I'm building a 12 foot Octagon Gazebo on top of a existing deck. I'm using 4x4 by 8 long PT timbers, attached to floor with molded plastic supports. Roof is up and Hand rail all around on 6 sides with 2 sides too remain open. Unfortanely the Top structure is very wobbly. Any suggestions for better bracing?

Thanks

Can you attach picture of the structure showing how the upper scetion was constructed?

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Sorry Rick but I am going to have to let someone else step in here. I am in a very remote location with a marginal computer and just can't open many files.

The problem with your design, while it looks nice, is that all the pieces are either vertical or horizontal. Think of 4 pieces of wood nailed together in a square like a window frame. This shape is unstable: if you push the top sideways, it is very easy to push it out of square.

You can add structural ridigity in two ways:

1) use stronger metal brackets to attach the posts to the deck, or to attach the roof frame to the posts. Its probably too late to change the ties since your gazebo is already up.

2) add wood bracing in the form of 'triangles' to get away from your square design. You can make braces in your gazebo that are also decorative in a number of locations:

a) between 4x4 post and the roof, on each side of the post.
b) from one post across under the roof to the post on the opposite side
c) You could replace the replace the fencing you've put up with pieces running in a big 'X', but that would not give you the 4" spacing you need for code on a raised deck railing.

Thanks,

That makes a lot odf sense. Well do some modifications

Rick