How Much Crushed Stone Under Concrete Slab?

A 4 inch thick concrete slab must be covered with 3 inches of gravel. The best gravel is gravel with a depth of 3 inches, but it is also ideal for a 4 slab floor. Most driveways require at least 6 inches of stone crushed or gravel.

How Much Crushed Stone Under Concrete Slab?

Having a concrete slab is an ideal way to make sure your outdoor structures stand the test of time. But did you know that installing the right amount of crushed stone under the concrete slab is just as important? The crushed stone acts as a buffer between the soil and the slab, preventing soil erosion underneath the slab. It also helps to create a uniform and even surface for your concrete slab to rest on.

So, how much crushed stone do you need for your concrete slab? The answer depends on your project’s specifics and the size of the slab. Generally, though, you’ll need to spread 2-4 inches of crushed stone for a slab up to 4 inches thick. If you’re creating a slab that’s thicker than 4 inches, you should increase the amount of crushed stone to 4-8 inches.

Before you can lay the crushed stone, you’ll need to prepare the area. Begin by clearing away any grass, vegetation, or debris that may be in the way. Once the area is clear, you can begin to spread the crushed stone.

If the area is relatively flat, you can spread the crushed stone by hand. But if the area is sloped or uneven, you’