North Carolina General Contractors Practice Exam

How deep should welded wire fabric be placed within a concrete slab?

1. At the surface level

2. 1 inch from the top

3. 2 inches from the top

4. 3 inches from the top

The correct answer is: 2 inches from the top

Welded wire fabric, often referred to as reinforcing mesh, is typically placed within a concrete slab to enhance its tensile strength and prevent cracking. The optimal placement depth for the mesh is usually around 2 inches from the top of the slab. This position allows the fabric to effectively counteract tensile stresses that occur within the concrete due to various loads, ensuring that the mesh is well-embedded within the concrete where it can perform most effectively. Placing the welded wire fabric too close to the surface may expose it to potential corrosion or damage over time, while positioning it too deep would limit its effectiveness in reinforcing the top section of the slab where the tensile strains are greatest. Understanding how to correctly position the welded wire fabric is essential for constructing durable concrete structures, thus enhancing the overall longevity and performance of the slab.