Q&A: What you should know about specifying steel framing
Cold-formed steel has been one of the most widely used building materials in commercial construction for nearly a century, commonly being specified in a wide range of framing applications, including loadbearing, non-loadbearing, and floor joists. The material’s performance qualities have been well-documented over the years, and these characteristics continue to expand as manufacturers invest in the research, equipment, and manufacturing processes to keep cold-formed steel design at the forefront of cutting-edge building construction techniques.
However, to realize the advantages of these attributes, architects, specifiers, and designers need to be aware of the current building codes, performance criteria, and design requirements shaping steel stud construction. For an up-to-the-minute look into the industry, Janine Dallies, CSI, CDT, LEED Green Associate, manager of ClarkDietrich Building Systems’ Architectural Sales Group, discusses the latest on what you should know when specifying cold-formed steel framing for your next project.
1. What considerations should specifiers be aware of when thinking about working with cold-formed steel?
For exterior framing, there are a couple of issues impacting the specification of the steel framing members selected for this application. Recently, there has been a lot of confusion in the industry about code compliance requirements for cold-formed structural studs set forth per ASTM C955, Standard Specification for Cold-formed Steel Structural Framing Members, as it relates to Paragraph 4.4 for protective coatings and Table 1. The table lists two coating designators, CP60 and CP90, which permit any of the listed metallic coatings. More specifically, ASTM C955 states that structural studs must have a minimum protective coating in accordance with Table 1—CP 60 is the minimum to be code-compliant. This designator permits the use of G60, A60, AZ50, or GF30 coatings. It is important to note this nomenclature when specifying structural steel framing, so as not to confuse the coating designator for an actual coating of any type.
For nonstructural steel framing members for interior framing, the 2015 International Building Code (IBC) lists ASTM C645, Standard Specification for Nonstructural Steel Framing Members, as its governing industry standard. ASTM C645 addresses four key attributes in a series of sections, including Materials and Manufacture, Dimensions and Permissible Variations, Performance Requirements, and Marking and Identification Requirements (now addressed in American Iron and Steel Institute [AISI] S220, North American Standard for Cold-formed Steel Framing–Nonstructural Members).
2. What are some of the changes we can expect to see in the building code as it relates to cold-formed steel?
There are a couple of changes that could be coming to the 2018 International Building Code that specifiers should be aware of. AISI has merged six separate cold-formed steel framing standards into a new standard—the 2015 edition of AISI S240, North American Standard for Cold-formed Steel Structural Framing.
Regarding nonstructural steel framing, the next thing to watch for is the emergence of AISI S220. This standard has been adopted by the 2015 IBC and will eventually replace ASTM C645 as the universal industry standard for the specification of nonstructural steel framing. Until then, the guidelines and requirements of ASTM C645 and C754, Standard Specification for Installation of Steel Framing Members to Receive Screw-attached Gypsum Panel Products, should be followed.
3. What trends are you seeing related to specifications?
One trend we are seeing is the recycling of project specifications. In fact, a recently released survey by the American Institute of Architects (AIA), The Architect’s Journey to Specification, notes that 75 percent of architects reuse specs from previous projects. While this creates obvious time efficiencies, it can also cause specs to become outdated and full of errors. For example, specifiers should note that Section 05 40 00–Cold-formed Metal Framing now includes an article for interior non-loadbearing walls for framing that exceeds the height limitations of standard nonstructural metal framing. This is a relatively new change, as this application was previously included in Section 09 22 16–Nonstructural Metal Framing. Staying aware of these changes can go a long way in developing clear, correct, concise, and complete project specifications.
It is also important to note that many of the widely used architectural specification software systems update their databases as infrequently as once a year, and even then, the user must accept these updates in some cases. These ‘technology gaps’ can pose huge issues, so taking advantage of services like manufacturer specification reviews could prove beneficial to specifiers.
4. How is technology changing product specifications?
Much like every aspect of our lives, technology is having an impact on project specifications. Digital tools like online product submittals that include current and accurate product evaluation data and test results are reducing some of the hassles traditionally related to the paper trail of specifications. Growing concurrently with the proliferation of product documentation needed to meet the various sustainable initiatives is the number of online, cloud-based providers that serve as repositories for all types of product disclosures. For instance, architecture/engineering/construction (AEC) professionals can now use online platforms like the Sustainable Minds Transparency Catalog and Mindful Materials to locate transparency information such as Environmental Product Declarations (EPDs) and Health Product Declarations (HPDs), all from a single website.
All information listed in this section was submitted by ClarkDietrich.
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