If snow load increases from 20 psf to 30 psf, what happens to the allowable header span?

If snow load increases from 20 psf to 30 psf, what happens to the allowable header span?

• A. Remains the same
• B. Decreases
• C. Increases
• D. Becomes unlimited

Answer: (B)

Higher snow load means more weight the header must carry, which increases the bending moment the header must resist. Since the header’s strength is fixed by size and wood grade, you must reduce the span to stay within safe stress limits. Design tables and calculations show smaller maximum spans as the load goes up, so increasing snow load from 20 psf to 30 psf forces the allowable header span to decrease. The other options imply no change, more span, or unlimited span, which would ignore the stronger load and the header’s capacity limits.

Higher snow load means more weight the header must carry, which increases the bending moment the header must resist. Since the header’s strength is fixed by size and wood grade, you must reduce the span to stay within safe stress limits. Design tables and calculations show smaller maximum spans as the load goes up, so increasing snow load from 20 psf to 30 psf forces the allowable header span to decrease. The other options imply no change, more span, or unlimited span, which would ignore the stronger load and the header’s capacity limits.