This is the second of our three part series on specifying the visibility of connections in glulam structures. See here for information on exposed connections.
“Partially exposed” connections are those with concealed steel and exposed hardware. This is an intermediate between fully exposed and fully concealed connections. Hiding steel plates leaves more of the wood exposed to view, while bolt heads (and typically edges of steel plates) are left exposed.
Steel plates are typically hidden by cutting kerfs or sandwiching plates between pairs of glulam members. This increases the complexity of glulam fabrication, but it does not typically affect glulam sizing or number of bolts required. So the increase in cost compared to exposed connections is fairly minor.
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| Trudy Fitness Center Colgate University, Hamilton, NY |
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| Pavilion at Drumlin Farms, Lincoln, MA |
One additional consideration with partially exposed connections are beam seats. For beams with high connection forces (rule of thumb ~10,000+ lbs), it can be difficult to connect them without a steel bearing seat. Concealing the seat plate can have a significant impact on design and cost, so they are frequently left exposed even when other steel is concealed, as seen in the example below.
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| Pedestrian bridge Hartwick College, Oneonta, NY |
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| Pedestrian bridge Hartwick College, Oneonta, NY |
The project below shows a mix of exposed and partially exposed connections.
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| Full Moon Resort, Big Indian, NY |
