Stronger Post-to-Beam Connections

When a 6x6 post is notched to support a 2-ply beam, the post extension acts as a bridge between post and beam, preventing beam rotation and providing uplift-load-path continuity.

When a beam is supported by a 4x4 post (which can’t be notched), a 2-by splice block bolted and screwed to the post-and-beam assembly will prevent beam rotation. Note the metal connector, which is required when using this detail.

Diagonal bracing between posts and beams or between posts and joists is needed to counter lateral loads at the perimeter of the deck. Blocking may be needed when the faces of the posts, beams, or joists aren’t aligned.

Side-applied beams are inherently weak and prohibited by most building codes, unless the post is beefy enough—6x6 minimum—to be notched to support the beams.

On 4x4 posts, metal hardware—including Simpson Strong-Tie’s DJT14Z (shown) and USP’s SDJT14-TZ—can be used to support side-applied beams.

Using structural screws instead of nails will increase the uplift and lateral-load-bearing capacity of most metal connectors.

The USP BC400-TZ is a one-piece connector for attaching a double 2-by beam to a 4x4 post.

Connectors should be properly sized to match the framing. The Simpson Strong-Tie BCS2-3/6 is a one-piece connector for attaching a triple 2-by beam to a 6x6 post.

Hardware for post-to-beam connections is available for both new and retrofit construction. The USP PBS44, a two-piece connector for attaching a 4x4 post to a 4-by beam, can be used in either new or retrofit construction.

The Simpson Strong-Tie AC6Z, a two-piece connector for end-post installation where the sides of the post and the beam are flush, can be used in new or retrofit construction.

The USP PB66-6, a two-piece connector for beams that are narrower than the post width, is designed for new construction.

The Simpson Strong-Tie LPC4Z is a two-piece connector for beams that are narrower than post width (new construction).

The Simpson Strong-Tie LCE4 is two-piece corner connector for 4-by or 6-by lumber (new or retrofit construction).

The Simpson Strong-Tie EPC44 is a medium-duty 12-gauge end-post/beam connector for 4-by posts.

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