6x6 Pergola

Hey!

I'm completely green to the forum, this is me very first post!

I'm designing a modified pergola design for our deck, planning on using cedar 6x6 for uprights and horizontals for a uniform, modern look. My question is how long a span can I have with out having to worry about it sagging under it's own weight? Could I go 12ft? I googled span lengths extensively but only came up with 2x4, 2x6, 2x8, etc. Anyone know where I could find span lengths for 6x6 or 4x4 even?

I attached a picture of the "pergola", we're looking to use Shade Sails as the roof, so the structure is just a frame really.

[img:left]https://drive.google.com/file/d/0B9P_BsTtMfJMcDRBd0JrWUVXVGs/view?usp=sharing[/img]

If, as your model reflects, that the canopy is only some form of cloth and the 6x6 is only acting as a connector, this should be able to span 12' without sagging over time. I would suggest a timber free of heart if possible and "bark side up" (camber up) orientation.

I would also suggest reviewing some of the more "Asian" designs of structures as these do not use "oblique bracing" and have the more modern "rectilinear" format of modern design. A post, connecting beam, and 貫 (Nuki-bracing beam) configuration may be more to your liking and solve some other inherent issues within your design.

Regards,

j