Hello, try self leveling concrete overlay. There info on what to use, where to get it, and info on installing it.

Typical you will need to clean and remove any loose surface then use some sort of bond enhancer between old and new.

If you cover part or the entire surface with the correct leveler you should be able to hide the fix and give it a custom look from stone to tile with acid staining and sealing. Pictures of acid staining.

Good luck with your project.

Charles

I agree with KJK/USA. Lift the offending slab back into place.

Not a big deal, and is likely to be long term or permanent adjustment.

I assume the patio slab was sloped to drain in the first place, and has settled over the years. Also assumed is the slab is not pinned to the foundation (uncommon to pin them together, but not unheard of). If it is pinned, it will not be possible to jack it up.

I will assume this will work, and even though it does not really answer you question about patch material, I will say GA to KJK/USA. This is a better solution. Nicely done!

Thanks guys! I'm checking out all your suggestions...this is probably a common problem. The step in the photo appears to be sitting on the shallow region, and the mud jacking (which is a great solution for some concrete problems) may be awkward in this corner, but I will still evaluate it with a contractor.

This looks like some kind of "stuff" poured into the corner. Different color and height?

What gives?

The original concrete was poured incorrectly leaving a hollow region in the corner where water forms a puddle every time it rains. Nothing has been poured on top of the cement, and the discoloration is due to water stain with a pencil line to mark the perimeter of the puddle.

Thanks. Maybe old salt has the answer.

Thanks! Great solutions guys (GAs given).

Good point! Great advise from all!

I think I will probably do the following (step in corner hinders raising corner of slab with a high pressure base):

A. Clean and prep corner

B. Use the top-n-bond (viscosity that will self-level)

C. Pour cap a little beyond pencil line and around step to raise region slightly higher and improve strength

D. Finish cap surface and blend edge to existing slab

E. Fill a long but small (width) crack (different area) that appears to be stable (last two years)

F. Resurface entire patio and use acid stain, polymer, paint, or other some other material to improve aesthetics (still need help here).

I will post periodic photos to show progress

Thanks again for all your great advise...what an outstanding site. This is what makes the world "tick".

One thing to point out. I see in your photo (post #4) the slab looks even with the grout line at the brick veneer. This indicates to me it did not settle, so my endorsement for mudjacking should be disregarded. When you overlay with thinset, if you go above this groutline it will look funny, as well as create a likely a spot for cracks or spalls to start. If you are careful to slope away from the house, and do not lap the brick veneer, it should look and function fine.

The link for Top N' Bond Concrete patch is:

http://www.sakrete.com/products/product.aspx?ID=TopNBondConcretePatcher

It is distributed by Sakrete.

Good luck

Thanks! Great professional advice! GAs given

What would be the minimum thickness needed for the overlay?

Instructions and application calculator for various thickness; minimum 0.062".

http://www.quikrete.com/PDFs/Projects/ResurfacingConcrete.pdf

In regard to the minimum applied thickness of an overlay, please follow the manufacturer's written instructions. Usually it is printed in the product instructions on the side on the box or bag, but if it isn't there contact them or visit their website site for further advice. Not all overlay products are equal, where one thickness would be acceptable for all; it may in fact not be acceptable for another one.