How Deep Should a Concrete Slab Be for a Carport?by Katherine Harder
At Least 4 Inches
In an article for Residential Construction Magazine, Pieter Vanderwerf, president of a consulting company to construction firms, states that the standard thickness for residential concrete pads is 4 inches. Remember to account for the end of your slab, which you should allow to taper into a wedge shape, creating a ramp for your vehicle.
Greater Thickness for Heavier Loads
If you own a recreational vehicle, garbage truck or other heavy vehicle, increase your carport's concrete pad thickness to 5 to 6 inches, a thickness that can better handle a heavy load without cracking.
Four inches deep is the industry standard for carport concrete pad thickness. Add an extra inch or two for carports that must support heavy loads.