Just a quick question. What is “best practice” for anchoring diagonal bracing for a 4′ high outdoor freestanding deck? I have sonotube 12″ piers for 6″x6″ posts, postcap hardware, and about 44″ of post above ground level. Would 4″x4″‘s cut on the 45 and nailed or screwed in place do it or should I mortise out the post as in timberframing? I just want to do it right…
Thanks,
Dave
Replies
Are you sure you need diagonal bracing?
Is the deck attached to the house?
Are the posts sunk in concrete, or are they on metal post bases?
Regardless of those answers, 4x4's and mortising is overkill. 2x6's lag-screwed to the posts should be more than sufficient.
Regards,
Tim Ruttan
No, the deck is not attached to the house, there are sonotubes in the ground, post cap hardware attaching the post to the concrete pier and the post is bolted to the beam. There is a slight bit of sway with all the joists in. That's why I know I need the bracing...
Diagonally brace the deck surface, and most of the sway will disappear.
"To do it right" means many things. At 44" you may not need these sway braces but they never hurt, check local codes. If just for extra security, lags work. If for aesthetics then that's up to you. Mortise them in, use 6x6 to match the posts if you wish, I've half-lapped sways with half-dovetails and they look great. Is this job on your place? If not what does the client want to see/pay for?
The deck is on my place, I really like the dovetail idea!! Might just slick it up with that.Thanks all for all comments fellas.Dave
First off, diagonally brace the platform itself, either with diagonal decking, or with a 1x or 2x fastened diagonally across the bottom of the deck.
If the posts are set into the ground, you probably don't need any diagonal bracing on the (4-foot high) 6x6 posts. If not then knee braces both directions on all four corners would be appropriate. For a large deck knee braces on about every other intermediate post would probably be wise. 2x4s are fine for the knee braces. Use 16d or 20d nails or lags, not deck screws. You can mortise them into the posts if you want, for appearance, but not generally necessary structurally.
In Calif. we have to use 4x4s, lagged into post and beam.