Deck beam-to-post connection — notched 6×6 for a 2-ply beam, post cap required for a 3-ply
A 2-ply beam can sit in a notched 6×6 with two ½" through-bolts (or a post cap); a 3-ply beam must use a post cap — notching is not allowed for 3-ply (IRC R507.5.2 / DCA 6). A positive connection is always required; side-bolting an un-notched post is prohibited.
What this diagram shows
A side-by-side of the two code-approved ways to connect a deck beam to a post. On the left, a 2-ply beam sits in a notched 6×6 post held with two half-inch through-bolts (a post cap also works). On the right, a 3-ply beam sits in a metal post cap on top of the post, because notching is not permitted for a 3-ply beam. A note states a positive connection is always required — bearing alone is not enough — and bolting a beam to the face of an un-notched post is prohibited.
Use this diagram — free
You're welcome to use this diagram on your own site, blog, handout, or lesson at no cost. The only condition is a visible credit link back to the source page. Copy the snippet below and paste it into your page — the credit is already included.
Please keep the credit link intact and don't alter the diagram itself. Redistribution as part of a competing diagram library or template pack isn't permitted. Questions? Reach us via the site.
Was this diagram helpful?
Deck Beam Span Calculator
How far can a deck beam span? Free calculator for beam size, ply, post spacing, footing & cantilever from the joist span it carries — per IRC R507.5 / DCA 6.
