Hoist Concrete Thickness Requirement

If you planning on installing a 2 post hoist in your shed. and your slab is a few years old or just 100mm concrete with steel reinforcement. I think this slab is up to handling the hoist.
How do I test to see the compression strength?
To be safe a 2 poster would require a special concrete pad installed that would add to the cost. In A  garage you only have a standard flat 4-inch concrete
floor and if you want a  4 poster that does not need to be bolted down, In fact, it comes with special casters to allow it to be easily moved by one person and easy to move it around the garage. And It only needs a standard 10 amp power outlet, 240V and you really would like it because it is so stable with the car raised – an important feature. you have no problems getting wheels free when the Hoist is raised, with the hoist raised by using a trolley jack and modified jack stands, so most jobs can be accommodated, even engine swaps or gearbox change.
well guys, finally you need to get a 2 post hoist as your back can no longer handle working on the ground anymore… Now, the problem is my shed concrete is 100mm thick and the 2 post requires the specified 100mm minimum but would rather 150mm and if you have got a lot of different opinions from people saying 100mm is fine then and then you are told that you must cut the concrete where the two posts will be sitting and
pour to concrete additions approx 1 meter by 1 meter by at least 800mm deep
The concrete that you pour should be ideally 30mpa strength, in this case, you in fact would not require reinforcing with steel mesh as long as your concrete strength is in the vicinity of 30mpa. If you are going to be working on expensive cars and the fact you would like to use it for storage as well as working the above procedure will make the hoist and especially where the main load will be acting on ie at the base of the 2 posts this will create a strong and safe working position and environment for your
self and any other person using the hoist.
Hoist Concrete Thickness Drawing
Hoist Concrete Thickness Drawing