I am going to suggest leaving this one up to professional, just because of the scale of the job and the amount of manpower needed to do it right. I have poured a few concrete projects with and without help, even own a small electric driven concrete mixer. The largest project I was directly involved with involved repairing a broken / sagging driveway section, about 12x12 feet, including jack hammering up old concrete, etc. This one had concrete delivered, about 1/3 of a truck load as I recall, and still involved a full day a labor to prep and frame. The next smaller project I did used sack crete mixed on site, this was building a slab to mount my standby generator and fuel tank on, it measured 4x12 ft x 6-7 inch thick (to support weight and vibration), this project required almost 50 80# sacks of quik-krete, and about 8 hours of labor with 3 people, myself, a retired man who had experience working with concrete while building houses when he was younger, and a able bodied teenager to help with the heavy lifting (who spent most of his time texting), we started at about 8 am one morning, spent the first 2 hours with prep, framing, stacking out steel mesh, etc. Then began the mixing and pouring at 10 am, we then spent the next 5 hours mixing and pouring sacks of pre-mix as fast as we could to prevent the base from drying by the time the next sack was mixed and ready to pour. It would have been easier if we were using smaller sacks, or a larger mixer as this little mixer was limited to 50 pounds at a time, so each sack had to be divided into two batches, so we ended up mixing and pouring about 50 pounds of concrete every 3 minutes for 5 hours, add in time to rake, stir, tamp out air bubbles, etc and it was non stop work. Once we were finished pouring there was still another hour or so worth of work left to do (mostly with the help of the retired guy) levelling and broom finishing the surface, a task far more tedious than I would have ever expected on a little 4x12 slab.
Ike
