Pouring your own garage floor is an attainable goal with enough time and manpower. To ensure the strength and durability of your floor, you need to know how thick to pour your concrete.
The standard concrete garage floor is 15 cm (6 inches) thick and, with use of proper control joints, should be thick enough to withstand normal use.
Type of use
How thick you pour your concrete floor can be determined by how the floor is going to be used. This is largely based on the types and the number of vehicles you plan to park on it.
For one to two light cars or trucks, you can generally get away with pouring less concrete. For small cars the concrete should be at least 10 cm (4 inches) thick.
If you intend to use the area for average-sized vehicles and/or medium to heavy trucks, the concrete needs to be 15 cm (6 inches) thick.
If your garage floor is going to see constant traffic from heavy vehicles, it is recommended that you pour your floor at least 15 to 20 cm (6 to 8 inches) thick. Your floor must also be treated and sealed properly so that heavy loads like large trucks do not cause the concrete to crack.