11'x13' ceiling span

Hi folks... I'm planning to build a ceiling for an 11'x13' span with 1"ply and 5/8" drywall layer. The min joist I should use should be 2x6 16"OC? Or 2x4 with sisters every second joist 16"OC? Thanks for the advice!

I tried the span calculator....and unless I read an encyclopedia and take the next two weeks looking up the vocab...I'll never figure it out!! Can someone help me out. "Standard" 2x4 vs "standard" 2x6 (the kind you get at Home Depot). I have no clue if they're pine, spruce, etc.... cheers !

I'm nearly as confused as you are on this whole joist issue, but I found this to be helpful: http://www.awc.org/calculators/span/rev ... secalc.asp This basically lets you input your span and load requirements, and shows you which lumber fits the bill. Still too many options for us newbies, but I thought it made a bit more sense than the other calculator. Hope this helps (at least a little...) Mark

Also, the lumber should have a stamp on it somewhere which indicates the species of wood and the grade. Next time your at Home Depot, take note of this info, and use it in the span calculator. I wish I could tell you what the run of the mill stuff is, but I still need to figure that out too. Look for something like the stamp shown on this page: http://www.oldhouseweb.com/stories/Detailed/10417.shtml

Wow! Thanks so much MM! That gave me an answer right away. I very much prefer that span calculator!!