1 ½ to 2 inchesClick to see full answer. Accordingly, what is the thinnest concrete countertop?Glass Fiber Reinforced Concrete can go as thin as 3/4″ for the same kitchen countertop slabs that would need to be 1.5″ thick for precast. what is the best concrete to use for countertops? QUIKRETE® Countertop Mix (No. 1106-80) is a specially formulated flowable high-strength concrete mix for pre-cast and cast-in-place concrete countertop applications. Super-plasticizer additive provides a flowable mix at low water/cement ratio. High-flow formula minimizes the need for mechanical vibration. In respect to this, can you use regular concrete for countertops? However, if you are dead set on using regular cement for a concrete countertop you’ll have to buy non-crack and non-shrink additives. You can’t use regular quikrete without additives for a concrete countertop. You can probably find a concrete countertop mix at your local Lowes.What do concrete countertops weigh?Concrete Countertop Weight. The weight of a concrete countertop has a lot of bearing on how it is built and how it will be installed. A standard 1.5” thick concrete countertop has an approximate weight of 18.75 pounds per square foot. In comparison, granite is approximately 18 pounds per square foot.