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swaying of a 10' deck
2

swaying of a 10' deck

swaying of a 10' deck

(OP)
How can we minimize the swaying of high decks without
adding x-bracing. The x-bracing is in the way. The decks
consist of wood members. The posts are 4x6.

RE: swaying of a 10' deck

2
Two ways for open decks:

1.  Add 2X flat diagonal bracing under the deck joists, nailed to the underside of the joists, or

2.  Add 2X diagonal flush blocking with metal strapping over, nailed to blocking and joists.

Either way has worked well for me in the past.  No worries.

Another way is for the deck is to be covered with plywood, then the plywood serves as a cantilever floor diaphragm.  But this is obviously not feasible unless the deck is waterproof.

Mike McCann
McCann Engineering

RE: swaying of a 10' deck

Put your deck boards on a 45 degree diagonal.

RE: swaying of a 10' deck

If the deck is over about 6 or 8' high and you refuse to use diagonal bracing or brace off the house, the 4x6s will always give you some sway.

Is it built to code? - There is a difference between minimum acceptable strenght and good construction.

RE: swaying of a 10' deck

Use steel beams cantilevered out from the house to carry the deck thus eliminating posts altogether.

RE: swaying of a 10' deck

Knee braces may also help reduce the sway.

RE: swaying of a 10' deck

you could also beef up the connections at the beams and posts to be more rigid. also make the perimeter beams bigger and lag bolted to the posts. i've built a 15'x25' deck about 12 feet off the ground independent of the house and the thing is solid as a rock. relied on doubled up 2x10's around the perimeter and another in the middle. lag bolted all the connections to 4x6 posts. ran decking at 45 degrees. made sure to have blocking at appropriate locations to stiffen the thing along the joist spans. we used a few small diagonal braces but near the tops of the posts and they're completely out of the way so that you can go under the deck.

RE: swaying of a 10' deck

(OP)
Thanks guys. All responses were helpfull.

RE: swaying of a 10' deck

jike's suggestion for knee braces is a good one, just make sure the post and beam you connect to can resist the moment from the eccentric connection.

You say the x-brace is in the way, can you do a chevron brace (inverted V)?

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