Yeah, that curing time really is necessary. New concrete has high alkalinity and high moisture content which will impair paint adhesion. The finish will then fail.

Let it cure. And use something higher quality than the 6 month Rustoleum if you want it to actually last. nothing worse than trying to remove the bits left on the slab so you can do the commercial level that you should have done in the first place.

Yes it is and your epoxy will also have a cure time and I agree find a better quality epoxy

If it were me, I'd wait longer than 28 days. Humidity can affect the cure time. I'd err on the side of caution. What's the rush? The floor will be there for a long time.

We did a professional grade epoxy 20 years ago when we built our shop. It's just now having a few spots come up. This is a hard use environment with an auto lift and all of the hobby restoration tasks that you can imagine, including welding and brake bleeding accidents.

A friend did a DIY HD garage epoxy at about the same time. It lasted until they spilled antifreeze on it. Then it peeled. And continued to peel in patches. Until they couldn't take it any more and had it ground and resurfaced by a Pro. At 3x the cost of ours. Because they had to get all of the old crud off first.

Spend well once. Spend poorly and more multiple times.

NEVER DIY epoxy a garage floor. You'll be calling a professional to redo it within a year.

Thank you all so much for your words. You'll be happy to know we did NOT do the job and we are going to hopefully find a professional to do it for us- per recommendations. The reason for the rush was that we've been waiting 4 years for this garage, live on a farm in the north, and have gravel/mud roads. We are desperate to drive into our garage and go straight into the house

We will just wait until the summer for the epoxy byba professional. Thanks again foe taking the time to comment. To be honest, at first I was a bit put-off with the suggestions of waiting, but the skinny on concrete was exceptionally helpful in changing my outlook.

CanCork floors- we have already purchased Rustoleum epoxy basement formula too, with the plan to put that down on our basement floor. It's an unfinished basement with a concrete slab and no flooring down anywhere. Thoughts on this? We already have it, conditions are ripe per your specs above, and we live super rurally so professionals are scarce in our area.

Sara, Cancork is a wealth of information on flooring. He really knows his s*&*. I'm interested in hearing his reply about the basement surface.

@Sara...You have to find out if your concrete slab has a vapour barrier BELOW the concrete (laid before it was poured). This vapour barrier is common with builds in the mid 90's and afterwards. Some of the EXPENSIVE builds in the late 80's will have had this...but most will not.

So check the age of the home. The basement epoxy paint could work...so long as many things line up. The vapour barrier MUST be in place before the concrete slab was poured. The surface of the slab must STILL be blasted (to get rid of the contaminants). The epoxy will have a write up. It will have moisture requirements. These are normally found ON LINE...not on the can. But read the bucket anyway.

Be prepared to do more work than you ever thought possible. Personally, I would grind down the concrete, get it as flat as possible and float a floor over top and be happy. Or lay a subfloor like DriCore (it can use shims for flatness) and then float a floor over it. Epoxy basement products are low-end and can fail about as quickly as the garage DIY epoxy.

Good luck. See if you can take it back. I wouldn't trust it as far as I can throw it...not without a degree in chemistry and some EXPENSIVE concrete flooring toys (shot blaster, diamond grinder, cement mixer...etc) and a FULL training in how to use all those expensive toys (and a few months of training in hydrodynamics).