Anyone have experience with a pole barn build on rock?

[dgoodwin10]

I'm in the early planning stages of a shop (30x 30ish) and am having to do this in phases. I've narrowed down the building type to a pole barn / post frame (looked at Miracle Truss but budget likely won't allow it) and am planning to build the roof structure now and use 2 20ft containers for dry space. When funds allow I'll pour a slab, frame in the walls and finish the shop out and sell the containers (doubtful, very). Typical pole barn post embedment is 4FT, however I have solid (likely competent) rock at or near the surface over a large portion of the proposed shop location. Research has turned up typical details like this:

This method will solve several problems, assuming competent rock can be located. I'm within the city limits so I'll need to submit plans for a permit but since this is 'covered equipment storage' they should be limited to a truss drawing, post attachment and site plan / sketch (I have not yet verified the requirements with the city yet). Local pole barn builders won't pull a permit so I'm proceeding assuming I'm the GC and will DIY this.

Anyone have experience with this? If your AHJ required it, were you able to get drawings from a vendor or had to go to an architect?

For reference, the shop will be built here. The flat area to the right of the trailer is exposed rock and it pops up in several other locations on this corner of the lot:

 

[Loganwayne]

to have competent rock and be allowed to pin to it you will most likely need an engineer to verify which may require several borings. AKA alot of extra money.

if i was trying to do what you wanted i would probably put down a compacted gravel base 6-8 deep, space your containers 30ft apart and set trusses across it all. they would be big but manageable with a couple guys helping and/ or a small crane. you would need a connection detail for container to truss.

then you could pour your slab in between and finish in walls as money and time allows.

 

[orange150]

You also will have the potential of differential settlement if some columns/footings are on rock and some are bearing on soil. Maybe not as important on a structure like a pole barn, but still something to look out for.

 

[awheelterd]

I used Simpson wet set brackets with footers for my pole barn. We have a high water table and plentiful termites so burying wood in the ground was a nonstarter for me. Barns been up 2yrs and hasnt fallen down yet

 

[dgoodwin10]

to have competent rock and be allowed to pin to it you will most likely need an engineer to verify which may require several borings. AKA alot of extra money.

if i was trying to do what you wanted i would probably put down a compacted gravel base 6-8 deep, space your containers 30ft apart and set trusses across it all. they would be big but manageable with a couple guys helping and/ or a small crane. you would need a connection detail for container to truss.

then you could pour your slab in between and finish in walls as money and time allows.

I hadn't considered using the 'permanent' trusses with the containers acting as the walls - I like this idea.

I don't want to get the city involved if I don't have to, but I also don't want an inspector driving by (which has been a big push lately) and putting a stop to this project. Hoover doesn't seem to care about temporary structures like prefab'd sheds, etc. but anything that has a poured foundation they seem to take interest in. I'd be curious how the city viewed this and what they'd require, if anything.

 

[paradisePWoffrd]

I know it is not your planned direction, and I have no experience, but what about pouring the concert first? Does that help with the situation? Can you put down a gravel base and pour concrete with wet set anchors in them, and then put the posts/building up later as you can afford?