In a 36-foot-wide building with a snow load of 30 psf, what is the maximum span a header of 2-2x10s can support, if the dead load includes a roof, ceiling, and one clear-span floor?

In a 36-foot-wide building with a snow load of 30 psf, what is the maximum span a header of 2-2x10s can support, if the dead load includes a roof, ceiling, and one clear-span floor?

• A. 4 feet - 7 inches
• B. 4 feet - 2 inches
• C. 5 feet - 3 inches
• D. 6 feet - 1 inch

Answer: (B)

The main idea is how far a bearing header can span under the combined loads it must carry: the roof (with snow), the ceiling, and a floor above, all applied to an opening in a bearing wall. For a 2-2x10 built-up header in a bearing exterior wall, the allowable span is set by the header’s bending strength given the total uniform load from dead loads plus snow load. With a snow load of 30 psf on a 36-foot-wide building, the end-wall header must carry a substantial roof load plus the dead loads from the ceiling and the floor above. Under these conditions, the built-up header of two 2x10s reaches its capacity around a 4-foot 2-inch span. That is why the best answer is 4 ft 2 in. Spans longer than that would exceed what a 2-2x10 header can safely carry for this load case, while a shorter span would be more than enough but is not the maximum allowable. If you used a larger header (for example, 2-2x12) or added structural members, you could span longer, but for the given header size and the stated loads, 4'-2" is the limit.

The main idea is how far a bearing header can span under the combined loads it must carry: the roof (with snow), the ceiling, and a floor above, all applied to an opening in a bearing wall. For a 2-2x10 built-up header in a bearing exterior wall, the allowable span is set by the header’s bending strength given the total uniform load from dead loads plus snow load.

With a snow load of 30 psf on a 36-foot-wide building, the end-wall header must carry a substantial roof load plus the dead loads from the ceiling and the floor above. Under these conditions, the built-up header of two 2x10s reaches its capacity around a 4-foot 2-inch span. That is why the best answer is 4 ft 2 in. Spans longer than that would exceed what a 2-2x10 header can safely carry for this load case, while a shorter span would be more than enough but is not the maximum allowable.

If you used a larger header (for example, 2-2x12) or added structural members, you could span longer, but for the given header size and the stated loads, 4'-2" is the limit.