How Thick Does Concrete Need to Be for a 2 Post Lift?

It sounds like a simple question with a one-number answer. It isn't — and getting it wrong is how a two-post lift ends up leaning, cracking the floor, or dropping a car. A two-post lift channels the entire weight of your vehicle down two narrow columns and into a handful of anchor bolts. Those bolts only hold if the concrete underneath is thick enough, strong enough, and cured enough to grip them. This guide gives you the exact minimums, the numbers professionals actually use, and a five-minute test to check the slab you already have.

How thick does concrete need to be for a 2 post lift?

For a standard two-post lift, the concrete needs to be at least 4 inches thick, made of 3,000 PSI (or stronger) steel-reinforced concrete, and cured for a minimum of 28 days. That 4-inch figure is the accepted floor across the industry: BendPak lists 4¼ inches as the minimum for its two-post lifts on a pre-existing floor, and specialist retailers echo the same 4-inch, 3,000-PSI baseline.

The catch is that 'minimum' and 'recommended' are two different numbers. Four inches will carry a light-duty lift on a good slab, but it leaves almost no margin for error. As SVI International puts it, 'a minimum of four inches of reinforced concrete is the standard, however, ideally, you should have at least six inches, and as much as twelve.' Six inches is the number most installers reach for, because it keeps the anchors well within solid concrete instead of near the bottom of a thin slab.