterpart.
Technological advances for steel framing will affect all construction markets, commercial, light commercial and residential. But managing the required research and development projects, implementing results into ANSI-accredited documents followed by building codes and instructing design professionals, builders, general contractors, and code officials of the newest technology available takes a strong leader in the industry.
The Steel Framing Alliance, with strategic partners including American Iron and Steel Institute’s Committee on Framing Standards, National Association of Home Builders Research Center, U.S. Department of Housing and Urban Development, Light Gauge Steel Engineers Association and several other research and educational institutions are offering such leadership and contractors can utilize this resource.
History of the AllianceThe Steel Framing Alliance has undergone serious and substantial organizational changes since the beginning of this year. Formerly known as the North American Steel Framing Alliance, it has opened membership to the entire construction industry, folded in commercial market endeavors from the AISI’s Commercial Framing Task Force, and invited global companies to join. To do all this, the organization restructured to meet the demands of the construction industry.
The Alliance has developed working member teams to help steer the its efforts in commercial, education, marketing, membership, and technology. An Operating Team oversees all strategic direction, and the Research Team oversees research and development activities, fed by market requirements proposed through the Technology Team. Members participating in a team(s) truly have a voice in the direction of their Alliance, managed by team leaders who have the expertise and skills to build consensus and produce rapid results.
So what does this mean to the contractors and what should contractors expect to see in the future for steel framing? First, it brings to a contractor the chance to play a part of the future through membership in the alliance. Second, it provides the opportunity to hear what is coming out of research and development programs to help anticipate how the future of construction will look. Through membership in the Alliance, contractors gain special access to innovative products and building methods that may help the bottom line, or that of the customer. The Alliance is working to be a gateway to the future of construction technology as technology is what will bring better products, greater efficiencies, and more savings to the process of building a home, a school, a grocery store, even a new office building.
Research and developmentThere are more than 13 R&D projects now underway or nearing completion, representing more than $1 million worth of research jointly progressing with the help of both government and private industry. A few of the most recent projects are summarized here.
Thermal Steel Studs: This project has been funded mostly by the U.S. Department of Energy (DOE). A slit-web steel stud has been developed and initial testing showed an increase in the overall wall R-value when the slit-web stud is used. Several wall assemblies have been structurally and thermally tested; more testing is being done on wall studs with sheet steel sheathing. Oak Ridge National Laboratory, project partner, has issued an initial report.
Fire and Acoustic Tests for Residential Construction: A report summarizing the existing fire and acoustic details used in steel-framed homes has been prepared and is under review. The steering committee has been assembled to review the report and make recommendations for steel assemblies requiring further testing. Selected assemblies will be tested for fire and sound transmission.
Steel Shearwalls: Steel shearwalls with double layers of OSB and varied screw patterns, shearwalls with gypsum board, and shearwalls with sheet steel are being tested.
Structural Components: Single L-shaped headers are being tested for small openings. Currently double L-shaped headers are increasingly used in steel construction. A final report will also be issued for single L-shaped headers.
Fire and Acoustic Tests for Commercial Construction: Two sets of tests on walls and two sets of tests on floors have been conducted. The wall report and first-floor test have been completed. Final results will be reported.
ICF-to-Steel Hybrid Connections: ICF-to-steel connection details have been gathered and are being assembled into one document. New details that cannot be engineered are being identified and will be tested to establish their strength. A final document summarizing test results and details will be prepared.
Galvanized Steel Framing for Residential Buildings: A five-year research program is underway investigating the corrosion performance of galvanized steel-framing components in residential construction. The program measures actual corrosion rates of steel framing members and correlates them to environmental conditions. Four sites were selected: Miami, Leonardtown, Md., Long Beach Island, N.J., and Hamilton, Ontario, Canada. From both year-one and year-three samples collected, no measurable corrosion was detected.
Corrosion of Galvanized Fasteners: Tensile tests of galvanized screws into 54-mil sheet steel is being tested under three conditions: 1) new connections; 2) connections exposed to harsh environmental conditions in Hawaii for two years; and 3) connections tested after undergoing accelerated testing in lab simulations (corrosion chamber cyclic testing). A final report will be issued as well as a guide for recommended fastener use.
New ANSI-accredited StandardsFurther advancements have been made recently that result in a set of four American National Standards Institute-approved standards for cold-formed steel, published in July by the AISI Committee on Framing Standards. The ANSI is a private, non-profit organization that administers and coordinates the U.S. voluntary standardization and conformity assessment system for standards developers. The COFS is an ANSI-accredited, consensus standards body that develops, maintains, and improves AISI design and installation standards with the purpose of eliminating regulatory barriers and increasing the reliability and cost competitiveness of cold-formed steel framing.
The ANSI standards include: Standard for Cold-Formed Steel Framing; General Provisions (GP 2001); Prescriptive for One and Two Family Dwellings (PM 2001); Truss Design (TRUSS 2001), and; Header Design (HEADER 2001).
The Standard for Cold-Formed Steel Framing—General Provisions contains general requirements for residential and commercial construction, prescriptive and engineered design. Examples include member identification and labeling through basic tolerances such as in-line framing. It is the base standard from which the other three framing standards are derived. The Standard for Cold-Formed Steel Framing – Prescriptive Method for One and Two Family Dwellings is an extensively updated version of previous CABO and IRC building code submittals as well as the Prescriptive Method, 2000 Edition. The newly revised Prescriptive Method incorporates all of the latest cost-saving developments such as the L-Header, ASCE 7-98, LRFD design, and an efficient design procedure for built-up headers.
The Standard for Cold-Formed Steel Framing—Truss Design provides technical information and specification on cold-formed steel truss construction applying to the design, quality assurance, installation, and testing of steel trusses.
Lastly, the Standard for Cold-Formed Steel Framing—Header Design is a two-part standard that offers design professionals the tools they need to design efficient built-up and L-shaped headers.
The publication of these standards is a culmination of several years of hard work by volunteers from the steel-framing industry. They provide the latest technology for designing, specifying, and constructing steel framed residential and light commercial buildings, reflecting the construction market’s growing desire to innovate building methods with new materials. Steel Framing Alliance members receive substantial discounts on these and other R&D publications.
The Next Step: code approval: The Alliance recently received word from the International Building Code officials at the International Code Council that its proposal to add a steel perforated shear wall design technique was approved. This proposal also permits the use of double-sided shear walls of plywood, OSB or sheet metal shear (wallboard already permitted) and single-sided wallboard shear walls. These code-approved techniques help mirror steel frame construction with that of wood, allowing a more even playing field for steel. W&C