Repair for large cracks in floor

[Steve from Socal]

Hi,

I am a new member and have a garage with many large cracks, the slab is actually cracked in two from what I can tell. I live in the San Fernando Valley of Los Angeles and the 1971 and 1994 earthquakes likely started the cracking. I don't have the resources to replace the slab and I have several heavy machines on the floor. I realize that any fix will be subject to more movement but the cracks are getting to the point where trip and fall accidents could happen. The worst crack is in the middle of the slab and it got worse when I moved my mill and band saw 4500 and 2000 pounds over the area. What would you do to stabilize the floor? The slab is 20x20

Thanks,

Steve

 

[Kevin54]

Not much you can do to stabilize it other than replacing or mudjacking. How much difference are there in the two pieces as you say they are a trip hazard? Mudjacking should bring one slab back to the height of the other slab. Also it doesn't sound like you have any rebar in it which would let the slabs move independent of each other. You could always do a skim pour over the top but it would more than likely crack out. Can you post up some pics of the problem area?

 

[AlphaGarage]

There are epoxy products that will fill the crack, but as Kevin54 pointed out it will not keep the floor from future displacement.

If the future shifting isn't too severe then a filler that remains somewhat flexible might do the trick. A filler like Wolverine Coatings IntegraFlex 1921 is a good candidate.

The WCC Technical Data Bulletin about this filler epoxy:

IntegraFlex 1921 Flexible Joint Sealant is a 100% solids, two-component polymer hybrid that will provide a resilient filler for expansion joints. IntegraFlex 1921 has excellent flexibility and provides exceptional adhesion characteristics. IntegraFlex 1921 is recommended for expansion joints in general industry as well as expansion joints of highways, bridges, airports, garages, and marine decks. IntegraFlex 1921 provides an excellent bonding surface for other Wolverine Coatings Corporation products.

 

[Steve from Socal]

I can't show the area that is the worst right now a machine is over it for re-paint. The miss match is about 1/4~3/8 and it is highest at the open end of the slab, there is a stem wall on three sides. The house was built in 1964 and it was tract house with rock roof so no rebar is most likely the case. I will try to get some pictures of some the areas later today.

Thanks,
Steve