An essential supply on any gunite project, gunite wire is used to make a guide line within the gunite concrete project. This guideline created by the gunite wire shows the gunite nozzlemen and gunite finishers the boundary line for the components of the project, such as the thickness of a wall in a gunite pool or the max height of another concrete surface in the project. As the gunite nozzleman is shooting material onto the construction surface, he knows that when the material builds up to that line, he has satisfied the amount of material needed for that section of the concete design. Gunite wire is known by several names. Historically, gunite crews would repurpose piano wire – the same wire used for the strings in a piano – using it as a concrete construction guideline. Many gunite and shotcrete contractors still refer to the product as piano wire today. Other names for gunite wire include shotcrete wire, shooting wire or ground wire, especially when marking lower elevations, such as flatwork and floors. Gunite wire is made of a spun steel and is produced in a few different diameters, which refers to the thickness or gauge of the gunite wire. A true shotcrete wire is normally a slightly thicker gauge than the wire used as gunite wire. This variation is due to the need for a slightly more sturdy wire to withstand the heavy wet shotcrete material. In either case, the gunite or shotcrete contractor has a choice of the packaging for their shooting wire, which is typically offered as either a loose bundle, a spool or within a box.