Crazy and Complicated Truss Designs – Part 9

Crazy and Complicated Truss Designs – Part 9

I made two entries to the Crazy and Complicated series, but never gave any information about where I typically design my “Crazies.” My design range focuses in the continental United States, although, I have ventured into Canada and to the Caribbean, but the bulk remains in the Southeast United States and a focus in California.

Today, like my last two entries, comes another one from the Southeast with some unique situations that I hope those reading enjoy.

To give some insight, I had a situation in which I could not get a set of girders to work because of the span and shallowness, the loads coming down from a dome roof made the situation look like I was doomed to tell the customer the roof would not work. After thinking upon a solution for a slight bit of time, I came up with the following:


Lightbulb! I would thread my side support girders for the dome thru the top and bottom girders to the truss behind to alleviate some of the load placed on the top and bottom support. Lumber, like other materials can only face a fixed amount of stress before failure, so a solution for this required out of the box thinking.

The top and bottom girder below:


The side support girders (threaded):


The girders receiving the thread girder with plenty of room for a Simpson Strong-Tie THGB2 hanger:


I know there may be some thoughts as to why I did not bump up to a “Fabled 6-ply” girder instead of using 5-plies and 4-plies (totaling out to 9-plies for the main span to support the dome roof), and the answer is easy, a 6-ply truss requires trusses hanging in from both sides.


At what extent, do we finally stop trying to make something work? I know I love the mental challenge of trying to overcome the odds to deliver a solution to a problem.


The boundaries of architecture continue to push forward with the extremes of design. Don’t believe me? Just look at the architecture in Toronto, Sydney, Dubai, etc.

View Part 1 in this series here.

View Part 2 in this series here.

View Part 3 in this series here.

View Part 4 in this series here.

View Part 5 in this series here.

View Part 6 in this series here.

View Part 7 in this series here.

View Part 8 in this series here.

Stay tuned for Part 10.

Neil Laporte – Project Manager

Gould Design, Inc.

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