Detached Garage Concrete Slab Cracking

Reply

  #1  
Old 05-14-11, 02:30 PM
Member
Thread Starter
Join Date: Jun 2009
Location: USA
Posts: 15
Received 0 Votes on 0 Posts
Detached Garage Concrete Slab Cracking

Hello all,

I have a question regarding some cracking concrete in my detached garage. The detached garage was added on to my home about 20-30 years ago and there has been some noticable cracking in the concrete slab over the past few years due to the freezing and thawing (I believe) during the winters. The cracks begin the the middle of the garage and go out to each of the three walls and the garage door. The cracks are uneven (meaning one part of the crack is higher than the other) by about a quarter inch. Also the cracking is noticable from the outside of the garage, since my backyard slopes down and the concrete slab is visible from the outside. I can tell the cracking goes all the way down, deep into the slab. (This is noticable at two different points). Further, the cracked slab exits my garage door where it widens to about a half inch.

So my question is, is what do I do? I don't know if just patching the cracks with cement patch will work (I assume the cracks will resurface in a year or two if I do a surface patch). Is it possible that I am able to "inject" some sort of cement bonding agent down into the cracks? Could that do the trick? Or is the only hope to put in a totally new cement slab, which would mean tearing down the garage and spending lots of dough in doing that?

Any help would be appreciated.

Thanks in advance,
James
 
Sponsored Links
  #2  
Old 05-14-11, 02:41 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Received 3 Votes on 3 Posts
James, was there crack joints cut in the slab when it was poured? If not, you are getting spider cracks which is perfectly normal sans the joints. Cutting those joints tell the concrete where to crack, because I will guarantee you it will crack. Post a couple of pictures of the cracks and let us see what you see. Sometimes cracks appear and stay that size forever. If they start widening, then you got problems. http://www.doityourself.com/forum/el...your-post.html
 
  #3  
Old 05-14-11, 04:12 PM
Member
Join Date: Feb 2005
Location: USA
Posts: 1,396
Received 0 Votes on 0 Posts
If the cracks are widening and the cracked sections are different heights, then either part of it is sinking or the other part heaving. Sinking would be a better guess.
Call a company who does slab jacking. You'll find them in the yellow pages under concrete contractors. It may also be termed "mud jacking" there. They will pump a lime slurry under the slab to raise it to the same level. The slurry will also fill any voids under the slab. Once it's all back to level, I'd fill the cracks with an elastomeric caulk.
Look around for a place (swale?) where water could be washing under your slab, undermining it. If you find such a place, fix it by regrading the yard away from the garage. Good luck.
 
  #4  
Old 05-14-11, 08:32 PM
Member
Thread Starter
Join Date: Jun 2009
Location: USA
Posts: 15
Received 0 Votes on 0 Posts
Hello Chandler,

Thanks for the response. I have tried to embed the image, but if that doesn't work, the link should. It is dark out, so the pictures are super great. (Picture #1 of the 6 is of the side of the garage, where you can see the crack is going down the whole side of the slab).

Anyway, the slabe did not have any joints in the single car garage, but since we bought the house 8 years ago, it seems to me the cracks are widening. You can see from the pictures that the previous owner "patched" the cracks, but that of course has not worked. Pecos had mentioned "slab jacking"....do either of you know how pricey that is exactly for a single car detached garage?

Thanks once again,
James


[IMG]Pictures by Paige801 - Photobucket[/IMG]
 
  #5  
Old 05-14-11, 09:17 PM
Join Date: Mar 2005
Location: USA
Posts: 6,130
Received 0 Votes on 0 Posts
You said a "garage was added on to my existing home that was built 20-30 years ago".

A better description could help. A detached garage slab that was added to house is hard to understand and reason with. Was it built to the same frost levels as the home and actually attached to it? Since you are apparently in IL frost could be a factor.

What is the construction? - An isolated floating slab foundation or a floating slab poured between stem walls and supported by the stem walls.

Since it had shrinkage cracks and not proper sawed and sealed joints, water could easily seep in and add to settlement and future cracking.


Dick
 
  #6  
Old 05-15-11, 04:49 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,967
Received 3 Votes on 3 Posts
You'd just have to call around and get several quotes on mud jacking. It does appear, after re-reading your OP, you have stem wall or footing settlement, since the cracks start in the middle and spider outwardly. Once the cracks started, bringing in snow and water didn't help, as it would melt/run into the cracks and, in your winters, it would freeze causing separation to a degree. I believe the jacking is your only solution. If the cost is prohibitive at this point, at least fill the exiting cracks with an elastomeric caulk. It will stretch and contract with the weather, and will prevent further water infiltration.
 
  #7  
Old 05-15-11, 09:01 AM
Member
Thread Starter
Join Date: Jun 2009
Location: USA
Posts: 15
Received 0 Votes on 0 Posts
At a time there was a carport next to the home, but has since been removed and the garage was put in it's place (detached from the house). The slab meets with the drive, which is asphalt. The slab does not acutally attach to the house, so the instructional integrity of the house is not in danger. Dick, I'm not sure what you mean by "stem walls", if you could tell me what that means I might be able to give a better description.

Chandler, thanks for the response....I might as well get it done right and have someone come out an look at it.

Thanks,
James
 
  #8  
Old 05-15-11, 06:15 PM
Member
Thread Starter
Join Date: Jun 2009
Location: USA
Posts: 15
Received 0 Votes on 0 Posts
My fault Dick, the house was built in 1956, with the detached garage being 20 to 30 years old.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: