I have an older house (circa 1919) that was built without a basement (just a crawl space). About 1965 a basement was added.

Along one of the old concrete foundation walls there is a 7 foot section that has nothing under the bottom of the wall! (See image below.) In the last 10 years 2 pieces of the wall have cracked off the bottom . The pieces weigh maybe 150 lbs and 50 lbs. This concrete wall is only about 2 feet in height (the bottom is maybe 20 inches below ground level).

It seems to me that this wall is at risk of falling in completely. I realize I could call in a professional to fix it ($$$). But would like to at least consider any options I may have to fix this myself. I am an avid do-it-yourselfer and in 25 years have only ever hired a contracter one time (to replace my steep roof).

Anyone have any good ideas about how to fix this problem? Extra points if your suggestion is work I could do myself. :-)

Thanks! enter image description here

EDIT: My diagram may give the wrong impression about one point: the old foundation wall is unsupported for a 7 foot section only. But somehow it is still hanging in place. The rest of the wall does have dirt under it holding up.

  • Where is the house? A 20" high foundation wall (and no footer) isn't much better than no foundation. What is this section supporting? Is the new wall supporting the house? Was any of the work permitted (original construction or new wall)? Even in 1919, there were building codes. If it was my house, I'd bring in an engineer or foundation specialist to assess the situation.
    – fixer1234
    Jan 22, 2018 at 2:51
  • As fixer said: Was any of the work permitted (original construction or new wall)? You might have recourse against the previous owner to get that fixed and that may depend on when you purchased this home as well. This is a substantial hazard and most likely subject to disclosure however every state is different and for this it would depend on the state your home is in..
    – Ken
    Jan 22, 2018 at 11:05
  • @fixer1234 To answer your questions: The house is in Pennsylvania, United States. This section is supporting a weight bearing outside wall of the house. The new wall is likely supporting at least part of the weight. There are shims between the new wall and the floor joists that are tight/immovable. The work should have been permitted in 1965 for sure. The new wall looks well done. Jan 22, 2018 at 22:42
  • @Ken - I have owned the house for almost 25 years, so I am not sure if I would have any recourse for something so long ago. The home was inspected and passed for an FHA loan, which has stricter than normal requirements. Jan 22, 2018 at 22:44
  • @JoeGayetty after 25 years you may not have any recourse but just in case check with an attorney ask for free consult it will not hurt the worst they can say is no. Inspectors have certain disclaimers like an 'entertainment purposes only' clause and usually are recommended by the realtors who provide them the bulk of their business (conflict of interest). My home (FHA after 2009 mortgage requirements) passed inspection, I will spare you the long list of (code & safety) items that should have caused the inspection to fail.They did take pictures and give model of appliances - woo hoo :-(
    – Ken
    Jan 23, 2018 at 18:59

3 Answers 3


This is probably just a good comment but I would highly suspect that the old wall is providing zero support. Just because things are connected to it does not mean that it is supporting those things.

Given that a new basement was poured there is a 99% chance that they pushed those walls up to provide load support to the entire house. Since this was done in 1965 I am pretty sure I am correct or you would have a warped/bent floor on the edges.

The concrete that is malfunctioning on you is simply concrete breaking down because it is holding up itself. Concrete is really bad at this. That is why structures like parking garages require tons of rebar and meshing even though they are mainly concrete. And even then concrete will crack and fall. I am guessing yours has nothing internal supporting it.

My recommendation would be to fill in the void as well as possible with drainage rock and aggregate. There are techniques you can use when adding the rock to pressurize the load for that small wall better. But note that the load is only itself.

The other note I would make is the most concerning part of your picture is the angle of the missing dirt. It seems that the void clearance runs into your usable foundation. I would add enough dirt to add a size ramp to offset any wicking water to the other direction (8-12 inches higher).

  • I ended up digging from outside (a hole about 3 feet wide along the old foundation) until I reached about 24 inches below the bottom of the unsupported wall...so I could see inside the basement. Then I built a form inside the hole and poured in about 1800lbs of concrete, essentially creating a pier about 3ft x 3ft under the unsupported wall. I put a piece of vinyl tarp between the old foundation wall and the new concrete to keep the new concrete from adhering to and pulling down the old foundation when it cured. It turned out pretty good I think. Jan 7, 2020 at 21:09
  • I hope it turns out well but you could have potentially caused more long term issues. It is probably low risk but the weight of the newly added concrete could very well push on the basement wall and eventually cause it to crack or swell. I doubt that is the case but is a risk of your fix. I really don't think the old footing was doing anything at all. The other side of this is the new concrete could reinforce the existing wall. You just simply don't know without know the offsets and angles of support.
    – DMoore
    Jan 7, 2020 at 21:12

Because the old wall is at the perimeter of your house, it is/was a bearing wall. You’ll need to determine if it is still a bearing wall. There are a few things you’ll need to verify: 1) Is it still supporting a bearing wall? 2) Is the house “resting” on the old foundation? 3) Is the old foundation still tied to the original wall above? 4) Is the old foundation “tied” to the new wall? 5) Is anything (plumbing, electrical, etc.) anchored to the old wall?

1) It’s odd that it does not have a “footing”, but often the builders of those old houses didn’t include a footing. If the floor joist run perpendicular to the wall, they could rest on the new wall and then cantilever 24” to support the wall, floors (if any) and roof above. If the floor joists run parallel to the wall, it may not be needed.

2) You’ll need to determine if the house still rests (touches) the old foundation. You can do this with a piece of paper and try to slip it between the foundation and the wall above.

3) The house may not be resting on the original foundation, but it may be tied together with foundation bolts, straps, etc. if so, the wall above could be trying to support the foundation. If so, you’ll need to “cut it loose”.

4) Likewise, the new wall could be tied to old wall. If so, you’ll need to verify this and, determine the reason.

5) I’d disconnect all plumbing, wires, etc. in any event.

If you remove the old foundation, make sure you install plywood, (or something) on the bottom of the floor joists to keep rodents out...and if there are old crawl space vents, you’ll need to figure out what to do there too.

  • The old wall still appears to be providing support, but I will have to investigate more when I am able. The joists run perpendicular to the wall. And to add to the mess, my electrical panel (fuse box) is on the old wall about 6 feet from where this unsupported section of wall is located. Jan 22, 2018 at 22:51
  • It would surprise me if a 1919 home had straps to the foundation. After the 1906 earthquake in sanfrancisco it took until the 20' s before foundation bolts were more common based on the work I have done in the past. Guess you are lucky it is at least cantilevered, but it should be re supported pain in the but if the wall is saging already , will need to Jack it dig out a proper footing and pour new concrete under the existing wall if it can be saved.
    – Ed Beal
    Jan 22, 2018 at 23:21
  • Let us know if it still supports something and where the electrical service come from...above or below.
    – Lee Sam
    Jan 22, 2018 at 23:30
  • " The joists run perpendicular to the wall". Then what you now have is a cantilevered structure with the support being provided by the new wall, and the outside wall of the house, and the 2nd floor i there is one, being supported by the cantilevered floor joists. Unless things were engineered this way, it's probably not something you want to leave uncorrected.
    – SteveSh
    Jan 8, 2020 at 13:18

That's a potentially very dangerous situation. Here in Toronto, due to the skyrocketing housing costs people have turned to underpinning to add basement height in order to create a livable space. My role is to restore the HVAC, water heater and often install hydronic radiant floor heating. The pins are usually no more then 24" wide and done in three stages to avoid damage to the rest of the house. The underpinner I contract for does several jobs a month and has one of the best track records in the city. I have heard about house collapses when DIYers try to underpin. It's something not to be trifled with. At the very least, have an engineer/architect look at it and guide your course of action. Soil conditions dictate what can be done and what can't be done. I wouldn't suspect that you are in danger of a catastrophic collapse but you are probably in danger of having to do serious repairs to your home because of sagging, shifting and cracking.

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