Placement and number of piers for a foundation

[tvclarkak]

I'm building a 24' x 28' cabin that will have an 8' deck.  I'm using sono tubes (with bigfoot bases) for a pier and beam style foundation.  My thought is to frame the joists for a 24' x 36' platform (to include the 8' deck).  Running 3 concrete piers across I can easily support a 24' girder beam (spacing the piers at 12') and I can run 4 piers the long way (36') for a total of 12 piers.  I've checked the max spans for both my girder beams and joists and all looks good.

My question is regarding the placement of the piers.  Since the floor framing will be shared by both the cabin and deck, the front wall of the cabin will not fall directly above a row of piers, rather about 4 feet from it.  This isn't a cantilever issue since the joist will be supported at the end about 8 feet away.  I assume since it's an outside wall it's considered load bearing.  Do I need to add a row of piers to fall directly under this wall?

[Don_P]

Yes, you should have a row of piers under the load bearing wall.

Those joist should probably be treated as well.