Hydrodemolition – A gentler approach

Traditionally, concrete removal has been completed using pneumatic chipping hammers

Intergroup’s new hydrodemolition technique uses high- or ultra-high-pressure water blasting to remove concrete – ‘blasting away’ traditional demolition issues.

Read also: UHP Water Jetting and Abrasive Blasting & Industrial Coatings


  • Partial removal of aged/damaged concrete in preparation for repair
  • Cutting into new or existing structures to facilitate tie-ins
  • Scabbling for bonding new concrete to old
  • Isolated troubleshooting repairs to recently completed infrastructure
  • Expertise in wharves, bridges, buildings, tunnels and drainage networks


  • High-pressure water jetting (15,000-25,000psi) or ultra-high-pressure water jetting (25,000-55,000psi)
  • 180hp right up to 1,000hp
  • Hand-lancing capability up to six lances
  • Robotic tools for higher productivity, safety and efficiency, e.g. Conjet
  • A wide range of customised tools (lances and nozzles) selected to suit your needs


Cost-Effectiveness, Speed and Efficiency

  • A one-stop shop – combined with your other infrastructure/industrial services needs
  • Varying selection of machine types, power rating and water pressures allows a tailored service to suit your needs, budget and programme
  • Robotics and high-pressure water jetting for speed and efficiency
  • Less removal of sound concrete means less time and money spent replacing it


  • More accurate – less concrete is removed
  • No cracking or fissures to the adjacent sound concrete (as can occur when using hammers)
  • Doesn’t damage or bend reinforcing steel out of shape

Risk Reduction and Reputation

  • Full Kevlar wet-weather equipment and full-face air-fed helmets for safety
  • Robotic tools for safety
  • Operators trained in safe work at heights, tidal work and water jetting
  • Containment of waste for safety and environmental protection (using vacuum loading)
  • Environmental protection methodologies tailored to suit the environment


  • Manukau Harbour Crossing – hydro demolition for abutment removal to facilitate steel tie-ins.
  • Hydrodemolition bridge work for Fulton Hogan and Downer in Thames.
  • Victoria Park Tunnel – Intergroup’s hydro demolition experts were called in to adjust the drainage that had been constructed to ensure it could handle a 100-year flooding event.
  • Scabbling work using hydro demolition for Fletcher Construction on concrete structures in Christchurch and on Watercare’s wastewater networks.
  • Wharf repair jobs using hydro demolition including Queens Wharf in Fiji, wharves in Raglan and Birkenhead, Captain Cook Wharf, Queens Wharf and the Wynyard Quarter in Auckland, and Lyttelton Port.
“I would like to give praise to the team you had working at nights in the tunnel. First of all, the gear did what we were told it was capable of doing. Secondly to make the gear work you need the right team. Full credit to your team, as not one safety incident needed to be raised… a very smooth, productive operation. It was a pleasure to have their contribution to our site works.”

Garry Howard,
Senior Foreman,
Victoria Park Alliance


“We started using Intergroup in 2008. We’ve always had a good working relationship and would categorise them as friendly and flexible.
Hydrodemolition is much faster than jack-hammers, does a better job, prepares the rebar at the same time and is more economical. What we’d do in a day with 10 men is the same as one machine can do.”

Mark Kurtovich,
Special Projects Manager,