Seeing so many flat roofs early this year made me wonder if the future of truss building will be flat. During the January SBCA Phoenix Open Quarterly Meetings, some of us saw Truss Fab Components’ yard loaded with flat trusses, and others saw the flat roof lines of Frank Lloyd Wright’s Taliesin West. The following week at the IBS Las Vegas Show, many of us also saw the National Homebuilders’ vision of the future at their annual exhibit of The New American Home (TNAH). While the roof of last year’s TNAH was only half-flat, this year’s roof was entirely flat, like its neighbors, and like several TNAH homes from previous years (see also The Last Word from March 2022, “The New American Home”).
These new Las Vegas homes actually echo century-old designs, not only Taliesin but also Wright’s other work. [For all photos, See PDF or View in Full Issue.] Note the long stretches of white-banded cantilevers in both his Falling Water and the 2023 TNAH. While today most CMs rarely supply trusses to custom houses like these, they do increasingly supply scaled down flat truss packages for detached single family, town homes, and condos. Often, they deliver them into communities with conventionally pitched roofs, as was the case with the 2022 TNAH. As the aesthetics of these houses become more mainstream, the appeal of steeply pitched roofs is bound to diminish. Although this “look” is centuries old, it may become unsustainable due to increased energy consumption, material costs, and maintenance concerns. What does it cost to replace the old church roof shown here or to work safely on the steep slopes of these new custom homes?
To build flat trusses efficiently requires specialized equipment. Even if their production volume is insufficient, such equipment may be fully utilized by including shorter span trusses, girders, and jacks. Joe Hikel at Shelter Systems uses two 40’ Auto 8 platten presses, back-to-back, upon which truss builders can stack and band these trusses as they come off the table, avoiding double handling. Tom Mabry at Innovative Construction Group expedites production with a specially built Wizard PDS-J table and large display screens (a setup shown in MiTek’s booth at BCMC 2022 too). This system is simply a modern adaptation of wood table systems in which plates are nailed onto the top side of the truss and it is flipped onto plastic top tables for affixing of plates on the opposite face. This assures more accurate plate placement which is especially critical for the underside plating of flat girders. Then these trusses are pushed onto narrower exit rollers to be conveyed to the final press (without use of a roller gantry). This method of conveyance is especially advantageous for longer spans and longer runs of flat trusses.
While the majority of single family detached housing may always favor sloping roof trusses, the bulk of high density housing is moving increasingly to flat trusses. Adding to this volume are the flat roof systems on commercial retail or office structures. These trends are a very positive development for the growth and stability of the wood component industry as wood competes with steel and concrete for market share.