The project is in the stages of steel erection and the vertical columns are pretty much in place. As the steel members meet with other steel members or portions of the building, it’s all about making the connections; how the members fasten to one another. The horizontal steel is now going in and the first order of business is installing the floor beams for the Gallery space. In the sketch above, there are workmen that are part of the steel erection team and in the background is the familiar sign for the local business serving morning sweet deights; the Donut Shop. The floor beams are installed and the metal decking is being put into place over the beams. The elevated concrete slab will be poured over the metal deck and will become the floor surface for the Gallery.
The area below the Gallery is the mechanical crawl space that houses a variety of equipment that includes the gray water system and the air distribution ducts that supply conditioned air to the Gallery through floor registers. This crawl space has poured-in-place concrete walls on all sides. So, to fit the beams between the poured walls you’re hoping the placement of the walls and the space between their faces if pretty accurate. But remember, we are dealing with constructing a full scale version of the drawings and there needs to be allowances for field tolerances as the location of the walls may vary slightly. If the beams don’t fit, it’s like being between a rock and a hard place; literally.
FSB’s structural engineers take these conditions into account when designing the beams and connections in confined areas like the crawl space. Ways to allow for field variances are to include slotted holes in plates for bolted connections and having loose tabs that can be welded to wall plates embedded in the concrete. But even with all this, Tab A does not always fit neatly into Tab B which is where you rely on skilled crews to work through it all and have it come out looking good. As these Gallery floor beams and their respective connections were the first test of workmanship, all eyes were on the finished product.
You can see we had some good looking connections and some not so good looking connections. This mechanical crawl space was a good location to work on the finished product as it would not be seen by the public. So yes, we had to work some things out with the contractor and steel erectors. FSB’s primary focus was to make sure that regardless of how they might look, the connections were structurally sound. It also gave us an opportunity to work through the connections with the contractor so as we moved upward into more public spaces the connections would achieve a level of quality acceptable to all parties.
Once again, we see that putting the building together is a matter of teamwork between all of the team members as we are reminded that construction is not an exact science. None the less, we worked through it all, set common expectations for the remaining work and were on the same page moving forward.
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Design Matters 