Missing footing

[Alan CA]

Hi everyone,

I have a situation where a footing of a home storage room pillar is missing. The pillar is located at the end of a stud wall. The stud wall has footing which ends just before the pillar, leaving the latter with no footing.
What do you suggest to correct this? The concern is excavating adjacent to the existing wall footing.
Any thoughts?
Thank you in advance.

 

[Enable]

Would need a schematic to provide a more detailed answer. But in principle you have a couple options. Note: regardless of what you do you will need to transfer load from the pillar and span to a location outside of influence of excavation.

Option 1: Expose the earth and install micro-piles underneath the post location. Cap with a concrete pile cap. Cut post to rest nicely on new cap.

Option 2: Excavate to natural footing depth and install a footing. If undermining of adjacent footings is a concern, lag or underpin them as required in 1000mm increments.

Option 3: If the post is adjacent to a concrete foundation wall you could attempt to transfer the load into the foundation wall by installing a bracket above grade below the post. Depending on loads this should be doable. Cut the post to length to rest on the bracket.

 

[jayrod12]

Is this from that thread about large cracks in a basement slab?

If so, a plan view showing the existing footing location and size in relation to the post location and the proposed pad size would help.

 

[Alan CA]

Thank you for the replies, guys. This is a new situation that was not discussed before, at least not by me.
Here is a quick sketch illustrating the situation.

 

[Enable]

So it's a 3-ply 2X member resting on-grade? Based on the sketch I'll assume we are on nominal footings where we don't have to get below frost or anything like that.

All that being the case why don't you check the SOG for bearing and shear to see if a footing is even required? My hunch is the SOG would be totally adequate. Now is where I bet jayrod is going to laugh because he'll point to that basement thread and say "didn't you learn anything?!"

If you are still concerned after the checks I really don't see any difficulty in taking load off the member via some temp shoring and pouring a footing underneath. Am I missing something?

 

[Alan CA]

First, thank you fir the reply. The pillar is supporting another storey and a roof, which will require a footing as per the local codes. I can override it as this is an existing building but I'd need to make that judgment.
I thing an SOG will be a good idea. I'm currently considering it! Thanx for thr tip!

 

[jayrod12]

What size is the existing wall footing, what size does your post pad need to be? How close are the two to each other currently? What's the depth to the existing footing bearing elevation and the bearing pressure below that? What's the allowable bearing pressure you're using for design? What's the bearing pressure under your new pad going to be?

 

[Alan CA]

I don't have the exact details at the moment as it's weekend but I don't see them that related as it's a residential house so we're within specific range. I mean definitely 2x4 stud wall with footing that goes 4 ft. below grade, etc.

 

[LittleInch]

Why the concern about excavating?

The footing of the stud wall should be fine so long as you don't undermine it.

Does the post flooting need to be deeper?

If so just support the excavation with a short sheet pile or similar.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Alan CA]

Thank you very mich everyone for your replies. I think I have a start point to take this from, now, which is most likely limited excavation or SOG. Highly appreciated!