Sonotube footings

[rotorgoat]

I can't get any large equipment into my building site and would like to use Sonotubes as I'll have to hand dig each hole. Does anybody have a formula for the size and spacing required. I'll be supporting a 35' X 28' with a loft. Lodgepole logs averaging 12" dia. Any leads would be much appreciated.

[Shark]

The spacing depends on the spans you can go with whatever you are building with.

If you have access to span tables that would be a start.

I used 24" diameter tubes, around 7' between each or so...probably overkill but hey. Pics in my sig if you're curious.

[rotorgoat]

I checked out your pic's--looks like you have both a footer and the tubes. I couldn't quite tell if the footer is separate from the tubes or if the tubes were placed on the footer. Are you going to put a block wall on the footer? Did you have plans drawn up or do them yourself? Was any engineering data required for your building permit? How deep did you go with the footer and tubes? What part of the country are you building in? Up here in Wyoming they want footings 48" deep for frost. I feel like I'm asking more questions than a 5 year old at bedtime! Thanks for the input. Keith