6x6 Spans

[Andrew Purchase]

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.

312457

[Peter Kelly]

You might want to read through one of Tedd Benson's books on timber framing before building: http://bensonwood.com/news-blogs/media/tedds-books

Depending on your location, Douglas Fir or SYP 6x6 posts might be easier to come by than Cedar particularly in longer 14' - 16' lengths. Both woods are considerably stronger and less expensive as well.

[Lee Schierer]

The Saglator (http://www.woodbin.com/calcs/sagulator.htm) will let you design a "shelf" with any width and thickness you want. You will need to know the weight per foot for your beams.

[Ted Calver]

Hi Andrew and welcome to the creek. Glad you found us. That looks like a nice design. I would look up the properties of the particular cedar you intend to use i.e. western red cedar, and plug them into the uniform load formula here to get an idea of the amount of deflection to expect:
http://www.engineersedge.com/beam_calc_menu.shtml

[lowell holmes]

http://www.awc.org/calculators/span/calc/timbercalcstyle.asp

Check this site. There may be something you can use.

[Bradley Gray]

span calculators include live load, usually 30-40 lb/sq.ft. If all you are supporting is the beam itself (dead load) I would not be afraid of a 12' span.