For residential living-area floor framing eligible for the conventional provisions of 2021 IBC Section 2308, use Table 2308.4.2.1(2) with 40 psf live load and an L/360 deflection limit. No. 2 Douglas Fir-Larch 2x10 joists are spaced 16 inches on center, but the dead load is 20 psf. What is the tabulated maximum span?
- A11 feet 6 inches
- B15 feet 5 inches
- 14 feet 1 inch
- D16 feet 3 inches
Where to look it up
https://core-docs.s3.amazonaws.com/documents/asset/uploaded_file/3836/Lennox/3042180/2021_International_Building_Code.pdf
Why C is correct
For the specified row, the 20-psf-dead-load 2x10 column gives 14 feet 1 inch. The 15-foot-5-inch value is for 10 psf dead load and cannot be used for this case. Source: 2021 IBC 2308.4.2.1 and Table 2308.4.2.1(2), p. 23-38; https://core-docs.s3.amazonaws.com/documents/asset/uploaded_file/3836/Lennox/3042180/2021_International_Building_Code.pdf