How long can a 2×8 rafter span?
Max. Live Load 20 lbs/ft2 (956 N/m2)
|Maximum Span (ft – in)|
|Nominal Size (inches)||Rafter Spacing, Center to Center, OC (inches)||Lumber Grade|
|2 x 6||24||13′|
|2 x 8||12||21′ – 7”|
|16||19′ – 7”|
How do you calculate rafters span?
Rafter span = rafter run divided by cos °. Overhang = eaves width divided by cos ° (add dimensions for brick veneer).
How far can a 2×6 rafter span?
2-grade 2×6 joists can span up to 10 feet 9 inches from beam to beam when spaced the standard 16 inches apart with a maximum live load of 30 inches per square foot. In comparison, No. -1 grade lumber can span slightly further to 10 feet 11 inches under the same parameters.
How far can a 2×8 rafter span without support?
Span is determined by species, grade, dimensions, spacing, use, and load. A rule of thumb is 1.5 times a joist’s depth but in feet when spaced at 16” centers. In general, a 2×8 will span 1.5 x 8, so 12-feet.
How far can a 2X10 span without support?
A 2×10 beam – made up of two 2x10s nailed together – can span up to 11′ without support beneath a deck that is 4′ wide. For a more normal-sized deck, the same beam can span 8′, supporting a deck that is 8′ wide.
Can a 2×4 span 12 feet?
2×4 is suitable when the range is less than 5 feet. For example, if the span is 4 or 5 feet (max), 2×4 20kg LL trusses will fit. If you have a good stretch with the highest modulus of elasticity and the best quality and it is at 12 o.C. use, you can get $ 8.
How to determine the length of a roof rafter?
Rafter span tables – Use these tables to determine lengths, sizes and spacing of rafters based on a variety of factors such as, species, load, grade, spacing and pitch. Visit the roof framing page for more information on cutting roof rafters, and visit the roof pitch calculator for determining rafter lengths based on rise and run.
Where can I find a rafter span table?
The above spans are based on American Softwood Lumber standard sizes. For additional species of lumber, check out the Rafter Span Calculator from the American Wood Council website. ** Note: The data in the rafter span tables above were obtained from Architectural Drawing and Light Construction by Edward J. Muller.
How to determine rafter span for southern yellow pine?
Rafter Span Tables Rafter spans for Southern Yellow Pine, Douglas Fir, and Eastern Spruce Rafter span tables – Use these tables to determine lengths, sizes and spacing of rafters based on a variety of factors such as, species, load, grade, spacing and pitch.
How big should a ceiling joist and Rafter be?
Species Alaska Cedar Alaska Hemlock Alaska Spruc Size 2×4 2×6 2×8 2×10 2×12 Grade Select Structural No. 1 No. 2 No. 3 Stud Member Type Floor Joists Ceiling Joists Rafters (Sno Deflection Limit L/720 L/600 L/480 L/360 L/240 L/180