Quick Answer: Do I Need Gravel Under Concrete?

Is wire mesh better than rebar?

Considering the support constraint, rebar is undoubtedly stronger than wire mesh.

Several constructors consider rebar for domestic jobs.

For thicker driveways and locations that involve greater traffic, rebar is always a good option to consider..

What size rebar do I need for a 4 inch slab?

Also to know is, what size rebar would be used on a 4 slab? For driveways and patios a #3 rebar which is 3/8 inch in diameter should be sufficient for the purpose. If you are constructing walls, piers or columns I recommend the use of #4 (1/2 inch) rebar. For building footings I would use a #5 (5/8 inch) rebar.

What is the best base for concrete?

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.” ACI 302 recommends material with 10 to 30% fines (passing the No. 100 sieve) with no clay, silt, or organic materials.

Is sand a good base for concrete?

Pour concrete over a solid, well-drained base of sand or gravel over clay and other poorly draining soils to provide even support.

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 pour concrete without gravel?

Long story short, yes you can pour concrete over dirt.

What kind of gravel do you put under concrete?

Backfill beneath concrete flat-work along foundation walls should be accomplished with a granular material that is uniform in size. Some fill materials, such as round stones like pea gravel, tend to be self compacting. “I recommend open-graded granular material be used,” says Tull.

Can you pour concrete on dirt?

No, Because concrete slabs “float” on the soil, soft ground or voids underneath may cause unsupported areas to crack under heavy weight like vehicles. Pack about 4 in. of sand or gravel over clay and other poorly draining soils to provide even support.

Do you need rebar for 4 inch slab?

No, you do not need rebar for a 4-inch slab of concrete on grade. A 4-inch-thick slab cast on the ground and in permanent contact with it will float and rebar is not required. Rebar is recommended on concrete measuring 5 – 6 inches thick.

How many bags of concrete do I need for a 10×20 slab?

For a 10 x 10 slab, you would need 77 60-pound bags or 60 80-pound bags. If we add an extra 10%, that’s an extra 8 60-pound bags or 6 80-pound bags.

Do you need wire mesh for 4 inch slab?

No, they do not. Larger projects or slabs may need steel reinforcement to provide support or extra strength. Wired mesh can also help resist cracking. However, not every piece of concrete necessarily requires that extra boost.

What size gravel is best for concrete?

In order to minimize cracking, it is ideal to use a mix design containing aggregates ranging from natural sand, to 1-1/4″ at an average of 18-22% of each size by weight. Explanation: 3/4″ is typical.