Hi Julie,

It's called scaling usualy happens within the first year... a few reasons which can cause that, freezing and thawing of the water in porous non-air-entrained concrete... Another reason is what they trying to tell you, is when de-icing salts used which contain ammonium sulfate or nitrate that could cause that... Another reason could be, it depends on when the concrete was poured, concrete needs a minimum of 30 days to air dry before it can be exposed to freezing.

If the concrete was poured during warm weather, excessive and early drying of mortar in the concrete could also cause scaling.

There could be a few other reasons and let's not forget it could also be faulty workmanship...

That said, is this all over the slab or only in a few spots here and there? Can you post a picture of the entire slab?

Also when the driveway was done, during warm or already cold/freezing weather?

I thought this was going to be another discussion about the neighbor switching garbage cans.

@Mark Bischak, Architect Too early to tell :-) They have only been in the house a few months, give it some time and this could be another topic :-)

I miss garbage can guy.

I wish I had some advice and I'm glad GN Builders did.

The other comments refer to a legendarily entertaining thread. Gosh, that was a great thread.