Wire Sawing

Wire sawing is what you use when the section is too thick, too awkward or too sensitive for a disc. A diamond-beaded wire is threaded through the structure, joined into a loop and run continuously under tension by a hydraulic drive unit, cutting in one direction rather than in passes. Because the wire has no radius, the section thickness is not what limits the cut. The practical limit is getting the piece out afterwards.

A floor or wall saw is limited by its blade, reaching a little under half the disc diameter once the guard and arbor are allowed for. The largest wall saws in common use take a 1,600mm blade and cut to around 730mm from one face, and cutting from both faces doubles that. Past what a disc can reach, or where the cut runs in two planes, or where there is no room to swing a machine, the disc stops being an option. Mass concrete, bridge piers and abutments, deep foundations, thick quay walls and heavily reinforced transfer structures are all wire saw work.

It is also the answer where vibration is the constraint rather than the thickness. A wire saw is a continuous, low-vibration cut, which matters next to sensitive equipment, on a live hospital estate, or where a structure is already distressed and percussive breaking would make it worse.

Where the cut is an opening inside a structure, the wire has to get through it, so the job begins with core drilling: a pair of holes cored at the corners of the intended cut for the wire to pass through. A free-standing element such as a pier or a column is simply wrapped instead. That means the coring has to be accurate, because the wire will follow the line those two holes define.

From there it is about tension, water and control of the section. Water is not optional: the Drilling and Sawing Association Code states that it must always be used and fed to the wire throughout the cut. The pulleys and the wire run unguarded, so the working area is isolated rather than fenced at the machine. The drive unit maintains tension as the loop shortens; water cools the beads and carries away the cuttings; and the piece being removed has to be supported or lifted before the cut completes, because a released block of mass concrete is a serious load. Sequencing the lift is usually the part that decides the programme.

Cuts are clean, square and need no making good. There is no percussion, so no impact damage to what is left behind. Slurry volumes are higher than disc sawing and have to be contained and removed rather than run to drain, particularly on port and airfield sites where drainage runoff is an environmental compliance issue.

We are based at Little Westerhill Farm near Maidstone in Kent. Kent, London, Sussex, Essex and the wider South East are covered from our own yard, and longer programmes are mobilised UK wide. Wire sawing sits within our concrete cutting service, alongside wall sawing and floor sawing.

For slabs within reach of a disc, see full depth sawing.