As with much of the building industry, wall framing is continually evolving. Our firm, Steven Baczek Architect, keeps an open mind when it comes to new products. For a current residential project, we are using the Tstud as a main component for the exterior wall framing. The house’s small size, simple form, and straightforward framing plan created the perfect proving ground to use the Tstud for the first time. While dimensionally similar to the common 2×6 solid stud, the Tstud provides a substantial reduction in thermal bridging, and has three times the strength a conventional 2×6 stud. Coupled with insulating exterior sheathing (R-9) and blown cavity insulation (R-29), it creates the basis for an exceptionally efficient wall frame with a whole-wall R-value of 30. The benefit of the Tstud is the cavity insulation between the stud chords, which does not exist in solid-stud framing. While the insulating sheathing does provide a thermal break, we chose to use the Tstud to further enhance the thermal break of the wall assembly in its entirety.
Because this was our first time using the product, it was essential to thoroughly consider and review a few typical details. Both an exterior wall rough-framing plan and an elevation plan were drawn to determine the specific areas of interest. As illustrated, the Tstud has different widths for the two chords. However, the dimensions remain the same—one is oriented 90° in relation to the other. The result is that one face yields a 1-1/2-in.-wide surface (the spline), while the opposing face has a 2-1/2-in. surface (the flange). Following conversations with the framing contractor, we decided to use the flange as the exterior face of the framed wall. That size face created a better nailing surface for the exterior sheathing. The wall board subcontractor then used the spline as a recognizable dimension.
One of the details we reviewed was a stud-framed outside corner—typically called a California Corner. We used two Tstuds (detail A) to create a “Missouri Corner,” a nod to the project location. Notice the orientation of the outside flanges to avoid conflict in the framed corner. A 1×4 drywall backer was used as a drywall catch on the open framed side of the corner. (This could be substituted with a drywall clip to further eliminate wood in the exterior wall.)
Detail B shows a cross section where an interior partition wall will intersect the exterior wall. The 2×4 ladder blocking was installed laterally between two Tstuds and located roughly 24 in. o.c. vertically. This can be seen in the exterior rough-framing elevation drawing.
Given we would be using blown-in insulation in the wall cavity, and the fact that the Tstud is an open web, we had to address the window rough openings, which would allow the blown insulation to escape. The solution was to integrate a standard 2×6 jack stud for a lateral cavity closure (detail C2). The adjacent Tstud serves as the king stud for the rough frame of the window opening (see elevation drawing).
In detail C1, you can see the adjacent king stud continues to the bottom plate on one side of the jack stud, while the cripple Tstud supports the rough sill on the opposing side of the 2×6 jack stud.
In terms of code, the IRC considers the 2×6 Tstud a direct substitute for the common 2×6 solid stud, providing the Tstud is vertically oriented. All code requirements that apply to typical framing members apply to the 2×6 Tstud, which can be cut at any length. Although it is recommended to avoid cutting any dowels, a lateral cut to one dowel is acceptable; two or more cut dowels are not.
In summary, we found the Tstud to be easily integrated into the project—its enhancement of the assembly far outweighs the little to no disruption in the framing construction process. We firmly recommend it to others in the industry, and are apt to use it in future projects.
-Alexandra Baczek is an associate at Steven Baczek Architect. She is a graduate with a Master of Architecture from Roger Williams University. Illustrations by the author.