6x6 sill span

[adamblong]

This will be my very first build, a 12x20 4-bent structure #2 SYP. Bays 2 and 3 will be like a pavilion to park my lawn mower and such, bay 1 will be for firewood storage and will have a floor/platform. 

I live in Virginia, snow load is 20, frost line is 18". My question is this, if I place the ends of the 12' 6x6 on 2 concrete piers at either end with 4x6 joists 24" OC and standard decking as the floor... will that be too long of a span or will I need an additional pier in the center? 

For the roof, I was going to stick to standard 2x6, 16" OC into 6x6 top sill and with plywood roof deck and tin roof. 

Like I said, this is my first build so I am essentially clueless as if this is in any way on the right track. I really appreciate any input. Thanks so much.

~Adam

[Don P]

Hey Adam, welcome to the forum. Sorry no one has responded yet. I'm just catching up after reshingling my roof, the satellite guys put my dish back up today.

I strongly suspect you are overspanning everything but hard to be certain from a "word picture". Sketch it up, put in dimensions where appropriate, take a picture and post it and lets see what we can figure out.