12x18 Spruce instead of Fir

[Rayn]

Woohoo!  We finally broke ground!  Well I'm putting up the 12x18 first - sort of a trial run and then the support building for a larger project.  

I found out that Doug FIr is special order where I'm building while spruce is readily available.  So do I have to change anything while doing the platform?  I would like to stick with 2x6's,  so if I do have to change I would 12" spacing over 16" do the trick?

[John Raabe]

I don't have charts for spruce lumber but do not think you would need to change framing sizes for that cabin. You might ask at the lumber yard if they have a span chart for the lumber you bought. Check the floor and roof spans to make sure you don't have to change anything. I was pretty conservative on my calcs since I never know the exact climate loads.