What Is a Mill Cert?
Robert Grupe / May 2020
Q: In cold-formed steel framing, what are mill certs, and do I need to obtain them for my projects?
A: A mill cert is documentation provided by the manufacturer of the steel material, the steel mill, that includes information relative to the composition of the steel itself. From a contractor perspective, there is nothing written into the model codes for a cert to be provided as part of either the permit or inspection process which would include the submittal phase.
Recently, Pat Ford, P.E., technical director for the Steel Framing Industry Association, wrote a paper on the subject, which is available upon request from the SFIA. The term itself can be seen as an industry colloquialism regarding what is more accurately termed a mill test report, which can be certified. The certified report states that the specific material in question meets recognized standards such as ASTM.
In his report and quoted below, Ford states that the mill test report should contain the following data:
- Basic information such as name of the material manufacturer, material size, weight, material identification and grade, i.e., ASTM A106 Gr 60, ASTM A1003, Grade 33, etc.
- Material heat number
- Coating thickness
- Chemical composition analysis test results
- Mechanical test results
The above list is seen as a minimum number of listed properties. More information, which is common in the cold-formed steel industry, may be included.
The report itself might be part of a quality assurance program of the manufacturer of the end-use product, that is the fabricator of cold-formed steel framing. Further, associations like the SFIA may require the mill test report as a component in their code compliance program. The SFIA program provides third-party oversight on the materials used and the final end-use product. Even with the mill test report in hand, the third-party audit requires testing as to material properties such as type of steel, tensile strength, corrosion resistant coating and material thickness.
Code compliance for steel according to the International Building Code (2018) is specified in Chapter 22, Steel. Cold-formed steel is referenced in Section 2211, Cold-Formed Steel Light Frame Construction. For structural applications, the design and installation must meet the American Iron and Steel Institute’s AISI S240, while for nonstructural applications the referenced standard is AISI S220. Cold-formed steel framing is cross-referenced in Section 2506, which is on gypsum board and gypsum panel product materials. The same two AISI standards are therein referenced.
The code appears to be silent on cold-formed steel accessories. The notable exception is found in Section 2506 where gypsum board accessories are referenced. These products, typically beads and trims, can either be metallic or non-metallic and have specific material references that must be met. However, at the association level, there may be code-compliant programs that assure steel framing structural accessories are acceptable to the building code. SFIA has a Connector Code Compliance Program that all framing product member companies must abide by. This program includes steel straps, ties and angles.
The IBC does not require a contractor to provide mill certs to show compliance. This pertains to structural, nonstructural, and even their essential accessories. Interpretation and enforcement of the building code is the right and responsibility of the authority having jurisdiction over a given project. The AHJ may, in fact, require that the contractor provide documentation such as mill certs for a project. This can become problematic when mill certs are not available to the fabricator to provide the contractor, meaning not every coil of steel coming into a stud fabricator facility has an associated mill cert. That doesn’t imply a lower quality of material, it can be simply the circuitous route that the coil takes before it arrives in the fabricator’s facility. The proof of quality comes in the actual third-party testing through a code compliance program that occurs at the facility where the framing is produced. In this instance, it becomes exceedingly difficult after the fact to obtain the mill cert.
The need for a third-party compliance program really becomes important. Code compliance is assured through third-party audits and test verification. This effectively eliminates the need for the mill certs beyond the fabricating facility. The mill cert becomes redundant when the product in question is certified by a third party as meeting the requirements of the building code.
In summary, a mill cert is a document provided to the stud fabricator that certifies the material shipped meets the requirements as specified by the fabricator. It may be required between the steel mill and the fabricator, but there is no written requirement within the IBC for the mill cert to be utilized at a job site. It is not intended to be utilized beyond the fabricator. Code compliance programs offered by associations like SFIA provide the needed certification to show compliance to the building codes. This is true for both structural and nonstructural framing products, and includes ancillary accessories. A contractor should be aware of the local code requirements for a given project. If there is an AHJ who in the past required mill certs, the contractor should be proactive. An attempt should be made to negotiate the perceived necessity of requiring a mill cert.
Robert Grupe is AWCI’s director of technical services. Send your questions to email@example.com, or call him directly at (703) 538.1611.