There’s been a horizontal crack in my house’s foundation going all the way around the house since we purchased the house 12 years ago. The foundation walls look like ordinary cinder-block, with a ¼” layer of ‘cement-facade’. The other day I noticed some of the cement was loose, and pulled a few chunks out. Underneath the cement facade and between the cinder-blocks was a very rusted steel bar. It looks like the rust’s expansion is what’s causing the crack - pushing out the cement facade all around the foundation.

Here's a couple facts about the house:

  • The house was built back in 1942, we believe it was a kit-home, and was renovated in 1970’s. To my knowledge, there’s no renovations done on the foundation.
  • The house is built on a small hill - the basement floor is a little bit above-grade for the nearby road, but the crack itself is a few feet from the local ground-level.
  • As far as I know there’s never been any water seepage problems in the basement.
  • The house is near Minneapolis, Minnesota - the basement is heated, but it certainly does get some temperature-swings in winter.
  • This crack was repaired before - looks like mortar of some sort was slapped into the gap after the cement-facade crumbled away the first time
  • The house was professionally inspected prior to us buying the place, and the inspector did make an incidental mention of the crack, but didn’t say we should be alarmed or anything.


  1. What the heck is this metal thing? Some sort of rebar?
  2. Does this need to be fixed?
  3. Any way I can fix it myself?
  4. If not, what sort of professional do I need to call to have it evaluated/fixed?

Photos: Wide shot

Close-up after I removed some rust

  • I live in a skyscraper and a crack was found in a pretty bad place. The construction company waited until the crack had fully expanded and then filled it with an industrial grade epoxy.
    – ADH
    Jan 9, 2017 at 21:28

2 Answers 2


In 1942, there was a war on, construction standards where not well developed, and concrete masonry systems were not nearly as prevalent as they are today. Which is a round about way of saying, that it looks like old construction that does not utilize contemporary practices.

To me, it looks like horizontal reinforcing. Today, it would probably be done with a prefabricated wire 'ladder' or similar module. In the old days, those weren't common so it is probably a small reinforcing bar (perhaps 1/4", but that's just a guess based on the time frame).

For peace of mind, it might make sense to hire a Professional Engineer to take a look; evaluate the situation and provide advice. Then there is will be more information for making an informed decision regarding what, if anything, needs doing; when it needs to be done; and how feasible it is to tackle on your own versus hiring construction staff.

  • I think you are right. I thought cinder blocks at first with some rebar in between a joint... but looking closely it doesn't look like it. No idea what they did here.
    – DMoore
    Jan 11, 2017 at 20:01
  • @DMoore I once knew an architect named Jan Able who was restoring Cad-a-zan, John and Mable Ringling's (of the Ringling Brothers Circus) house in Sarasota. Some of the walls, she said, were poured concrete reinforced with railroad rails. One of the issues with FL Wright's textile block buildings is the 1/4" reinforcing exposed to moisture. In the old days, most places, building codes and practices were very different from today. Particularly for single family homes.
    – user23752
    Jan 13, 2017 at 19:18

This is used in masonry construction of cmu foundation. Its known as ladder wire. Typically every other course.

From what it looks like, it has rusted and popped the mortar joint.

Very concerning due to the fact it only happens with moisture. Therefore a slow water void/leak has created an avenue for water penetration.

  • This is only one quarter of the answer Aug 2, 2023 at 6:22
  • Thanks for the answer - yes, moisture is/was getting in. There's a window just above this spot with an old wooden frame. That frame is probably leaking a bit during big storms and there's some seepage. We're getting those windows replaced with block at some point.
    – john3103
    Aug 17, 2023 at 22:10

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