GM Pontiac Stair Width Clearance Issue
Apr 29, 2021
11
| STATEMENT OF PROBLEM The GM process team stated they wanted 36" wide clearance for all metal stairs in a design meeting. When IBI designed the stairs they made the tread 36" wide. However, the inner grab bars which project from the outer guardrail impede on that clearance (only 32" clearance). This was deemed a non-conformance by GM and required us to rework two stairs to a control balcony platform. During a design progress meeting GM stated that they desired to have a minimum 36" clearance for all stairs on the project. This was due to a past issue they experienced at another plant where they had trouble getting a stretcher down stairs. The A/E designed the stairs with a 36" width tread (except where limitations would not allow) based on the building code which requires a 36" tread and allows handrails to project into the space 3.5-4". Plans/shop drawings of the stairs did not show the inner grab bar on both sides. That was shown in enlarged details only. There was no detail showing cross-section of the stair with grab bars to understand the overall width clearance between the grab bars. The stairs all met OSHA and code requirements but because they did not meet the additional GM requirement, we were forced to modify two stairs. COURSE OF ACTION CCC was required to modify the control mezzanine stairs per the sketches in the Stair Modifications file. The result is less desireable due to aesthetic and due to there being only one grab bar. LESSON LEARNED For specific design requirements such as this, above OSHA and code and GM standards, they must be incorporated into RFPS. |
