Guard Posts for Angled Deck Corners
Prescriptive codes don't address the connection at less common angles, so base the connection off more typical ones using bolts, structural screws, blocking, and steel tension ties.
I’m building a deck with a 45° angle at one corner. I’ve looked through all the guard-post connection details in Fine Homebuilding articles and videos and I don’t see any that show how to mount a guard post on a 45° corner. Do you have a solution for attaching posts on the outside of the rim joists at angled corners?
— Josh
Editorial Advisor Mike Guertin Replies:
Unfortunately, there aren’t any prescriptive details for 45° or other angled deck corners in our normal go-to prescriptive guide for deck connections, the American Wood Council’s DCA 6. I haven’t found published instructions from fastener and connector manufacturers either. When I frame decks with off-angle corners, I make connections based on more-typical guard-post connections.
I use bolts, structural screws, blocking, and steel tension ties to create a continuous load path that connects the posts, rim joists, and deck joists. I’ve used both single- and double-post connections. The double-post arrangement is more rigid, but looks bulkier. A one-post 45° corner has its single post centered on the rim-joist miter.
Beveling the rim joists at the corner creates a flat surface for mounting the post, and an angled block on the back reinforces the joint. Structural screws connect a block perpendicular to the rim joists to the nearby joist with a sistered block on its side. A tension tie screwed to the block transfers the load on the post to the deck frame.
A two-post 45°corner has posts on both sides of the miter. One is attached using prescriptive details found in DCA 6 and following the tension-tie manufacturer’s instructions. The post is connected with a threaded rod to a tension-tie bracket securely fastened to the side of a joist. An extra joist can be installed or blocks can be added to a common joist for lining up the tension tie with the center of the post.
The second post is attached to perpendicular blocking between the rim and an adjacent joist. The space between the rim joist and the first adjacent joist is often too short for the tension tie’s length, so a second in-line block provides room for the tension tie and strengthens the connection by spreading the load across two joists. When cutting and fitting the blocking, be sure to cut the blocks so their miters are tight and there’s a snug fit between joists for the strongest connection.
RELATED STORIES
- Options for Fastening Deck Guardrails
- Rock-Solid Guard-Post Connections
- Code-Compliant Guardrail Post Connections
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