Observation From The Field: Fixing Pipe Support Issues on Metal Roof

Benchmark Service: Construction Phase Services

Issue: Fire suppression pipe supports were affecting the standing seam metal roof (SSMR) panel system on a facility in Guanajuato, Mexico. On the first day at the project, while examining previously installed panels, many were noticed with pronounced dents from the bottom side of the panels. Several had been marked. Another QA consultant hired by the construction management company explained that he had marked the panels for replacement. He had no idea how the damage had occurred. During the review of the installed panels, the reason for the panel damage became apparent at the open bar joists (lightweight steel trusses used in building construction to support roofs). The fire suppression pipes were attached to the top of the bar joists with a steel band hanger (hardware used to support and secure pipes, ducts, and other cylindrical objects to a structural element) with a closure bracket that was at a higher elevation than the top of the bar joists. After presenting photos and having conversations, a meeting was scheduled to discuss the issue. The owner and all contractors involved were part of the meeting.

Solution: The mechanical contractor installing the pipes stated that it needed to be at the elevation, per local codes. The Benchmark consultant explained that the new metal panels would thermally contract and expand daily, raising concerns about potential wear through the 24 gauge steel over time. After reviewing the building dimensions, the consultant determined that the pipe would be attached at over 10,000 locations. The following day, the mechanical contractor presented three different materials to be used as covers for the closure bracket. Benchmark advised that any of the three would work for a short period of time, but probably not for the 10-year warranty period or longer. The mechanical contractor located a different attachment hanger, which was reviewed by all, including structural engineering for approval. The new brackets were installed to replace all previously installed insufficient brackets, as well as for the remainder of the building.

Possible Impact: Without replacing the hanger brackets, severe damage was a potential to the new standing seam metal roof system. The old hanger brackets could have caused the panels to warp or buckle due to the inability to expand and contract properly. This could have led to leaks, structural integrity issues, and increased maintenance costs. Additionally, the aesthetic appearance of the roof could have been compromised, potentially decreasing the overall value of the property. The new hanger brackets will allow for the panels to expand and contract on a smooth plane, as designed, thereby preventing these potential issues.