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Repair cinder block wall cracks ?

Post in 'DIY and General non-hearth advice' started by Pallet Pete, Mar 23, 2013.

  1. Pallet Pete

    Pallet Pete Guest

    I have a wall in my garage that has a large crack about 1/4 on the bottom and 1/2" on the top of the wall in a line from the floor up. A previous owner sprayed foam into the crack and pasted concrete over it so now its leaky. It has not grown any larger since purchased the house 6.5 years ago. how do I go about filling the crack ? My idea is to put a board agains the inside or outside and pour mortar or cement in to fill it and then close up the oposite side and let it dry. Does that sound like the right way to fix it ?

    Thanks
    Pete

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  2. brian89gp

    brian89gp Feeling the Heat

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    Read about re-pointing or tuckpointing. Grind or chisel the mortar out to double the depth as the height, spray the blocks down with water, then pack it with new mortar. If your not handy with a pointing trowel then rubber gloves and your fingers will do a good job.

    Use mortar (Type N or Type S), not concrete. Concrete does not stick to dry concrete. Mortar has lime in it which makes it sticky. Mortar is also pretty thick so you won't be able to pour it.
    Pallet Pete and ScotO like this.
  3. greg13

    greg13 Feeling the Heat

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    My first concern would be Why did it crack? You may have a support issue that requires some attention
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  4. Pallet Pete

    Pallet Pete Guest

    The garage had a very bad roof on it with really bad supports bolted into the walls but none to the floors when we bought the house. We had a new roof with proper supports to the ground so the walls are not holding the weight on there own. It is a good span across with a lot of weight. The structure is fixed now.

    Pete
  5. jdp1152

    jdp1152 Minister of Fire

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    Google multiport epoxy injection kits. Used two last year where a 1953 foundation met a 1973 addition foundation. Haven't seen a drop of water in the basement since then. The injection material varies depending on your need (ie waterproofing vs adding structural integrity).
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  6. schlot

    schlot Minister of Fire

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    Pete, is this an above grade wall or basement wall below the garage? Does t h e crack follow mortar lines? Is the wall out of plane or bowed? Can you snap some pics of the crack and the wall?
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  7. Pallet Pete

    Pallet Pete Guest

    Thanks Schlot I will take some today and put them up with some explanations of the issues.

    Pete
  8. ScotO

    ScotO Guest

    Pete, get us some pictures of what exactly you have going on here. I've got some masonry experience, and it sounds like this may possibly be a place to do some tuck pointing/filling with a hydraulic cement or something else. One think for sure is that it IS repairable, so that's not the issue. Sounds to me like you already got the structure that was responsible for the crack repaired.....
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  9. Pallet Pete

    Pallet Pete Guest

    It's above grade separate from the house garage. It originally was a carriage garage back in the 1920's for horse and buggy but someone converted it along the way to a actual automotive parking garage. The block walls need to be painted badly to seal them if that crack is fixed and the walls sealed it has a good long life left ahead of it.

    Pete
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  10. Pallet Pete

    Pallet Pete Guest

    I will get picks up tonight which explain a lot. Right now its amazing outside and I have to go out and enjoy the sun and warmth lots do right now.

    Pete
    ScotO likes this.
  11. Seasoned Oak

    Seasoned Oak Minister of Fire

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    A long block wall should have expansion joints every so many feet ,i believe it is every 12 -16FT. If not expect some hairline cracks. 1/2 Inch sounds like a settlement issue.
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  12. Pallet Pete

    Pallet Pete Guest

    Thanks guys hear is the picture of the crack Its actually 2 cracks.

    Pete

    Attached Files:

  13. ScotO

    ScotO Guest

    Pete, I'd gouge out the mortar in the old joints (or use a grinder with a masonry blade to remove it) and gouge the crack a little bit, and repoint that. While you are at it, it may pay you to repoint some of the other block in that wall (looks like loose mortar in other areas). Then, I'd be thinking about parging it with cement, or covering it with siding or something else.....

    It's not going to be a real bad job. Once you get the hang of 'tuck-pointing', its kinda easy actually. I'd focus on doing one side at a time (either outside or inside). don't try and clean out both sides first. Clean out one side, point it, and then go to the other side and clean it, then point it.....
  14. Pallet Pete

    Pallet Pete Guest

    Thanks Scotty ! I don't have the money for much more than tuck pointing and paint right now so I will most likely use dry lock. That stuff is tuff as nails in my experience. I will take your advice and tuck point the whole wall where needed too. Its going to be out side this year so the rain will stop getting the inside of the garage wet first.

    Pete
  15. schlot

    schlot Minister of Fire

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    I agree. Looks like a candidate for re-tuckpointing, as the wall looks to be in pretty stable shape.

    If you look down the length of the wall does it bow outward or inward?

    Usually I'd recommend doing the repair and then watching the repair for a year before covering up. That way you can get an idea if the crack is growing again.

    I'd definitely check that the clay tile along the top of wall is mortared and weatherproof.
  16. jdp1152

    jdp1152 Minister of Fire

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    Do not use Hydraulic cement on if you have a block wall. It expands as the reaction occurs and can destroy a masonry block in no time. Trust me on this, I learned the hard way and had a mason laugh at me. It's very similar to spraying the big crack cans of foam into a small crevice around a window. It warps the frame and bam...the window/door won't open. I know this from experience too unfortunately.

  17. jdp1152

    jdp1152 Minister of Fire

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    Seeing the picture now, just have it repointed. That's just failing mortar. What you should do is check to see how plum that wall is before doing any work on it. Definitely nothing that would require epoxy injection.
  18. jdp1152

    jdp1152 Minister of Fire

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    the better question is how in the heck is that leaking? Raining sideways for days on end? I was thinking below grade.
  19. Pallet Pete

    Pallet Pete Guest

    It leaks because the crack goes all the way through the walls. the roof is a low pitch inset roof that sits inside the block with roll rubber for the top. Believe me when it rains it leaks ! it is more than just mortar the wall did shift a long time ago because the idiot that did the old roof didn't anchor it properly so all the weight pushed back on the back wall of the garage. That was one of the issue's we fixed. The other reason is its old block wall and block absorbs moister so it soaks through the block when it rains. I don't see a bow in the wall. What would need to be done if I find one though ?

    Pete
  20. jdp1152

    jdp1152 Minister of Fire

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    If it were bowed, I'd get a pro or engineer to look at it. last thing you want is that thing toppling.

    Once repointed, I'd look into an exterior portland cement based water sealant...something like thoroseal. That would keep any moisture from wicking through the blocks. You could also reface it and put a water proof barrier on before your lathe/scratch coat.There are also products that allow drainage behind the new face should any water penetrate. Of course, all of these require time and budget, but you should see marked improvement in both water penetration as well as efflorescence staining on the interior
  21. schlot

    schlot Minister of Fire

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    Like jdp said if it's bowed get a structural or civil engineer to look at it. It's probably a un-reinforced or poorly reinforced wall. Keep it plumb and in good condition it should last a long time.

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