For 20 years I've been waiting for all the planets to align and allow me to put a concrete floor in my barn... 6" thick, 1/2" rebar on 18" centers, 15 mil vapor barrier. I want to be able to drive any machine inside that will fit through the door!

The pour for the 1st stage starts bright & early tomorrow morning

It would have been a lot simpler to make the slab before the barn. Kind of like putting your underwear on after your pants. But the building was already up when I bought this place... and I have so much junk, and no place to store it, that it was simplest to do the center first. A new slab and 40x60 shop just isn't in the budget and I have waited long enough.
My four-post lift has been in the crate for several years now. You can see it off to the left side.

Next step is to move all the junk onto the slab once it's cured, then do the same prep on the full-length narrow strip and the other square section.

Have you thought about putting a covered out let under your lift this would be a good time to put conduit and a plug under it.

You'll be impressed with how much heat the concrete gives off while curing.
Leave some windows & doors open, and run a fan too, if at all possible, to move the moisture.

Good for you, I see too many people opting for a 4" (3 5/8") slab to save a couple of bucks in material then later regretting it.

The longest journey begins with a single step, enjoy the trip on finishing your shop
I went through a similar process on my pole barn to make it into my shop

Yep... compared to the cost of labor, a few hundred extra for a true 6 inches of 4000 psi concrete is well worth it. Tractors and a backhoe will be driven on it (not on the 4-post lift, just the floor!)

Phase One complete! Now it has to cure for a while so we can start on the six foot strip to the right. Since my friend doing the prep wants to do as much as possible with his 'hoe, waiting a while is prudent. Either that, or we have to hand-dig the dirt in sticky southern Missouri heat...

Cool. About 1/3 of my pole barb is finished and has a cement floor, the other half of it is still gravel. Before I ever did a floor in there I'd probably pour a slab outside first to have some more space to work on stuff without having to pull stuff in and out. Of course that will probably lead to wanting to put a roof over it and if there's a roof it's not much more work to wall it in....

Good job on the rebar on stands! Too many get cheap and don't use stands or even worse use chicken wire not realizing the weight of the concrete will sink it to the bottom and defeat the purpose. I always pay a little more and have them add extra cement to mix. Makes for a stronger floor or driveway.

Any thoughts on epoxy coating the floor? It'll never be easier to prep than when it's new and clean...

I can get this at Home Depot although it is likely to take two orders, after reading the reviews.
https://www.homedepot.com/p/Rust-Ol...ndustrial-Floor-Coating-322759/302690075

Looking good, Doc. Garage journal is probably your best resource for floor coating research.

Here's a youtuber I follow that applied that to his existing shop floor recently. https://www.youtube.com/watch?v=75NrKtnqjHA

This is the first of 3 episodes. The first vid is mostly prep work but does start applying the product starting around the last 4 minutes of the vid.

Good luck with the project!

I thought you were talking about a magazine at first... but that would not be anywhere near the oddest

Anyhow I've been browsing that forum and it looks like Armorpoxy would be a better choice than anything from a box store. Their"Job on a Pallet" with everything needed is $1500, but Garage Journal forum members get a 15% discount. Guess the price of the man-cave just went up a bit more

I did one of mine 14 years ago with plain rustoleum epoxy shield, it has been flawless. I waited 28 days, etched with muratic acid, and rolled it on. I am sure any brand is good but have had friends buy the high dollar cool guy coatings, and super clearcoats and they have problems with hot tires sticking to it. I will warn you that my paint will burn from weld slag, will come off if you beat on it with a hammer, will lift if you put lacquer thinner on it overnight, but that should be obvious. I have another shop with plain power honed super smooth concrete and I like it too, it has stains but as long as you wipe stuff up it is no problem either. I did not put plastic under that slab, 21 and did not know any better, so no faith the paint would stick. My painted floor was power honed, but not as smooth as my non painted. If yours is super smooth have someone shotblast it. The paint is slick when wet, I put rustoleum silica in at 1/2 the recommended amount for a little grip. If you overdo the silica it becomes a [censored] to clean. I think my next floor will be medium honed and concrete stained that brown rust color.
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If you're going to be driving equipment in there and doing heavy work I wouldn't spend $1500 on coating. Have the concrete polished and then just put a coat of wax on it. You'll need to redo the wax every other year or so but it will hold up pretty well and it is easy to sweep up.

Interesting suggestion, thanks. But what happens when oil, gas or solvents inevitably drip on the wax? It'll pretty much instantly dissolve (and likely stain the concrete permanently).

A polished floor with wax on it will clean up pretty easily. If the concrete isn't polished then it will stain very quickly. When I worked at Xerox we had our machine shop areas polished and waxed. It was the best floor system that we ever came up with. This was in a machine shop where it was common to spill lubricant and other chemicals. Having the floors polished was the key. Grind and seal is a little less money than polishing. Call a local contractor and get some quotes.

Concrete densifier is well worth a look, and will noticeably help the durability of the slab + will help reduce dust produced by the slab.

Never heard of this stuff before, can it be used on cured concrete?

There are probably different types out there, but the type I used is applied to a cured slab.

These are all good.

https://www.legacyindustrial.net/products/densifiers/

It's used in alot of different ways. Sometimes applied before the slab is put to to work. Other times between stages of grinding and polishing.

It's well worth it, even if you change your mind and apply a coating later....but it prevents spills of all kinds from soaking in.

If you do a coating later on....and the coating ever fails you won't have dust and so on. If the slab has to be ground first before applying the coating, the densifier will give a nicer substrate.

I couldn't think of a reason to not use densifier, other than a slight expense. It's super easy to apply.