HELP: vertical foundation crack in new construction

Zhixin Tang · 2003-10-04T14:47:40+00:00

Hi, I found out there is a vertical crack on the foundation wall(poured concrete) all the way from ceiling to floor. It is on the 40'foundation wall, in the middle of garage, close to steel pieces in theconcrete, about 1/8" wide. The foundation is only 2 months old and thehouse is close to completion.I think one wall is settling down more to cause the crack. I am afraidthat the crack will become bigger when settling continues. Is not rarefor a 2-month foundation has such a long and wide crack? I amcurrently requesting the builder to hire a structural engineer toassess the problem.Since the house has been closed, I may have to option to walk away ifit is a serious foundation problem.Folks, I would appreciate your advice on this problem. Also if I doaccept the home, I have to disclose the problem when I sell the housein the future?Thanks.Tom

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Dan G 22 years ago

I believe you said you have a block foundation as opposed to a cast in place concrete wall. Jargon in the trade would call yours a block or CMU (Concrete/cementitious Masonry Units) as opposed to CIP concrete wall.

I am not in a position to tell you what will work, especially as I have not seen it. I can offer some ideas to consider. I gather that the top of the wall is still accessible. Did the footing break and go down leaving a wider crack at the top than at the bottom? or did the wall get pushed in causing a bigger crack at the top? If it was pushed in, has it been pushed back out? If the footing has been broken, I would suggest tearing the corner down, reinforce the footing, and relay the corner. If the wall moved slightly from backfilling pressure, I would excavate the corner to push the wall back into line. I must say it sounds unusual to me for the wall to fail close to the corner, rather than out at mid wall. I would take a hammer drill with a very small bit (1/4") and test vertical cells to verify which ones are filled. You will need to test at least high, medium, low in every vertical line of cells near the failure. If there are any with voids in the filling of the cells, I would make sure to have them at least grout injected, preferably vibrated full of 3/8ths chip mix real concrete. I think the dowels that are being proposed should maybe be longer to get from the good corner well past the break into a portion of the side wall that did not move or fail. I would expect the pins to be epoxied. I agree that a poured floor holding the tops of the walls will strengthen the situation substantially.

The damp proofing will need to be reapplied. I would ask for some form of guaranty based on continued failure, crack increasing, etc for a set term, perhaps 2 years, with a healthy clause about excavation and remedy. It sounds as if your builder wants to work with you. I think both of you should split the cost of having a structural engineer assess and recommend the repair method for each other's protection and continued ability to work together.

#################### Keep the whole world singing. . . Dan G (remove the 7)

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Freezeman 22 years ago

Dan,

The crack is about 8 inches from a corner. It is on the side of the structure and 8 inches from the rear wall corner - the thickness of the rear wall. It is as if the rear wall pushed out and took with it the corner. It is a clean break along the side wall. The builder consulted various people who all told him they would leave it as is with the confidence that the poured slab and rebar would hold it in place. However, he said he would feel better doing something with it. So he excavated the dirt away from the corner and part of the rear wall and drilled 5 holes about 18" apart up and down and about 12" from the corner all the way through the concrete filled CMU's - on both sides of the wall. I was there helping and can testify that each of the 10 holes was in a solid concrete area - they took about 5-10 minutes each to drill through with a masonry drill and bit and lots of pressure. We then took a 1/4" thick piece of sheet steel that had bent into a 90 degree angle and placed it against the corner on the outside. It extended from top to bottom of the 8' walls and about 18 inches around the corner on each side. Matching holes had been drilled in the steel and we bolted this steel and some matching steel to the inside of the wall using 10" grade 8 bolts and nuts. The steel had been primed and painted to reduce rusting. We then put some extra primer on the outside and inside pieces of exposed steel. He plans on filling the dirt back into the hole today and pouring the slab next week. The inside area will be prone to rust over time especially being in soil. The outside area will be covered in brick.

I realize I am not an engineer, but I think this should at least help in holding it together. I personally felt like the crack developed because someone who didn't know better was operating a 22,000lb track hoe about 1' from the wall on top of the dirt trying to pack it down as he backfilled. It didn't expand any further over 2 days just sitting there. And no, the footer didn't crack on the inside or the outside of the wall. I am hoping this is sufficient. A couple of people recommended pushing the wall back in place (about 3/4" at the top down to 0" about 2 feet from the base). My thoughts were that doing so would put extra pressure on the bolts and steel after the dirt was placed back against the inside of the wall.

Robert

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Jeff Smith 22 years ago

I don't know the significance of that crack, but realize that concrete pretty much WILL crack, that's why they use seams or expansion material. Find me a foundation that doesn't have a crack in it, I'd be surprised if you could. 1/8" is medium sized for a concrete crack, but unless there is vertical displacement, I usually wouldn't pay attention to a crack that big. If the concrete wasn't cured correctly, or if it was just cured poorly it will crack early on. You should be asking the question, will this crack enlarge and cause a structural problem. Only an engineer can tell you that. If at any time it shows up as a problem and you're made aware of it, you MUST disclose it when you sell. If you don't the significance of a crack in the concrete, you may not have to disclose it, however if a court could prove that you should have known it was a problem, then you could be held responsible. Those kinds of lawsuits are VERY nasty. I would definitely disclose anything I knew to even potientally be a problem to a buyer, it's just too risky not to.

-Jeff

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v 22 years ago

That is pretty rare for residential construction, at least around here.

-v.

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Lyle B. Harwood 22 years ago

? On Sat, 11 Oct 2003 17:25:59 -0400, someone wrote: ? ? ? >Did the builder perform soil testing on various points of the site, ? ? That is pretty rare for residential construction, at least around ? here. ? ? -v.

It's not rare here, particularly when the problem involves a basement wall that is moving. In fact, I just completed a project that had extensive testing and engineering on it- removing and replacing one wall of a basement that was "falling" away from the rest of the house.

To the original poster, best of luck, and let us know how it comes out!

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Patch 22 years ago

By "the house has been closed", do you mean you have already had your closing, before the house was finished? If so, I hope you had a Lawyer involved with the process.

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Mike Dobony 22 years ago

This is a SERIOUS problem as you noted that it will get more serious as time goes by. It sounds like the footing was NOT done properly or the concrete was sub-grade, or there was insufficient reinforcement, and will require a complete removal and replacement to prevent this from getting worse.

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