Relining expertise at IWJS

The Task
What to do when you are faced with having to reline a 38m section of 750mm storm drain in a very demanding environment?

The site conditions meant that access to one end of the drain was on rough ground that suited 4×4 vehicles, the other end in tight residential roads a further 30 m on from the end of the relining section. In between, the drain running under houses and other structures.

When a major Water Utility company was faced with this particular set of problems, DSS Environmental Ltd demonstrated they had the capabilities and won the contract to undertake the works.

What we did

The three day project started by digging down to reveal the storm drain, cut through the top to gain access and build a tower to take the relining equipment.

Following a CCTV survey to finely assess and measure the problem section, a combination jet/vac unit was used to clean the drain followed by remote guided cutting equipment to remove tree roots.

A further CCTV survey confirmed the section was clean, clear and ready to take the liner.

The 2 ½ tonne pre-wetted (resin impregnated) liner that arrived in refrigerated transport on day two was winched through the access point and carefully positioned using the CCTV crawler as the underground eyes.

The next part of the process involved inserting a calibration liner inside the resin liner and using water to fill the ‘cali’ to press the resin liner to the sides of the drain ready for the curing process.

Using 3m BTU of heating capacity, the water in the calibration liner was heated to 80oC and kept at temperature for 8 hours to ensure the resin liner was properly cured.

Day three saw the safe removal of the equipment, a final CCTV survey to ensure the liner was fully functional and the making good of the site.

Safety is always paramount on this type of operation and the weather was constantly monitored. ‘Packers’ were used to temporarily stop the water flow throughout the three days and a Flexline tanker was on site 24/7 to over pump any rainwater if the weather turned. After all, that is the purpose of storm drains.

 The outcome

With a written report (including a CCTV survey DVD) sent to the client confirming a successful operation, IWJS have again demonstrated their expertise in the sewer relining and sewer repair sector.