Calling Concrete Experts

[morris_mat]

Cold joint with slurry on top.

This or a self leveling topping slab

[manwitaplan]

Shallower or deeper than 1/2"?

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Tell the builder you want the whole area chipped down then have the finish crew come back in with Ardex CP. We use it quite a bit for finishing or smoothing or building up areas.

I am not sure where you live but you can call HD Supply / Whitecap or Fabco or CMC and ask for a sales guy and explain your situation.

[Snowflake Killa]

Looks like it was to wet. I would have it shot shot blasted an use ardex k15 self leveling. I would also do a moisture test they are not that expensive for peace of mind.

[Snowflake Killa]

Pm sent

[BowOnly81]

I poured and tested concrete in a lab for 12 years and agree with a few of these guys. Could be a number of things. Meaning if it was my slab, I’d get a core sample to MAKE SURE it’s only the top 1/4”. If the slump was too high (7-9”, or more Heaven forbid), it could be a structural issue. If they had a water pocket and poured the concrete over it, all the water will rise to the top and most likely get worked into the top layer and become weak like that. If your core sample comes back with at least 3000 psi, then you know it’s only the top layer and can move forward with the high cementicious self leveler. Let us know what you find out.

[Skipshot]

You are going to have to remove the bad concrete, chip it down till you get to a solid roughened surface. After that the surface needs to be clean extremely well so that proper bonding will occur. Then depending on the thickness there are several products that will work. Sika Corporation is a good manufacture that I have used in the past, probably pricier than others but at the top for anything concrete related. I'd be glad to walk you though the process over the phone, let me know and I will PM you my number.

[Budman68]

Tell the builder you want the whole area chipped down then have the finish crew come back in with Ardex CP. We use it quite a bit for finishing or smoothing or building up areas.

I am not sure where you live but you can call HD Supply / Whitecap or Fabco or CMC and ask for a sales guy and explain your situation.

Listen to this guy. ^

Ardex is your cure once chipped up. Read the direction before letting someone pour it and know the product. Expect it to be dusty and I would consider moving out a week or two during the repairs.

Also, whoever layed that tile should be fired. You shouldn't be seeing trowel grooves that large after compression of the tile.

[El General]

I would have it cored in multiple areas to determine strengths and depths of bad concrete. The builder needs to pay for that.

Then score a clean, square line the depth of the bad concrete and chip down to clean concrete within that line for effected areas. Clean thoroughly with water and let dry for 24 hours. Paint it with a bonding material or prime coat, and float with a patching material like the Ardex mentioned above or some other equal product.

[mjhaverkamp]

They make a machine similar to a scarifier that will break the top of the concrete loose, I would have them use that and then the Ardex to repair the floor, hopefully the entire slab is not like that.

[Booger74]

Shep-Patch @ 3/4". Make sure there is a good rough profile, so material can make a strong bond. Make a slurry with the bonder and the powder before pouring the patch out. It is not a self-leveler, so you will have to work the material and finish it. It's a high strength patch that is commonly used.

[Bullseye07]

As others have said, chip/grind off the bad surface and fix using Ardex. It’s not cheap, but it’ll last. I’m in commercial construction and we had a slab get rained on. The surface just flaked off. Ardex was the fix