Layout for pier block/beam foundation

[That One Guy]

Drawing up plans for my utilities shed to house diesel generator, batteries, inverter and a small oil fired heater.  It's going to be 12' by 12' with a shed roof, 2x6 walls and pier block and beam foundation.  I'm not wanting to do any excavating other than where the pier block will set.  I plan on digging a 24"x24" square hole down to the gravel base (24"approx.) and filling in with gravel to grade.  Pier block will set on gravel pad.  I'm thinking that four pier block will suffice with beam running front to back and stepped in 18" from the rim joist.  Not sure of the beam dimensions for this size building.  Concerns I have include: Do I need more pier block, more beams, more or less cantilevered distance from beams to rim joist? Does anybody have input concerning the direction I'm headed with this?

[manhattan42]

For a structure this small, why even place it on piers and beams?

Why not just place it on a floating concrete  slab or resting on 6x6 treated timbers laid directly on grade?

[PEG688]

   TOG  Gee your screen name is a acronym

 Is deep frost a issue where your building ? If so I'd go below the frost line with your footing holes.

 I'd also recommend you use concrete for your beam base supports , either a sonotube , rent a pwr.auger, drill the hole get the 8" auger , use 6" sonotube  , slide tube in , adjust for desired heigth , pour full of mud , set ZMAX post base .  For this small a building the "big foot " base souldn't be required.

Or hand dig your hole , form up the top , fill w/ mud , set ZMAX post base .

I'd also do 3 post bases per beam , with a gen. running in the building vibration thru the floor would be another concern with the gravel / stone rubble pier pads.

 Good luck , PEG  

[John Raabe]

The Little House plans have a 12x18 building with a pier and beam foundation. Easily pulled in 6'.