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CMU corner crack through block

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akjose

Mechanical
Oct 8, 2012
5
Need some advise guys. I'm a ME so I dont have much knowledge on this. I have a crack in my CMU wall on the rear corner of my house. See attachment. The house faces uphill. The crack goes just about from top to bottom. Some through the block and some just between blocks but basically a straight line. It feathers off at the bottom and doesnt seem to go to the footing, but it may. It has not moved in the year I have been at the house and it looks like it has no vertical movement. But it is a crack on the corner. At the inside top is cracked all the way through. I cant see the rest of it due to a finished basement.

Possible cause: I decided to clean my gutters yesterday because they were all clogged (front and back). At the base of the crack, the gutter drain elbow was busted. The pipe the elbow went into was busted. Like someone tamped on them too hard and smashed them from the top. Anyway, I dug a hole and found that the front gutter drain terminates at the rear gutter drain and the rear gutter drain terminates at the same place. BUT there is not wye in the piping. I guess whoever did this thought water would flow uphill.

So I am now replacing the gutter drain, rather, adding a gutter drain and replacing the elbows and adding a wye. I have some strong tie epoxy which I plan to use pressure inject in the crack but I am not really sure if that will be enough. the footing looks like it has deteriorated a slight bit from all the water on it. I have no doubt that the pooling water caused more settlment over time. The house is 16 years old and I would imagine this was done with the build.

 
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akjose,
The crack could be from a number of causes. One that comes to mind here is that the wall beyond - heading toward your deck, might have moved "downhill" slightly, rotating the masonry wall at the corner and cracking it. You might want to run some stringlines along your walls to see if there has been any slight bowing, etc.

Another cause might be block shrinkage.

It might be good for you to hire a local structural engineer who can investigate the full features, evidence, etc. on-site.
 
I have seen similar problems many times with settling associated to downspouts that do not take the water away from the house. Do as JAE suggests and enlist the services of a local structural engineer.

Mike McCann
MMC Engineering
 
The crack looks like walls I have seen that were overloaded laterally due to backfill. Is this a basement wall or a foundation wall?
 
Definitely going to get a structural engineer to check it out. In the meantime, I have dug a trench, added a wye and a section of drain pipe to get the water away from the corner. Hopefully this helps as we are getting alot of rain from the current hurricane.

Charlie, It is foundation wall with basement inside. It is a 2-story modular cape cod above the foundation. Sloping lot...if you look in the first pic, it slopes uphill to the front of the house with 4 courses of CMU visible at the front. Supposedly, the front wall is filled with grout. There is no buckling of any kind on the front wall. I wish they would have filled all the block with grout. Here is a pic from the front corner (taken to the left of the first pic).
 
 http://files.engineering.com/getfile.aspx?folder=0f1da423-64db-4b20-be89-5b997839e307&file=front_corner.JPG
From my armchair it doesn't really look like differential settlement due to erosion or consolidation for example. As I say, it is more like damage during construction. If there is a top and middle horizontal bond beam (grouted and reinforced) then this can go a long way toward forgiving that kind of damage. But you are probably lucky if you have a top course bond beam. A structural engineer will be able to tell you if it is alarming and what repairs are needed. It should be pretty straight forward if there is no backfill soils directly behind the cracked wall (just the basement living space). It will probably involve epoxy injection of the cracks and possible retrofitting a bond beam at mid-height. Again, just an armchair opinion :8)



 
How recent is the crack... or was it just noticed? It does not appear to be pristine and appears to be many years old.

Dik
 
We bought the house 11 months ago. Crack was there when we first viewed the house September of last year. Wife wouldn't go for an engineer because of fee. It has always been on mind but then I found the stupid gutter drain system that makes me worry. Especially if the gutter was put in 16 years ago with construction of the house.
 
I don't think, based on your photos, that the crack is due to settlement, or that it is related to drainage issues. More likely due to movement in the floor structure above, and because the wall is not reinforced, it doesn't take much to crack it.
 
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