Home Forums Hunting & Shooting Alaska Cabin/shop post foundation issue

middle post, front.... put whatever, carry the load with an engineered lam beam from post one, through the middle to post 3 or whatever the number....

I suspect the ties are more for decay-proofing the foundation than for structural... and a torsion box floor or similar will sit on the ties... direct contact or even damp crawlspaces would eat an engineered beam before they got it built.

Wel I think I'm going to try and remove that rock using some Ecobust to break up that rock. That seems like the best way to deal with this damned thing and make me feel good about that post being secure.

If it's in the middle it's only breaking a 16' span into two 8's right.?

It seems like you could pour some concrete over the top of the rock leaving a flat surface and just use a block to support the floor beam there since it's only a mid span. Leave enough room to use some wood shims that you can add to or knock out later if it heaves or settles. Just throwing out ideas....

The rock would be a better footer than anything you would do... and it is likely deep enough to not matter on heaving.

I am not in favor of making extra work for myself. Sounds like you are!

^^^^^^^^^^^THIS^^^^^^^^^^^^^^^^^^^^^^^^^^^ What is the span for your posts?

Yep. If the frost isn't very deep there, and it sounds like it isn't, that big old rock will probably be the best footer you've got. Then again, it would sure suck to have to jack and shim 8 posts because the big old rock is so stable and steady that it doesn't sink like the rest.

For a single story cabin that is not subject to cold regions design requirements, you may find that doweling into a good sized rock and casting a short concrete pier or pad to support an adjustable "Simpson EPB" bracket (if available in your AO) 6" to a foot above grade will adequately support your 4x floor girder. If you're using RR ties for floor framing, shim using a treated 4x4 (flat) in the EPB. If you keep the exposed threaded base short, they are good for around 3,000 pounds. For the stubby pier, you can use a precast pier block with a center hole set on a pad of concrete above the rock in various fashions.

Insert standard engineering design liability boilerplate here for the above limited suggestions based upon very limited information....

hmm... not familiar at all with torsion box. I've read it before in the code books but never seen it. Will have to read back up on it again

Just chopper-in a backhoe and dig the rock out.

I'll vote Sitka's idea, especially since you've already sunk 7 of 8.

But ain't it just the way for rocktop #8 to be middle front??

Torsion boxes make a TON of sense in remote locations because they use a lot less material to build a really stiff floor. Slick way to go but they need sound deadening insulation of some kind to prevent a drum effect...

`Much ado about not much..

If it were me, I'd dig down around the rockto good base (you mentioned it wasn't deep ) about 14-16 inches deep , or to a 3X3 foot square at least 6 inches deep (reinforce if you feel like it), whichever came first and pour a concrete slab to grade level or slightly above and either put in a - as mentioned before- custom built to tie adjustable device, or block to specs.

That rock seems golden to me.

And that's overbuilding I think. The best way to do things. It is after all a mid- support. The screw up or down devise would be more in favor with me than blocking. Simpler down the road. If ever needed.

Fixt