Is it better to put gravel under concrete?

You do need gravel under a concrete slab, footing, or patio. Gravel provides a solid foundation for your concrete as it can be compacted. It also improves drainage, preventing water from pooling beneath the concrete.

How many inches of gravel do you need for a concrete slab?

Excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete.

Can you use gravel as a sub base for patio?

Gravel patio benefits Easy to lay – gravel is an easy material to lay due to its size compared with alternative patio surfaces such as decking or concrete paving. Drainage – gravel surfaces are porous and provide natural drainage, leaving your gravel patio puddle free.

What kind of gravel do you put under concrete?

Gravel for Concrete Depending on what the driveway will be used for, the base may need to be 4 to 12 inches. Ideally, 6 inches of crushed stone or gravel should be used for most driveways. Proper application requires that the driveway hole be dug out, and the soil has to be prepared.

What is the best gravel to put under concrete?

Most people build a driveway or a patio so in that case, a good choice would be a mix of coarse and fine aggregate which will create a compactable base. Overall, a mix of crushed stone and stone dust is the best base material for any concrete flatwork. It all comes down to the ground and soil you will be working with.

How thick should a patio sub-base be?

How deep should my sub-base be? Generally, a flexible sub-base of unbound material needs to be at least 100mm deep, as does a bound sub-base of CBM/HBM. For bitumen-bound material, then 50mm is a typical minimum thickness.

How deep should a patio sub-base be?

Dig a depth of around 150mm across the whole area, making sure the soil is evenly compacted. Then tip in the sub-base, raking it into a consistent depth of 100mm. Make sure it’s smooth, flat and firm.

What is the best way to compact gravel?

Starts here4:42How to Use a Plate Compactor – YouTubeYouTube

What size gravel is best for concrete?

Gravel for Concrete Ideally, 6 inches of crushed stone or gravel should be used for most driveways. Proper application requires that the driveway hole be dug out, and the soil has to be prepared.

How much gravel do you put under a 4 inch slab?

You will need 3 inches of gravel under a concrete slab that is 4 inches thick. More gravel is better, but 3 inches is the minimum amount of gravel you should have with a 4” slab. Use ¾” washed and screened gravel, then compact it to level.

How much does it cost to fill in a 2 inch slab?

Its about 3.75 cu yards of crete, or like $400 It will cost $100 for gravel to fill in 2″, but my crete is still only a little cheaper, and it will be a thinner slab. I could put gravel in, say 2″ and 3.5″ of concrete over that or just full 5.5″ of crete or I could do lot of gravel and a 2″ top coat over that with a bunch of steel and fibers,

How thick should a subbase be on a concrete slab?

The entire subbase and base system should be at least 4 inches thick—thicker if the engineer feels it is needed for proper support. The base course material, according to ACI 302, “Concrete Floor and Slab Construction,” should be “compactible, easy to trim, granular fill that will remain stable and support construction traffic.”

Can you use a plate compactor to compact gravel?

When compacting gravel designated for a foundation of a concrete slab, it is best to use a machine. A plate compactor or jumping jack will compact the gravel in a fraction of the time that it would use to use a hand tamper. If you have more than 5” of gravel, you’ll have to compact gravel more than once.