Project: 3253 Christman Norcon Perennial Corktown Apartments

STATEMENT OF PROBLEM:

The Perennial Corktown Apartments is primarily a concrete structure (cast in place). CCC had structural steel and miscellaneous steel spread out throughout the building. Many of our elevations were determined by measurements off of the concrete, however, in two particular areas, which were to hold the storefront glazing, we had very specific tolerances to work within. Due to some benchmark errors and a misunderstanding of the detail, our Ironworker Foreman and crew set our steel at an incorrect measurement from the lower sill. The detail actual called out for this opening as the minimum opening size. Due to our error and the time at which it was identified by the GC and other trades, the lower sill had to be cut down and our lower steel had to be reworked. CCC was backcharged for this error. The shop drawings were correct but the installed measurement from sill was incorrect. 

ROOT CAUSE:

CCC should have requested or performed a survey of the opening prior to installing our steel to know what our opening tolerances were. We also should have confirmed our opening tolerances with the GC and other trades to avoid the rework that was required.  

COURSE OF ACTION:

CCC had to remove the lower sill angle so that the lower stone could be cut down to create a larger opening for the glazier. The costs of the rework of the stone and the additional changes to the fabricated storefront system were passed on to CCC for a total cost of $65K. 

LESSON FOR FUTURE PROJECTS:

This sequence of decisions and events put a spotlight on the importance of details and the difference between elevations that need to be met, or tolerances that need to be maintained.  Notes need to be prominent on the details and shop drawings.