Expert: Bruce E. Johnson - 10/12/2008

Question
Hi -- I'm building a shed-type roof over an existing deck in the Detroit, Mich area.  The roof will measure 17' x 14'.  It will be essentially flat (2" pitch), will have a snow load value of 40 lbs/sq ft, and one end will be tied to the house framing using a ledger board.  The beams on the perimeter will be supported by 4" x 4" posts buried 42" in cement.  I want to cover the 17 foot rafter/beam spans without any support except at the ends of the span.  How can I accomplish this using lumber that can be bought at the local Lowes/HomeDepot, i.e., S-P-F, size 2 x ___?
Thank you for your time.
James  

Answer
Hi James, check out this website: http://www.southernpine.com/spantables.shtml it gives a detailed description of weight capabilities and spans for joists.etc.
The same southern pine council has information for beams and headers under this link.

http://newstore.southernpine.com/cgi-bin/newsopine/product?;5;


I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com