Wood Purlins Spacing?

[RainT]

Hello, this is my first time to design a wood,
can you help me.
The bldg is one story 8.6mX8.6m I am going to use wood truss. The question are, what is the maximum spacing of the truss I should use and what spacing of the purlins I use? the bldg will carry 30psf.

 

[boo1]

Typical wood trusses are set at 24" O.C. What is your roof ing material and wind loads?

 

[whyun]

Typical roof joist spacing, as boo1 suggests, is 24" o.c. Other typical spacing is 16". Standard sheet of plywood is 4'-0" x 8'-0".

To determine a reasonable spacing for the wood trusses, first select the typical joist you would like to use (say 2x4 or 2x6), determine a maximum span for the load condition, then use a even number feet that is less than the maximum span.