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My fiancee and I recently moved into a 1922 brick craftsman-style home. The front porch has a ~4" poured concrete floor and large solid concrete railing caps (12"W x 4"D). Brick columns support the roof, and brick posts & balusters support the large railing caps. I mention all this to emphasize this is a lot of heavy material.

When we inspected the home we noticed that this porch's floor and railing caps had some settlement cracks. It also appeared much of the lower brickwork on the porch had been re-pointed. Upon further examination, it was clear that the north side of the porch had sagged about an inch. Someone had clearly placed extra wood spacers between the roof and the corner column to compensate. When I went beneath the porch (it's fully accessible with standing room via the basement), I noticed a few things:

  1. Several temporary support columns and one 8x8" CMU column were added underneath the sagging side of the porch.
  2. The footings beneath the brick go down about 18-24" below grade and this little room's dirt floor is about 18" lower still.
  3. Someone (not me!) shoveled material out from around and beneath the footings (hence how I could see where they bottom out).
  4. Tangential, but of note, the original wooden concrete forms for the porch floor were left intact above head. I guess plywood hadn't yet been invented in 1922 (or was rare/expensive) so it initially looked like maybe the whole floor was being supported by 2x4s and 1x4 slats! This wood is not in the best of shape and I've thought about removing it -- if for no other reason than to have a better attachment point for support columns.

So, it seems that someone may have decided it was a good idea to undermine the footings in this old coal chute/storage room, then--half way through--realized it was causing the porch to sink. They put up some columns and patched up the cracks and walked away. No idea how long ago this may have been. Judging by the condition of the repairs, I'd guess about 4 years ago. It doesn't appear there's been too much (if any) movement since, but it's damn concerning nonetheless.

The question is what to do about the situation. I've batted ideas around with several people but can't come to a definitive consensus.

One camp suggests building a knee wall up from the floor so that it overlaps with the existing footings and connecting them with rebar to arrest further settling both down and laterally.

Another camp suggests jacking up the corner (I do have a 20-ton screw jack) and incrementally under-girding the footings from below. Then building the knee wall as described above--mostly to avoid potential lateral shifting.

In either case, I plan to add several more concrete columns for "belts and suspenders".

I've been at a stand-still of apprehension. Being new to the town, I don't have a network of trusted contractors. I've had a couple people look at it and, I just didn't get the sense they had a good handle on this situation or enough experience with older buildings. I'd greatly appreciate any insights from those with experience and knowledge to help me move toward fixing this correctly (insofar as that is possible).

Thanks.

PS: The soil here is mostly red clay. Your typical eastern Tennessee type of earth.

PPS: Uploaded a gallery of photos for reference: https://i.stack.imgur.com/RhfEO.jpg

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2 Answers 2

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It looks like somebody tried to lower the basement floor, going about it in a most dangerous way. With that much dirt removed from beside the foundation is a seriously wrong move, I am glad to see it is still up with not much settling. The cracks you show are minor compared to what I have seen in homes that have simply settled or shifted for one reason or another. You need to have a company come in that specializes in underpinning

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  • Thanks for the helpful input. I am also grateful it hasn't collapsed! Just to clarify, the entire basement doesn't look like this. The main structure is supported by a poured foundation and this is just a small offshoot chamber with a hobbit-door leading to it. I think they hogged out a compacted earth perimeter rather than lowering the whole area. In the spirit of DIY, I wonder if I could drill several 1" rebars into the corner (maybe weld them to a beam) and catch that ledge with the screw jack? The hydraulic helical anchor system looks awesome, but, maybe overkill for this situation?
    – evantish
    Sep 25, 2015 at 17:17
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    You cannot do anything with what you have there. There is no soil beside the footings. What ever you do to the footings will not improve the soils bearing of what is not there. Adding rebar, or the act of adding rebar will introduce vibration which is never good in poorly supported concrete. The underpinning style I am used to using with this situation is digging out a 2' rectangular pier under the footing in question, setting rebar a certain way pouring it letting it set and do that in a certain sequence under the whole area in question.
    – Jack
    Sep 25, 2015 at 17:46
  • The hydraulic helical anchor is a very expensive system which I have seen used as well, total overkill. It can be used to lift your porch, but since it is a masonry porch, I totally advise against it, even if it could be afforded.
    – Jack
    Sep 25, 2015 at 17:48
  • Ok, so I'm clear, you're suggesting to stabilize it in place and not lift. I assume the concern there is cracking bricks and mortar joints.
    – evantish
    Sep 25, 2015 at 17:58
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    The drawing was very helpful in understanding what you meant, the same rule applies, the vibration will be bad. The rebar or other metal for that matter will not "set well" as far as I know. It may be a good idea, that I can't say. That would take an engineer to say. I can only prescribe what has worked for me in the past and confirm what you have is bad. In answr to your question about lifting, PLEASE do not lift. The bricks cannot handle that type of rapid movement, The problem happened gradually over time and lifting it up will only make it worse.
    – Jack
    Sep 25, 2015 at 23:25
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My instinct is dig and form a secondary footer offset from original footer, add rebar and block and pour a slab that fills the space between. This will allow the concrete to carry any lateral load in compression to the rebar and new footer. This should stabilize the original dugout footer and then you can use the new footers to add pilers to brace the porch. This comes from no knowledge at all about foundation repair. There is probably a much better solution but I like concrete.

Side not, nice thing about a coal chute is you can pump concrete through it.

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