Under Pressure: Repair Work Can be Like Starting from Scratch

By Craig Carson

I’m at my desk, staring at my monitor, wondering where my time has gone. We’ve been asked to bid on some nice projects, and it’s difficult to decide which ones we can pursue and which ones we have to turn away. Plus, we’re planning to move into another building, which involves staging material, installing equipment, and running power. We also have to lay out the offices and want to incorporate some new ideas to give it a classy look for our
suppliers, guests, and, most importantly, our team members. I feel like a kid in a candy store and love all the pressure.

Leaky Situations

One of the projects we’re doing is repairing a leaky curtainwall that another glazier installed in 2008. We have to remove the existing glazing to install new gaskets and end dams. The quality of the work we’re looking at is embarrassing. The pressure plate was not screwed tightly to the mullion because the screws used the wrong point and would not set properly. As a result, the pressure plate did not apply the correct pressure on the gaskets
to seal against the glass properly.

The end dams were installed but not set in sealant; a skim coat was smeared around with the tip of the caulking tube. The horizontal to vertical joints were never buttered, and the interior stop (this was originally an inside set system with an applied exterior pressure plate) was not sealed.

Looking for Answers

We were told that the system leaked from the beginning of the building’s occupancy, but the problems could never be solved. Really? A consultant was brought in to review the curtainwall problems and make suggestions. One of the tests was a standard AAMA 501.2 Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems. When performing the test, water did appear
in the interior of the building. However, it was also flowing under the horizontal cover, and the glass before those areas were tested. That’s a big problem.

Our job is to repair these areas by replacing the gaskets, installing new end dams, sealing the horizontal to vertical joints, and the interior stop. Currently, we’re fixing the interior stop to make it exterior glazed. When reattaching the pressure plates, we’re replacing all of the fasteners with the proper sized screws, placing them at 6-inch centers, and following the manufacturer’s torque recommendations.

Whenever you start something like this, it’s good to check the system by testing it for the repairs you’ve made. Typically, we would do this at the 10% completed level, but this project has narrow, vertical bays, four to five bays wide. So, we decided to wait until we reached 20% of the test area before testing. Fortunately for the owner and us, the repairs have worked. Once again, the devil is in the details.

Craig Carson is the vice president and general manager of 8G Solutions in Denver.

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