General
Concrete Cutting and Drilling is done with diamond tipped drill bits and blades. It is the least destructive of all methods for removing concrete or forming penetrations in concrete structures. There is minimal structural damage to the remaining concrete. Diamond tipped drills and blades will cut reinforcing steel in concrete.
The operation is quick, quiet, and environmentally friendly. Health and safety risks are readily identifiable and therefore can either be eliminated or minimised. Care must be taken by owners and contractors on building renovations that the correct professional advice is received by registered engineers prior to structural modifications being undertaken
A variety of different methods are used for producing fast, clean, dust free and accurate cuts in reinforced concrete and other building materials. These include concrete sawing in walls and soffits, wire sawing and ring sawing.
NZ Concrete Contractors Members are responsible for producing quality work, adherence to regulations and a professional approach. Wherever possible choose a NZ Concrete Contractor Member for your job. See our Find Members tab for a list of NZ Concrete Contractors in your area.
Handheld Sawing
Handsaws are used in many applications to saw-cut floors, concrete precast walls, concrete pipes and concrete beams. They are probably the most commonly used concrete cutting tool in New Zealand. It is also the tool with the biggest potential to cause harm to an untrained operator. Hand saws in combination with a hand held “ring” saw can cut to a depth of 275mm. Most hand saws are 2-stroke petrol powered. For indoor use, to eliminate carbon monoxide fumes, there is a range of different types of hand held saws such as hydraulic, single phase electric, and hi-frequency. These are used for smaller space applications where a floorsaw cannot operate.
Track Mounted Wall Sawing
As the name suggests, this machine is primarily used to cut concrete and remove walls, mostly to form large openings in the wall for either doorways or air-conditioning ducts. A track mounted wall saw can cut to a depth of 800mm. These machines cut very accurately, typically to within 2mm or 3mm. The saws are remotely controlled so operators are well clear of any potential danger areas.
Wire Sawing
A continuous loop of diamond wire is “wrapped” around the concrete object that is being cut. This concrete cutting technique is very versatile. Cuts up to 20 metres long by 5 metres high have been made and reinforcing steel can be cut. A wire cut is not as accurate as other cutting and drilling techniques. Like a track mounted wall saw, a wire saw is remotely controlled. These saws are very quiet and therefore they are now being specified in noise critical areas such as hospitals and hotels.
Floor Sawing
Also called road sawing, ground sawing or flat sawing.
All professional concrete cutting companies use walk-behind machines. They range from 15 to 84 horse power and come in a range of petrol and diesel saws, depending on the manufacturer. There are 3 phase electric powered saws available for inside work to eliminate carbon monoxide fumes. The horse power of the machine determines the depth the machine can cut. A high horse power floor saw can cut to a depth of 600mm.
Typical uses for a floor saw are:
- To cut expansion joints in new concrete to help stop the concrete cracking over time;
- To cut thick concrete for removal;
- To sawcut asphalt to gain access to sub- base on roads.
Core Drilling
Concrete core drilling is used to form penetrations in concrete precast panels, block walls, beams or concrete floors to allow plumbing service pipes, electrical conduits and air conditioning units to pass through. Hole sizes range from about 12mm in diameter up to 1200mm in diameter.
Specialised deep core drilling can form a hole in excess of 30 metres deep. This type of drilling is typically used to form a precise round hole in concrete or masonry for the insertion of services or reinforcing. Often during seismic upgrades deep core holes are required inside the walls of buildings so that post tensioned rods can be grouted into the wall. A drill is used to remove a cylinder of material, called a core. Usually diamond core drills are used in order to best cut through the concrete and additional material. This technique of concrete cutting is often used for:
- Walls, floor slabs, and ceilings for electrical and communication services, cabling, plumbing, or HVAC
- Slab and roadway holes for dowelling drilling, rebar tie-ins, or drainage
- Recessed lighting and fixtures
- Sample and analysis of material
Bursting/Splitting/Crushing
A concrete burster or splitter uses hydraulic force to “split” a piece of concrete. This is used mainly to reduce a large section of concrete in size so that it can be removed more easily. These machines are used because they are more economical than cutting techniques available. A crusher has jaws that can crush concrete up to 300mm thick into small pieces. All these machines are quiet so, like a wire saw, they are ideal for noise critical areas.
Commercial Concrete Cutting
Our concrete cutters have a wealth of industry knowledge and highly trained workforces with specialised machinery ensuring they can offer their customers premier concrete cutting services. Cutting, sawing and drilling can all be performed on a variety of projects in construction or demolition with minimal noise and disruption.
Commercial concrete cutting is required when you need to prepare sections for removal or create concrete shaping on a project. Our commercial cutting members have years of experience in delivering a quality service using the latest technology and keeping health and safety at the core of their operations.
Residential Concrete Cutting
The prospect of cutting concrete can be daunting, but it doesn’t have to be. Using one of our skilled Concrete Cutting members means you get a quality job from a pre-approved cutter to work at your home. They have low noise, low emission tools they can use and will clean up after your job. Generally, a diamond blade will be used to get a smooth clean finish.
Your concrete cutter will be able to talk you through the process, explain the outcome and keep the process simple for you.