cinder block garage cracks

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Old 10-30-15, 08:36 AM
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cinder block garage cracks

I have a freestanding hollow cinder block garage which was most likely built in the 1940's. When i moved into my house 10 years ago i noticed some cracks around the windows and also noticed that there were NO gutters! When it rained, it would just pour down the sides of the walls - one of which has a poured cement sidewalk (which was totally cracked and pitching up - and water was getting in between the cement and cider blocks).
I put gutters on the garage and had the poured cement area repaired and re-poured.

I do have to work on the grading in the front of the garage as it's a bit low - but i have started to see the original crack get wider within the past year or so (after i had the cement area re-poured). The mason who did this, was using a jackhammer and within this year, the back alley that runs behind the garage was re-done and they were using huge tamping machines. I am thinking that some of this caused the cinder blocks that have always been cracked to shift.

I put a level up to the bottom part of the wall and that is level - but up above where the crack is - is actually shifting inward (towards the inside of the garage) a bit. In fact, the bottom part is probably 1/4 inch forward from the top.

I explained the problem to a mason (without him looking at it) and he said he'd make a channel in the inside of the garage vertically through the blocks and then put a piece of rebar inside and cement it in.

I am sure that this is due to foundation issues - and perhaps some of the vibrations happening from the jackhammers - but i am wanting to try and stop the crack! Does anyone have any other ideas or suggestions? Or does anyone know why a cinder block wall would shift in like that?? I would think the bottom part would be the one out of level.

any thoughts would be greatly appreciated!

Here are some pics:

from the outside (crack at top is 1/4" inwards) https://www.dropbox.com/s/h09jbzxti2...59.37.jpg?dl=0

another view from outside: https://www.dropbox.com/s/hiybxl25vn...00.03.jpg?dl=0

from inside: https://www.dropbox.com/s/x6qoxadfsg...58.37.jpg?dl=0

the other sides of the garage have a few small cracks that have been there and remain the same.
 
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Old 10-30-15, 09:14 AM
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Pictures don't load. Get error message "We can't find what you're looking for."
 
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Old 10-30-15, 09:23 AM
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Old 10-30-15, 01:38 PM
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pics --->

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sorry - here are the pics attached
 
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Old 10-31-15, 07:01 PM
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The prevalence of stair-step cracks, located close to a corner, tells me that the problem is being caused by excess footing settlement at that corner. It could have been made worse when the alley construction (vibration) activity took place. If I was in your position, I would do a bit of exploratory investigation at the footing in that corner, digging down along side of the concrete to see what the underlying material is composed of. Talk to your local AHJ to see what their take on the situation is--who knows, there might have been other damage claims resulting from their work in the alley. If that's the case, they should be responsible for repair costs.

Proper repair would normally consist of installing a few helical piers at the corner, to lift the corner after proper bearing is achieved. Trying to seal the cracks without doing anything else will be a wasted effort. The rebar-in-the-wall trick might help, but it's unlikely to stop additional (major) settlement from causing more wall damage.
 
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Old 11-02-15, 06:49 AM
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what is your take on this??

bridgeman - thanks for taking the time to respond i appreciate your advice. It does make sense but i want to get your take on someone else's comment from another forum:
Pretty common step cracking for a 75 year old building. I highly doubt it was caused, or escalated in any way, from a plate compactor or air hammer being used in the vicinity. It's generally caused by the the expansion of the steel angle over the window as it rusts. The block is less forgiving, and the top of the windows is definitely a weak point in block work, especially when it's that close to the gable.

You could have a cell or two grouted with a light rebar, or just have it chipped out and tuckpointed. Either option is likely to extend the life of that garage beyond yours.......
There is rust on the lintel, but what you said also makes sense too. If i investigate and dig down at the corner, what should i be looking for? More cracking, how deep the foundation goes? The stair stepping cracks are at the corner but they also extend from the window so I'm not sure if this is a case of the lintel and the corner foundation or just one. Anyways i just wanted your thoughts about what the other guy said... thanks in advance for any input!!
 
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Old 11-03-15, 05:24 PM
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I'm not going to judge someone else's opinion from another forum--don't even think it's legal, and I don't want to get blacklisted by this forum's moderators for doing so. However, what the MGFOF (mystery guy from other forum) said definitely has merit, although I don't think that much cracking could be caused by pure lintel corrosion. Especially since there are no visible rust stains showing on any (pictured) wall surfaces. Contrary to what MGFOF said, "chipped out and tuck-pointed" will not appreciably extend the life of your garage.

I have personal experience with the damage caused by pack rust and corrosion expansion, when one of my NM DOT concrete box girder bridges had the entire end span raise up almost 3/4", the result of heavy corrosion of the 3 solid steel bearing rockers supporting that end of the bridge. And the heavy breast wall rust stains in front of those bearings were visible from several hundred feet away.

Investigating the footings and bearing support would normally involve determining the footing soundness/condition, depth and whether there's any evidence of organic material or fines working out from under the footing.
 
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Old 11-04-15, 10:52 AM
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arming myself with knowledge

hey bridgeman - i understand completely and don't want to get you penalized for anything. I think it's important to get a few points of view especially before i bring in a pro to give me an estimate. I can't tell you how many times I have had well-researched and highy rated contractors mess things up. I do as many projects on my house as i can because i actually care about solving the issues for the long run and not putting a band aid on a gaping wound! There is actually rust but not running down anywhere. The cracks have been there for years and i just thought they were minor, they never changed at all and everything seemed fine. It was after the work on the road in the back and along the side of the building when i all of the sudden took notice of the blocks shifting. Don't want to ignore it and I very much appreciate all of your input. Now to find a good contractor
 
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