Decking If you choose pressure-treated lumber, you'll have a choice between 5 4 x 6 decking (1x5-1 2 actual size) or 2" material (typically 2x4 through 2x8, all 1-1 2" thick). The size and species of the decking you choose will determine the spacing between your joists. Recommended spacing for common decking boards is
Bearers are the timbers that are attached to the stumps or posts that support the deck and Joists are the timbers that are attached across the bearers to which the decking boards are in turn attached. In addition, the concept of single and continuous span must be explained. A bearer that is considered to be
sible since railings double as bench backs. The seat slats are 1x2 boards set on edge and spaced 1⁄2 inch apart. Bench supports extend from the railings'. 2x6 posts which are, in turn, bolted to deck joists and beams. The horizontal bench supports are pairs of 4-foot 2x 4's between which posts and legs are sand- wiched.
28mm thick deckboards can be laid on joists with 600mm spacing - though for higher level decks, this should be reduced to 500mm centres. Composite deck boards will require the joist spacings to be closer than this. Smaller joists - say 4x2 will need to be positioned at 450mm or 500mm between each decking joist.
Until now, the IRC didn't have deck joist span tables but the 2015 IRC includes a new one (Table R507.5) that will make it easy for deck builders to spec a joist size for a given span and joist spacing. The table includes spans for common lumber species used for deck framing like southern pine, Douglas fir,
The proper deck joist span (distance between supporting beams below the joists) for your deck should be known before you start building and is needed to draft your deck plan. The spans of joists varies based upon several factors: joist size, spacing between joists, decking material and wood species.
Decking. Decking boards span from joist to joist. If you use 5 4 decking, joists must be no farther apart than 16 inches. Decking made of 2x4s or 2x6s can span up to 24 inches. If you will run decking at an angle, you may need to put the joists closer together; know your local codes.
ground level, span Table 5 in AS 1684 can be used. Both these tables assume a minimum end bearing of 50 mm by bearer width, and intermediate bearing of 100 mm by bearer width for continuous bearers. To avoid splitting when receiving nails or screws from placement of decking boards, joists that are at least 45 mm
Joists are typically made from treated 2-by-8- , 2-by-10- or 2-by-12-inch lumber. The way to determine what is needed is to follow the formulas set down for maximum spans to make sure that the material you choose is appropriate for your project and capable of supporting the deck. The three factors are the species of wood,
Because I couldn't find a good load table (at least not quickly), I tried to calculate deflection and bending stress, and I can't see anything wrong with using 5 4" x 6" cedar boards (actual dimensions 1" x 5.5") across a 24-inch span: Decking load calculations. Perhaps I did something wrong in my calculations
bearing at one end of the joist to the centerline of bearing at the other end of the joist and does not include the length of the overhangs. Use Table 3 to determine Southern Pine joist spans based on lumber size and joist spacing. Refer to Table 4 for Southern Pine deck beam spans (LB) . Joists may bear on the beam and
Joists may cantilever up to ¼ of the actual adjacent span. For example, a 2 x 12 joist placed 16” OC. spanning 16'-6” between supports may cantilever up to an additional 4'-1 ½” for a total maximum length of 20' -7 ½”. Southern Pine Deck. Beam Maximum Spans . Lumber. Size. Total Deck Joist Span (including cantilever).