support bending, shear and deflection resulted from the loads shown in (a, b). T
ID: 1714667 • Letter: S
Question
support bending, shear and deflection resulted from the loads shown in (a, b). The joist will be used in dry condition with normal load-duration and adequate bracing and end supports. The stringer will be used in dry condition with short load-duration and adequate bracing and end supports. The available wood species is Southern Pine grade No. 2. 2- Determine the minimum-sizes of joist in (a) and stringer in (b) required to a) 400 lb./ft. 4 ft. 4 ft. b) 800lb. 800lb. 800lb. 800lb 800lb. 800lb. 2ft. 2ft. 6 ft. 6 ft. 6 ft.Explanation / Answer
ANSWER a)
Joist span tables - Use these tables to determine lengths, sizes and spacing of ceiling joists. The highlighted cell (below) shows that a 2" x 4" Southern Yellow Pine joist, with a grade of #2, and spaced 24" apart can have a maximum span of 5feet to 9 feet - We have Only 4 feet of each span.
The above spans are based on American Softwood Lumber standard sizes.
ANSWER b)
From the above table we can get the size of joist 2"x8" with 16" space Oc.
Also many composite materials require 12"on center stringers spacing to support.
Nominal Size Spacing (o.c.) Species and Grade of Lumber ( No Attic Storage - Drywall Ceiling) Southern Yellow Pine Southern Yellow Pine Douglas Fir Eastern Spruce #1 grade (kiln dried) #2 grade #2 grade Structural 2" x 4" 12 13-2 11-10 12-8 11-7 16 11-11 10-9 11-6 10-6 24 10-5 9-5 9-11 9-2 2" x 6" 12 20-8 18-8 19-11 18-2 16 18-9 16-11 18-1 16-6 24 16-4 14-2 15-7 14-5 2" x 8" 12 27-2 24-7 26-2 24-0 16 24-8 22-4 23-10 21-9 24 21-7 18-8 20-6 19-0 2" x 10" 12 34-8 31-4 32-9 30-7 16 31-6 28-6 29-9 27-9 24 27-6 23-1 26-0 24-3Related Questions
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