Annotated decking diagram. will provide more support, strength, and improved floor assembly compared to 2x4 of the same grade and species. Floor Joist Span. The 2×4’s and 2×6’s are considered to be in SPF #3/stud and the 2×8’s and 2×10’s, in SPF #1/#2. 12 in. Effective June 1, 2013 . o.c. If you use 5/4 decking, joists must be no farther apart than 16 inches. - If supporting lightweight partitions running parallel to joists, provide two additional joists under each partition. o.c. I joists installation and handling attaching railing post to a 4x8 beam and flush 2x8 joist deck unit attaching pergola posts to deck beams joists building stronger post to beam … The width is considerably more important than the thickness of a board. Your selection of decking material will determine the maximum spacing of your joists. However, when running SPF 2×6 floor joists into the floor joist calculator referenced above, you get a maximum span of 9 Feet 8 inches with a minimum bearing length of 3 inches at each end on 12” centers. Joists & Rafters. For example, 2x6 joists that are spaced 24-inches o.c. o.c. from Span tables of 2009 IRC 2x6 maximum span 9'-4" 2x8 maximum span 12'-3" 2x10 maximum span 15'-5" 2x12 maximum span 17'-10" for 16' span I'd probably go with 2x10 at 12" o.c. JOIST SIZE JOIST SPACING MAXIMUM SPAN. Summary The span of a 2x6 beam depends on several variables including the size, type, and species of lumber as well as the load. 2” X 6”. Decking made of 2x4s or 2x6s can span up to 24 inches. weight of the spa filled and 5 adults is listed at 3500#. Span Tables for Domestic Floor Joists (to BS 5268-7.1) Note: Our floor joist span tables are based on loadings given in the newer, amended version of BS 6399-1. If adding additional framing, be sure to keep all boards level and in plane across the tops. View Joist & Rafter Tables. Please select a length and a quantity and our calculator will do the rest. Wood Species: o.c. Wood Beam Calculator (American Wood Council website) Rafter and Joist Span FAQ. Span Calculator for Wood Joists and Rafters also available for the Android OS. 12 in. Select the on center spacing for the joists. which has a span of 17'-3", either that or reduce the span. Floor joist spans have been limited to a maximum of 4.2m. Maximum spans in feet-inches. Floor joist span tables for surveyors – Floor construction. o.c. o.c. Use the Joist Span table to find the acceptable joist sizes for a 12’ span, 2x8s at 12” O.C., 2x10s at 16” O.C. 24 in. Please note that when deck joists are cantilevered they should not extend further than one-fourth of the “actual, adjacent joist span” according to IRC … 2 grade, there is a method that can be used for estimating beam spans for a preliminary design. o.c. A triple 2x6 beam over a span of 10' feet should be more than sufficient for normal deck loads. Ceiling Joist Span. CASE II SOLUTION: The decking span you choose will affect the feel and potentially the safety of your deck. Joist Span Calculator. At 16 inch spacing, 15 feet 2 inches and 13 feet 3 inches at 24 inch spacing. o.c. For example, a joist made from doubled 2 x 6s can span a distance about 25 percent more than a single 2 x 6, but a 2 x 12 can span about 80 percent more than a 2 x 6, even though it has the same amount of wood as a doubled 2 x 6. The minimum bearing length is 1 ½”, spans values in bold indicate that web stiffeners are required at the OSB end panel. also available for the Android OS. Let's expand our house beyond that 17'2" span capability to 24 feet wide. Refer to the Decking Span Table to determine what is the maximum distance that your chosen decking can span between joists. with a deflection of L/360 you could expect the following deflection = (16'x12" per ft)/360 = 0.53" If I sister a 2x8 to each 2x6, meaning that the bottoms of the joists line up but the top of the 2x8 is approximately 2 inches above the top of the 2x6…is there a span table for such a situation, or any rule of thumb for estimating strength as per code? the deck is typical construction. Again, it's important to know your local codes. 24 in. Use the Beam Size table and find the 8’ post spacing column. Maximum Spans. 10’ - 0”. 16”“ 9’- 1”. Size S. Spacing In. The widest span in the floor joist span table in Part 2 of this tutorial module showed that floor joists can span 17'2" if they are 2 X 12s spaced 12" o.c. 2x6 or 2x8 for deck joist. For example, a 2 x 12 joist placed 16” OC. o.c. Spaced at 12 inches, the joist may only span 16 feet 8 inches. Treated & Graded Decking Joist (6" x 2") Stress graded to C16 this timber is well suited to all structural applications. The lowest is a plain ceiling joist with no storage (10 pounds per square foot). 2×6 joists 24″ oc, spanning 10′. (on center). This 6" x 2" is a perfect way to start your new Deck, strong and easy to work with you won't need a professional! This a rough guideline. With a 12’ deck span, the beam may be either two 2x8s or two 2x10s, depending on wood used. Read on and learn a little bit about what affects your decking's strength - like material and joist spacing.