How are deck beams or girders attached to posts?


Beginning with the 2015 International Residential Code, wood beams or girders supporting deck floor joists or gravity loads from other sources must have full bearing at supporting posts. At ends of wood beams or girders, a minimum of 1.5” of direct bearing on wood or 3.0” on concrete or masonry is required. Beams and girders are no longer permitted to “straddle” posts and be supported with through-bolts for the transfer of gravity loads to vertical supports, as illustrated below. Additionally, beams and girders must be attached to prevent lateral movement at supports which is commonly achieved either through notching of posts or using manufactured connectors. The illustrations below are from AWC’s Design for Code Acceptance No. 6 (AWC DCA-6) which can be downloaded at https://www.awc.org/codes-standards/publications/dca6. Similar illustrations are found in IRC Figures R507.5.1(1) and (2).