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Fixing crack in foundation

smitch's picture

Fixing crack in foundation (post #207123)

Since I am being flagged as spammer, I will just try to get this thread started then edit the text later. Hopefully my photos will be successfully uploaded. 

Unable to add to this text. It seem ridiculous that my text is flagged when I am a signed in user. I can't add to my text unless I write it, but we all know when a web page gets whacked you lose what you wrote. That's why I type in a doc first and paste!!!

Webmaster, please fix this so I can paste in what I wrote already. Shouldn't a forum be easier that fixing my house?

Ok I see you've increase the cache for this post and it awaits a moderator's approval. Waiting for the detail to post...


 Sorry, didn't access this (post #207123, reply #2 of 18)

 Sorry, didn't access this forum before, so I may have proceeded stupidly in this "project" that maybe I shouldn't have taken on myself. In the interest in saving money for now, I decided not to fix my 6 ft foundation crack on the outside just yet, but proceed on the inside.

After slapping hydraulic cement on the bottom ft, I paused to reconsider. I came upon epoxy injection as a method, but the work I've already done may have made this approach now impossible??? (except on the outside at a later time).
After discussing with home stores and others, I came to believe I should insert some Drylock product that comes in a caulk tube first, squirt and push that into a widened and deepened crack as I've chiseled the small 1/8in crack to about 2 in - 2.5in deep and then pack in hydraulic cement over that. 
The crack extends to the top of the bathroom framing and beyond. So someone suggested that I cut a section of that out and then go all the way up. I was hesitant because of the electrical box/fixture mounted on a 2x4 there but I was told it is far enough away from the wall and not an issue.
I could use a lot of advice I think. Any help would be much appreciated.

smitch (post #207123, reply #6 of 18)

That's one heck of a "crack".

Fill in the pertinent info about the house-age, etc, detail the foundation, drainage etc.


A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


 The house is about 43-45 (post #207123, reply #8 of 18)

 The house is about 43-45 years old. The crack was simply about 1/8 in all the way down 6 ft. I expanded it with expectation that it would give hydraulic cement more to "bite" on. On the other side of this crack at the top is ground level  but the crack from outside is smack in middle of a concrete block that's sidewalk. Adjacent to that is the concrete step with about 4 steps that lead up to the first level of the house. On the other side of that concrete block is a strip of ground surrounded by sidewalk. Enclosed are a number of bushes. That land is relatively flat and so probably doesn't drain correctly, but I really can't speak on that with authority.

What more detail do you want on the foundation?

As cracks go (and given the (post #207123, reply #11 of 18)

As cracks go (and given the fact that you've already chiseled it out a fair bit), that doesn't look too bad.  The two sides have not shifted in/out or up/down relative to each other, just pulled apart.

Do you get any water through the crack?  If it's not leaking then it probably needs no remediation from the outside.  If it's leaking then hydraulic cement probably won't be a complete fix but will reduce the problem significantly -- a complete fix would require excavating the outside.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

  A small amount of (post #207123, reply #13 of 18)


A small amount of annoying water does come in. I figure I can stop this this winter with the inside fix. But should I attempt to go the entire span on the crack? To the top past the framing?

Do note that if you paste in (post #207123, reply #3 of 18)

Do note that if you paste in text rather than typing it in that makes the spam "filter" more suspicious.  (The thing is remarkably stupid, and lets all sorts of real spam through, while blocking many legitimate users.)

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(It's not clear from your (post #207123, reply #4 of 18)

(It's not clear from your pictures whether your question is about masonry/plaster repairs or you've got some plumbing issues.)

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

The issue (post #207123, reply #10 of 18)

Not plumbing, I removed the plumbing where the crack needed exposure for inside access.

smitch (post #207123, reply #5 of 18)

I'm no webmaster, just a dumb carpenter that they stuck a hammer by my name.  I tried to edit your acct. and hope it helps you to post on this dumb software .

Best of luck.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Web stuff (post #207123, reply #9 of 18)

Not your fault and my comment was about function, not person. So thanks.

You have a stress crack in a (post #207123, reply #7 of 18)

You have a stress crack in a poured concrete foundation. You will have to dig outside to expose the entire crack, clean out the loose stuff and pack the crack full of a hydro cement product like Waterplug and trowel off the surface smoothly. Once set up, you could just use a paint on foundation water proofing tar or you could use one of the newer waterproofing membranes. Inside, also use the Waterplug. Mix it loose enough to work deep into the crack but not so loose it runs.

You need to determine the cause of the crack. Can't tell if there is a step down in the foundation to the left of the open area. Often it's a leaky gutter, wash from a roof or other source of water, particularly with absorbent backfill soil, frost can go deep and lift or push. Poor perimeter drainage can undermine the footing if water accumulates in that area. Sometimes with a step down, the difference in the weight of the wall will cause a shift. Something has settled or lifted, it could have been a footing or section of a footing that wasn't sitting on undisturbed earth. 9 times out of 10 it's water that causes a weak area to settle or lift, I'd look for that since it may be remedied easily.

Beat it to fit / Paint it to match

Your explanation is a  little (post #207123, reply #12 of 18)

Your explanation is a  little beyond me regarding drainage. But I will maybe need to find someone who knows such things. I plan to revisit the outside for repair in the spring. Meanwhile I work on the inside. So you see no benefit to first filling with Drylock caulk as well?

I should have mentioned  - (post #207123, reply #14 of 18)

I should have mentioned  - this house is a Twin. Across from my steps is another similar house with the crack in the exact same place. They dug out and patched it this past summer. My attached neighbor doesn't have any leaks so assumes she doesn't have the issue.

I got a 5 gal qty. of (post #207123, reply #15 of 18)

I got a 5 gal qty. of hydraulic cement from Home Depot that you're supposed to mix with water. I Googled Waterplug and I see it looks just like an old product I remember Drylock used to make - premixed Hydraulic type cement. I don't know how these types of products compare, but they seem to be made for exactly the same purpose. Any comments?

Without getting technical, a (post #207123, reply #16 of 18)

Without getting technical, a number of manufacturers make a cement product designed for situations like yours. The products have an additive that makes the cement expands as it cures, rather than shrink like some other cement products. It's often a dry tan powder looking product that you mix with water. It sets up pretty fast so you want to mix small batches that you can work within about 15 - 20 minutes. Once cured, it's waterproof. Drylock, Sakrete, Quikcrete are some brands.

Concrete doesn't just crack open for no reason. It's aguable in certain situations but not likely in yours. Something has settled or lifted, even though that movement could be very slight. Concrete has little tensile strength, so even slight movement can cause it to crack. In many house foundation cracks, the cause can be traced to water soaking into the soil around the exterior. This is one of the reasons gutters are used on houses with downspouts that direct the roof water away from the foundation.

Certain conditions can cause more water to be deposited in specific areas. It could be a valley on the roof, a leaky gutter, a downspout that doesn't have an extension carrying the water away. Go outside and take a full picture of your house and there will likely be some condition that deposits water near your crack. That's not to say other issues could have caused the crack. Many of these are not fixable without serious work. If the crack doesn't keep enlarging, don't worry about it. If there is a source of water, try to mitigate it.

You cannot fix a crack from the inside. Water leaking in will effect the interior patch you are doing now. I've fixed more than a few cracks and never used anything but the Waterplug, Some I've fixed have lasted 30 years.  I've always used a bituminous foundation waterproofing, tar like coating, since the new membranes are fairly recent and I haven't had a reason to use them. The Waterplug, or whatever manufacturer you use, will be waterproof on it's own but the coating is an extra precaution and recommended.

The important part for you is that the crack and water coming in, no matter how little, cannot be fixed from the inside. You are wasting time and materials and may make more work later on when you do dig outside. I can only see one post when responding on this forum. I think you mentioned a stair near the crack. This could be a concern with digging next to it, if it's a concrete stair. Without a full picture of the exterior conditions, it's just a guess as to what precautions you may have to take if digging outside. Nothing you do on the inside will last long. Lots of folks will tell you they have some sort of caulking, you see the sprays advertized on TV and other product claims, they are false, don't believe them.

Beat it to fit / Paint it to match

Thanks. I didn't expect a (post #207123, reply #17 of 18)

Thanks. I didn't expect a permanent fix from inside. Just a stop gap in the short run. I don't really see how this can make things worse but maybe you can elighten me as to what you allude to. I forgot to mention - there are no gutters except in back of the house there's a downspout because it's a flat roof. Don't see any unusual reason for more water except that maybe more pools due to the steps funneling water right down to the pavement below, but that would seem likely everywhere you see such a design.  Don't know how common this is, but I heard many of my neighbors having the same construction and same builder of course, have the same problem.

Regular concrete, as you say, (post #207123, reply #18 of 18)

Regular concrete, as you say, shrinks as it cures.  The OP states that the crack was about 1/8" before he chiseled it out bigger.  1/8" is a pretty small crack and could easily occur in a reasonably long wall as a result of ordinary shrinkage -- there need not be any further mechanism at work.

No doubt it would be preferable to seal from the outside, but there's no great harm in patching it from the inside, using hydraulic cement.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville