How old is the slab? How much grinding did they do?

Planipatch requires mixing. Mixing means measuring. And measuring can go wrong. One decimal point and you have Planisoup. When the patch material is delicate (as you describe) it often means it was not mixed properly....as in too much water or the wrong temperature or the wrong...something.

Feel free to look at the application directions below:

3000515-planipatch-en.pdf (mapei.com)

Now to do the math: How many square feet did they work on? How many bags of Planipatch did they use? Have you explained to them the issues with the surface?

Thanks for the reply. It was about 1300sf on a 20 year old concrete slab. They used 14 bags and a gallon of planipatch plus.

The guy who did the Leveling does Hardwood installations for Lowes so I figured he knew what he was doing. He recommended the product so I assume he is familiar with it and has used it before.

If they coated 1mm thick then they can get 12sf per kilogram. I'm assuming they used 14x 20.5 kg bags (45 lbs). At this thickness they can achieve 3427 sf of coverage. That's a bit too much coverage.

If they coated 3mm thick then they can get 3sf per kilogram. Assuming the same numbers as above (20.4kg x 14 bags = 285.6 kg). That means they can cover 856 sf. Hmmm, not enough.

Split the difference (2mm thick) and you get 1736sf. That's closer. Now for the mixture.

*Diluted Planipatch Plus: 1part 'plus' to 3 parts water (for a total of 4 parts).

1 gallon of Planipatch Plus = 4 gallons of Diluted Planipatch Plus.

4 gallons of Diluted Planipatch Plus = 640 fluid ounces (oz)

Right. Now for the big numbers:

1 kg of Planipatch requires 10-11 oz of water

Therefore: 285.6 kg requires 2856 oz of liquid

1kg of Planipatch requires 11-12.5 oz of Diluted Planipatch Plus

Therefore: 285.6 kg requires 3570 oz of Diluted Planipatch Plus

To put it another way, the 640 oz of Planipatch Plus will mix (properly) with 51.5kg - 58.2kg

51.5kg PlaniPatch = 309 sf (depth of 2mm)

58.2kg Planipatch = 349.2 sf (depth of 2mm)

Whew! Isn't math FUN!?

It looks like they went pretty thin on the coating and didn't use enough Planipatch Plus. They needed 5.5 gallons of the Planipatch Plus to work it as Diluted Planipatch plus.

So far, I've found ONE issue with mixture. It's up to you to find out if the messed up the WATER amounts as well. Seeing that they messed up the dilution process, it is highly possible they messed up the total liquid amount...

To give you an understanding of what is involved, it took me 45 minutes to work out the math. I LIKE math. Imagine someone who does NOT like math. It could take upwards of an hour or more to get this right. Now imagine how much time a flooring installer wants to take to figure this out. Yah. About 5 minutes is the most they want to spend on this process.

Contact Mapei's tech support. Being able to scratch the compound off with your fingernail means there is a adhesion issue. The surface prep may have been unacceptable.