How Much Rebar for a Patio?

Types of Concrete Reinforcement

• There are three primary types of reinforcement you can use for your concrete patio. Reinforcing bars, commonly referred to as rebar, provide the greatest amount of strength for your concrete patio project, but they are also the most expensive option. Fiber mesh is a strengthening additive that you can order to be mixed into your concrete when it is delivered. Fiber mesh will add strength to your patio and help to prevent cracks, but if a crack occurs fiber mesh will not prevent it from spreading. Wire mesh will help prevent cracks from spreading and is less expensive than rebar, but it comes in rolls and can be difficult to work with.

Size

• Rebar is sized to industry standards with different diameters that correspond to its application. No. 3 rebar, which measures 3/8 inch in diameter, is sufficient for residential concrete patios, according to the Renovations Headquarters website. The Boss Construction website notes that reinforcing your patio with rebar could be unnecessary if your concrete subgrade is stable.

Placement

• You should place the rebar in the center of your patio, rather than at the top or bottom. The rebar should not extend all the way to the edges. Lay your rebar sections parallel to each other, approximately 18 inches apart. Create a rebar grid by laying sections perpendicular to the first sections, resulting in 18-inch squares.

Secure and Elevate

• You should secure the rebar pieces together at each point of intersection with tie wire. A special tying tool helps you get a secure and stable connection. Once you have all the intersections connected, you will need to elevate the entire grid to a height equal to 50 percent of the thickness of your concrete. If you will be pouring a 4-inch-thick patio, you will need to elevate your rebar by 2 inches. You can use pieces of bricks or stone, or you can use inexpensive rebar supports that are manufactured for that purpose.