Answer: Problem 4
1.
Available materials: 1- by 6-inch S46
4- by 4-inch S4S
2.
Determine loads: Assume a live load is 50 lb/sf. The dead load is 150 lb/cf.
DL
= 150 (1/2-foot) = 75 psf
LL
= 50 lb/sf
TL
= DL + LL = 125 psf
3.
Go to Table 3-1 on page 3-6 for 1- by 6-inch sheathing for maximum concrete pressure of 125 psf.
Maximum joist spacing is 26 inches.
4.
Uniform load on the joists:
5.
Determine maximum stringer spacing using Table 3-3, page 3-9: 55 inches
6.
Calculate the uniform load on the stringer (ULSstr).
7.
Determine the maximum shore spacing.
From Table 3-3, with a uniform load of 573 lb/ft to 600 lb/ft, the spacing is 37 inches.
Evaluate the maximum shore spacing based on the shore strength. Find supported strength.
10' - 3/4" - 3 1/2" - 3 1/2" = 9' 4 1/2" to the nearest whole number is 10 feet
Allowable load according to Table 3-7 on page 3-21 for the unsupported length of 10 feet is 3,400 (using 4- by 4-
inch S4S).
Evaluate the maximum allowable load based on end-bearing area. (Since the C is unknown, use the lowest
value provided in Table 3-8 on page 3-22.)
Select the allowable load on the shore. (Compare and select the lower.)
Select the most critical spacing which would be 37 inches from using the information above.
3-31
EN5466
Previous Page
