Assuring Quality Metal Walls

Quality assurance is often addressed by citing specific national testing and standards for products. In the case of metal wall panels, there are a full range of appropriate tests that have been developed and are accepted by the industry for basic sheet metal. Many of these originate from the International Building Code, ASTM International (ASTM), Underwriters Laboratory (UL), National Fire Protection Association (NFPA), American Architectural Manufacturers Association (AAMA) and others.

An Early Start on QA

Ensure metal wall panel quality assurance from a project’s start by conducting a pre-installation meeting at the job site. “A typical pre-installation meeting requires all trades/subcontractors that have any touchpoints with a system should be included in the meeting,” says Larry Owen, CSSBB, CBO, RCI, CMQ/OE, CSM, CRIS, Sr. Baldrige Examiner, performance excellence consultant, Stratela Inc., Oakbrook Terrace, Ill. “We also host special meetings with this group of contractors to review all exterior details to ferret out miscellaneous issues; verify everybody knows their scope and that the details are achievable: skin meeting or building envelope meeting.”

“It all starts with our in-house fabrication capabilities,” says Dean Jagusch, president, Wagner Roofing Co., Washington, D.C. “To ensure the quality of the metal panels during handling for any job, we not only take on the responsibility of taking field measurements, but we also control the panel fabrication within our in-house sheet metal shop. By doing so, we handle the materials from start to finish through fabrication, crating, transporting, staging and installation. [Also,] a pre-production collaborative sequence detailing work with and around other trades is critical. We work with other trades to ensure metal wall quality assurance: framing, sheathing, waterproofing, masonry, window contractors, etc. Constant communication prior to and during delivery and installation is essential.”

Examine elevation drawings and building sections, which show panels in relationship to required locations for structural support as well as exterior wall finish material. Review panel details, details showing attachment to structural support, and details showing flashing and trim that continue through to exterior finish material.

Storage, Handling, Installation

Verify upon delivery that metal panels are not damaged or deformed. They should be packaged for protection during transportation and handling. Unload, store and erect metal panels in a manner to prevent bending, warping, twisting and surface damage.

Panels should not be carried flat (panel face facing up), but vertically by the seam legs. Stack metal panels horizontally on platforms or pallets, covered with suitable weathertight and ventilated covering. Store metal panels to ensure dryness, with positive slope for water drainage. Do not store metal panels in contact with other materials that might cause staining, denting or other surface damage.

Install metal panel systems in accordance with manufacturer’s written instructions, approved shop drawings, project drawings and referenced publications. Install metal panels in orientation, sizes and locations indicated. Anchor panels and other components securely in place. Provide for thermal and structural movement. Panel damage or oil canning during installation will occur if quality control is not stressed during the project.

Fasten metal panels to supports with fasteners at each location indicated on approved shop drawings—at spacings and with fasteners recommended by manufacturer. Where metal panels come into contact with dissimilar materials, treat faces and edges in contact with dissimilar materials as recommended by metal panel manufacturer. “Verify the metal panels you are installing are compatible with adjacent materials,” Jagusch says. “You should avoid contact between dissimilar metals such as copper and aluminum to prevent electrolysis, which will ultimately lead to premature corrosion.” Attach panel flashing trim pieces to supports using recommended fasteners and joint sealers.

Inspecting Quality Assurance

During field installation, inspection is critical to ensure that the panels are installed exactly as specified and engineered with fasteners and/or clips spaced properly, laps installed as engineered, and sealants applied at the specified rates. In high wind environments, it is also critical that the metal panel installation meet the building code requirements for that region and the building owner’s insurance requirements.

Frequent and preferably daily quality assurance inspections by a knowledgeable independent quality assurance inspector will ensure the best possible installation. “We employ a job-site checklist approach to ensure our efficiencies,” Jagusch says. “Ultimately, however, it comes down to clear, constant communication between the field and our in-house fabricators. By doing so, we can label each type of panel prior to site delivery. Establishing site benchmarks goes a long way. By working with professional surveyors and verifying field measurements, we can predict and ensure that the panel production meets the specifications of the field installation.”

Inspections should be scheduled on regular phases and stages of the installation and should be documented by reports prepared by expert consultants in writing and include progress photographs showing both proper and improper installation of the system. Flexible scopes can inspect hard-to-see locations. Handheld devices are beneficial. Download the data to a database so it can be stored, retrieved and analyzed. Improper installation should be corrected (and documented) before proceeding with the next stage of the work. Owen suggests quality checks on metal panels can be done with a tape measure (fastener spacing, support spacing, etc.), digital caliper (verification of gauge) and level (installed, straight, true, level).

Getting Help with Quality

Is there a good source of information on the best ways to ensure not only quality metal panel installation but overall quality construction too? The Army Corps of Engineers has developed a very good job-site QC system that works equally well for small and large projects. It’s based on a three-phase inspection/testing process for a definable feature of work (DFOW). “Simply put, you break down your project into smaller pieces of work: DFOW,” Charles J. Kanapicki, PE, ASQ CQM/OE and CQA, senior vice president, Quality Engineering Inc., Clayton, Calif. “You uniquely identify that DFOW—typically a schedule activity ID—and mark all documentation, meeting minutes, reports, correspondence with that identifier. Prior to starting work, you verify that all prerequisites are satisfied (approvals, etc.) and that all involved in the work process know their roles and responsibilities. During work you perform the required QC activities (tests, inspections, etc.) and follow established processes for correcting nonconforming work. Upon acceptable completion of work, you file the uniquely identified QC documentation in a folder marked as such and move on. This process supports buy-in, incentive programs, culture, ways to overcome obstacles and problems. It also facilitates project closeout.”