[NuBota]

Will probably catch flak - but I agree with Pat g in terms of doing it all in increments - especially for your application.

In my first house when I was young and poor, I poured my 12x24 @ 4" patio by hand. Had a boss that would let me bring left over material home from our jobs. So at the end of each day I would shovel left over sand, gravel into my little S-10. Extra bags of portland I could take as well. After a few months I had enough material (had to buy a few bags of portland) - and an old 17cf mortar box and mixing hoe

Anyway, poured two slabs 12x12 a week apart - each took about hours - had my old man helping. Good solid base (had the area framed and prepped for months), 6mil plastic and wire mesh. Was in the house 13 more years with it - cold joint never opened up - no cracks. This was my first time ever doing it - I didn't lay mud on the job until AFTER I did this project. Was in the old neighborhood few months ago and it still looks the same - no cracks or shifting - 20+ years now.

Used a 12' 2x4 to screed/tamp and then just hand mag float and finish
trowel. Did a glass finish (just to see if I could) before brushing

I am doing the same thing as N80 - gonna build the barn with dirt floor - then decide how to handle floor later. Am thinking about doing it the same way since I don't like the pressure of getting it done fast with the truck on site. Buddy of mine got lime poisoning doing the footing for his garage - was rushing to keep up and mud went down in his boots - boy could barely walk for weeks.

Not negating all the good advice here - if I was building a garage or house - I would have the pros do it - I just need a level area to change implements. Over time could extend into a complete floor useing Pat's advice