If you have a cherry picker for motors or you plan on storing something very heavy then 5 or 6 floor will hold up better.
Pouring concrete floor in pole barn.
Concrete slabs are poured either off or on the job site.
Time lapse video of my 40x60 pole barn floor being poured.
The concrete is considered to float because it is totally independent of the building.
I would use a concrete saw to cut out two foot by two foot squares at each column location remove the concrete auger holes as appropriately designed by the building engineer set the columns in the hole per the plans then form and fill with premix around the top of the column to complete the slab.
This can prevent damage caused by a pre mix concrete truck.
There can also be a delivery fee of 60.
Since there are no foundation walls in a pole building a floating slab can be poured inside the poles using the skirt board for forms.
If you are just storing toys lawnmowers and cars in the pole barn then 4 of concrete will more than suffice.
To have concrete poured and finished it will cost 2 52 to 2 60 per square foot for the labor and 2 83 to 3 57 per square foot for the concrete itself.
Time lapse video of my 40x60 pole barn floor being poured.
I recommend a standard 4 floor for most residential pole buildings.
If the walls are open or you have sliding or overhead doors you can use a 2 4 as a form.
It is best to have the shell of your pole barn completed before you pour a concrete slab.
Prior to pouring a nominal 4 3 1 2 actual completed thick concrete slab in building finished graded compacted fill top will be even with skirt board bottom.
The cost of labor to pour concrete is 45 per hour.