Looking for innovative flooring techniques? Check out the APA’s newest video which shows a premium I-joist floor assembly that uses 7/8 Performance Category OSB glued and nailed to 14-inch-deep I-joists that are spaced at 24 inches on center. This new flooring assembly results in a stiff floor with a quality feel.
Of course 7/8 floor sheathing is usually rated for 32-inch on-center joist spacing. But when you space the I-joists 24 inches on center, you get a premium floor that can actually save you money and time.
From the APA: “Even though the thicker sheathing and deeper I-joists cost a bit more, those costs are offset by the materials savings, so you get a premium floor system installed for about the same cost as more traditional construction. Depending on the performance expectations of the floor and the loads that must be accounted for in the design, the number of joists can be decreased by more than 1/3 when compared to the typical lumber floor system.”
Better still, this new flooring technique allows you to save in the following ways:
- 1/3 less floor construction adhesive
- 1/3 less joists to install
- 1/3 less floor sheathing fasteners
- 1/3 fewer fasteners and hangers used on the joists
- 1/3 fewer holes to drill for running ductwork, electrical and plumbing
Because the joists are generously spaced, there is enough room for ductwork and plumbing. This helps to keep ductwork and plumbing inside the conditioned space and negates the need for exterior chase ways which would require additional insulation.
This premium I-joist floor assembly uses deeper, stiffer and stronger I-joists and thicker floor sheathing. With this floor system, builders use 7/8 Performance Category OSB or plywood glued and nailed to 14-inch-deep I-joists that are spaced at 24 inches on center.