New floor cracking

[garage-dog]

I few months ago I had a steel building built and just reached the point where I want to epoxy the floor but found that the top layer of the concrete is coming off in spots. I had several paint contractors look at it and each said that more of the floor would come up when pressure washed and sure enough when I had one guy come in and pressure wash the floor a lot more came off. The rep from Sherwin-Williams came to look and recommended shot blasting the floor to remove the top layer and resurfacing the entire floor. What happened? I read in other threads about water curing for 5 days or more and concrete blistering. This curring was not done but it wasn't done when I had an extension built on my house 10 years ago and i didn't have this problem.

 

[PAToyota]

It does sound like the floor dried out too soon. Water curing will nearly always prevent this problem, but sometimes you can get lucky and not have the problem without water curing... Sounds like for the extension you got lucky...