In most residential garage floor applications, rebar (reinforcing steel bar) is not typically required. Garage floors are usually constructed using concrete, and while rebar can be used to reinforce concrete in some specific cases, it's not a standard practice for typical garage floors.
The primary purpose of rebar is to provide additional strength and prevent cracking in concrete slabs, particularly in situations where the concrete will experience heavy loads, significant stresses, or potential movement. For most residential garage floors, the concrete thickness and the typical loads they bear do not necessitate the use of rebar.
Instead of rebar, garage floors are typically constructed with a compacted gravel base for proper support and to prevent settling. Steel reinforcement may be added in the form of welded wire mesh or fiber-reinforced concrete (FRC), depending on local building codes and the specific requirements of the project.
However, it's worth noting that construction practices can vary by region and local building codes, so it's essential to check with your local building authority or consult with a structural engineer or contractor familiar with your area's regulations and construction practices. They can advise you on the appropriate specifications for your garage floor based on local building requirements and the specific conditions of your project.