Cracks in attachted garage floor

[Rmedeiros]

Hi everyone,

Longtime lurker finally decided to join. Not sure where to post this but was hoping someone could give me some insight. I have a question regarding my garage floor slab. Theres a pretty long crack coming from the foundation wall of the house and branches across my two car garage, it splits towards the center and in one direction it goes towards one of my garage door entrances and in the other it fades away before reaching the other side of the wall. I've attached some pics.

I took the pics following the crack on the floor. When my gf parks in the spot where the crack is I've felt the slab move as her front wheels passed from one side of the crack to the other and i was standing with the crack between my feet.

I guess my question is should I be concerned? can I just patch it up and not worry about it? I live in the southcoast region of MA near the cape, so shrinkage is definitely an issue with the tempo swings.

 

[shaun oriold1]

I'm frustrated by the huge pictures, so I'm only going on what I can see on my screen - without scrolling around....

Anything you do to the crack isnt going to change the fact that the crack is there. You can fill it with a flexible filler, which might hold, but it depends on how much the floor is moving. 1/4" of joint compound isnt going to stop 10k+ LBS, and the flexible compounds do have their limits.

A repair will be obvious. So ideally you would cover the floor with something afterwards ( epoxy, or tile)

Look outside the wall, and try to figure out the reason. Do you have a downspout right there pouting water down, and washing away the base material? Poor grading maybe? -OR maybe its just concrete... it cracks.

 

[Rmedeiros]

I'm frustrated by the huge pictures, so I'm only going on what I can see on my screen - without scrolling around....

Anything you do to the crack isnt going to change the fact that the crack is there. You can fill it with a flexible filler, which might hold, but it depends on how much the floor is moving. 1/4" of joint compound isnt going to stop 10k+ LBS, and the flexible compounds do have their limits.

A repair will be obvious. So ideally you would cover the floor with something afterwards ( epoxy, or tile)

Look outside the wall, and try to figure out the reason. Do you have a downspout right there pouting water down, and washing away the base material? Poor grading maybe? -OR maybe its just concrete... it cracks.

Sorry about the pic size, Im used to message boards that resize them automatically, I re-sized them. I have noticed that maybe 15' or so from the side of the house a sinkhole appeared in the dirt I have been filling it but it slowly returns. There has also been a erosion area near the foundation wall near a gutter, about 3' away from it, so my guess is it may be damage due to water erosion...maybe I will look into it further. Thanks for the help

 

[BlackTalon]

If erosion caused voids you may be able to stabilize the slab (once the erosion issue is addressed) by 'mudjacking'. I would sound the slab first by dragging a 2-3 foot length of steel chain across the surface or by tapping on the surface with a hammer.

 

[James-W]

I would think if there is an erosion problem, you need to address that first. Once the erosion problem is taken care of, then you can get to work on the shifting of the floor issue.

I have heard that in many cases mud-jacking works fairly well. Maybe it would be worthwhile to get somebody who does that type of work to stop by and check it out to see if mud-jacking is something that is possible to do in your particular situation.

I guess another option would be to bust out the old concrete and fix the area underneath the garage floor before pouring new concrete. That would probably be a last resort as it would be quite expensive, but it would no doubt fix your problem.

 

[pd59]

I would think if there is an erosion problem, you need to address that first. Once the erosion problem is taken care of, then you can get to work on the shifting of the floor issue.

I have heard that in many cases mud-jacking works fairly well. Maybe it would be worthwhile to get somebody who does that type of work to stop by and check it out to see if mud-jacking is something that is possible to do in your particular situation.

I guess another option would be to bust out the old concrete and fix the area underneath the garage floor before pouring new concrete. That would probably be a last resort as it would be quite expensive, but it would no doubt fix your problem.

+1. If you can feel the slab shifting when a car drives over the crack, you have bigger problems than just a shrinkage crack, and that needs to be addressed first, because that crack is going to show through any epoxy you put down with that much movement. Either the foundation is bad or you have a void under your slab that is allowing it to move like that. Mudjacking would be a solution. I would have a foundation contractor look at that.

 

[Rmedeiros]

Thanks for all the input everyone. I spent yesterday afternoon rerouting the gutter about 6' away from the house. Next step is to get some in hear to check out out. Thanks again everyone.

 

[zporta]

Sounds like that the sub grade has settled and left a large enough void to cause the slab to move. If you feel it moving when 1/2 the cars weight crosses the cracked i would be concerned. Like others have said check out someone in the mudjacking field. But if that doesnt seem like a viable option a total replacement might need to be done. Then have the sub grade properly backfilled and tamped

 

[CNGsaves]

Re: Cracks in attached garage floor

Any big trees nearby whose roots could be under your garage?? Garage have gutters all the way around, and water routed away from foundation?? Pics from exterior perimeter of garage would help.

+1 that mudjacking is likely solution for underslab void.

Would be beneficial to other GJer's to know location so Update your GJ profile with City / State. Might be able to recommend specific companies in your area. Also, if you live in Florida with sinkholes, that would be my first culprit !!