Q.: I frequently hear warnings about leaving wire mesh too low in a concrete slab on ground. I'm told the mesh won't keep cracks closed tightly if it isn't high enough. Is there any problem if it's too high, say 1/2 inch to 1 inch from the surface?

A.: If wire mesh is too close to the surface it may corrode, especially in exterior applications where the concrete won't be continuously dry. Generally, the minimum cover for wire mesh should be 1 1/2 to 2 inches.