Clearing tarmac and concrete

Sewer and pipe renovation specialist CJ Kelly International recently assisted with a pipe cleaning project undertaken by drainage contractor Fastflow Drains. Tarmac and concrete deposits had to be removed from a pipeline serving a residence in Vicarage Gate, near Kensington.

The pipeline in question comprised a cast iron drain which runs directly under the property through solid ground and concrete, making traditional open-cut replacement of the pipeline, out of the question. Time for a trenchless solution, in other words. A build-up of tarmac and concrete materials in the drain, highlighted by a CCTV survey, were causing damp problems in the basement flat.

Fastflow used a Picote Super Midi machine for cutting out the tarmac and concrete from the cast iron drain. The Picote cutting heads were used with a Tiger bore drill head, a 100 mm diameter Tiger Drill chain, a 75 mm diameter Tiger twister concrete/liner removal tool, a leader cable, hub and grinding panels, and a Flexian 3,000 psi@16 gpm high pressure water jetting machine. The operation was monitored using an A&M Industrial CCTV Camera system.

The machine removed the tarmac and concrete in three passes through the pipeline. The contractor then ran the machine with the tiger drill chain and leader cable hub and grinding panels to clean up any remaining deposits. The drain was finally cleaned with a high pressure water jetting system before completing a final CCTV Survey.

However, the drain was found to be holding water after removal of the tarmac/concrete, and this was attributed to a back-fall on the drain. Fastflow recommended re-lining of the drain to the client.