The repair of a leaking underground water main which had proven impossible to fix for 15 years before SylWrap came up with a solution
A carbon steel underground water remain had been leaking for 15 years before a SylWrap Live Leak Pipe Repair repaired the problem

Burst Water Main Repaired After 15 Years of Leaking

After 15 years in which no maintenance or water company had been able to find a solution to repair a burst underground 400mm carbon steel water main, a SylWrap live leak repair provided a permanent solution to a previously unfixable problem.

Case Study Overview

Site Underground water main
Location United Kingdom
Pipe Type 400mm carbon steel water main
Repair Type Live leak repair
Products Wrap & Seal Pipe Burst Tape, SylWrap HD Pipe Repair Bandage

Pipe Defect

The 400mm carbon steel water main was leaking from a large split across its diameter. The normal method of repair for such a section of pipework on a supply network would be a pipe repair clamp.

In this instance, the constrained space around the water main made using a clamp impossible. Only a single contractor could access the main at any one time.

To replace the water main would involve digging up the area surrounding the main. So important was the water main to the local network that shutting it off to carry out a replacement was considered unviable.

These complications were why the main had been allowed to leak for 15 years. The only possible solution was a flexible repair effective in a confined space which could be carried out whilst water pressure remained on.

An underground burst carbon steel water main on the UK water network which had not been repaired for 15 years
Burst water main with difficult access

SylWrap Solution

After the latest contractor hired to try and find a solution contacted Sylmasta about the possibility of a composite solution, a SylWrap live leak repair method was devised by Sylmasta’s technicians.

It was decided that the best way to attempt to seal the leak would be by double wrapping from the flange up the tapered pipe. Given the difficult nature of the repair and the space constraints involved, a number of Wrap & Seal Pipe Burst Tapes were delivered to the contractor along with SylWrap HD Pipe Repair Bandages.

Wrap & Seal is a self-fusing silicone tape which stretches by 300 percent, forming a solid rubber band which seals highly pressurised lie leaks. Multiple Wrap & Seals fuse to each other in the same way that a single tap does itself and can be used to build a repair capable of withstanding up to 30 bar pressure.

Double wrapping Wrap & Seal increased the pressure resistance of the repair and compensated for the lack of space around the burst water main, which may have prevented the tape being stretched to its full capacity.

After successful application and fusion of Wrap & Seal to seal the leak, the repair was overwrapped with multiple SYL416HD Repair Bandages.

Sylmasta would normally have advised the use of a SYL866HD Bandage but sized 200mm x 20m, there would have been no room to apply such a large wrap to the pipe. At 100mm x 5m, several SYL416HD Bandages were more manageable in the space constraints.

SylWrap HD is a composite repair wrap with a water-activated resin which sets rock hard in minutes. Applying SylWrap HD increased the strength of the repair, providing an impact-resistant layer of protection and a permanent solution.

Because the underground burst water main was part of the public supply network, any repair products used had to have WRAS approval, certifying them as safe to British standards for use with pipes carrying drinking water. Both Wrap & Seal and SylWrap HD carry the necessary accreditations.

Completed repair of the underground water main


Within an hour of the contractor undertaking the application, the SylWrap repair had successfully sealed the crack on the burst underground water main after 15 years after leakage.

Following the repair, the contractor expressed their satisfaction with the products and the technical advice offered by the Sylmasta team in finding a solution to a problem previously considered unfixable.

“The repair was a complete success, as we knew it would be. The information that Sylmasta provided greatly supported the project and more importantly, future projects.”

Follow Up

SylWrap repairing a burst underground water main which had been allowed to leak for 15 years highlights the advantages of composite pipe repair solutions over traditional clamps.

Several of the United Kingdom’s water companies and the national supplier in Malaysia responsible for Kuala Lumpur have since approved the SylWrap Pipe Repair Contractor Case for making rapid emergency live leak repairs to pipes on their networks as soon as problems are detected.

The Contractor Case contains enough pipe repair products to make up to six repairs. It is easily stored on the van, meaning that a contractor simply reaches for their Case and 30 minutes later the leaking pipe will have been permanently repaired. There is no need to leave pipework to leak for 15 years.

Products Used

Wrap & Seal Pipe Burst Tape
Self-fusing silicone pipe repair tape for sealing high pressure live leaks

SylWrap HD Bandage
Water-activated wrap sets rock hard to reinforce, protect and strengthen repairs

Universal Pipe Repair Kit
Wrap & Seal and SylWrap HD can be purchased together in a Universal Pipe Repair Kit

Pipe Repair Contractor Case
Easy-to-store case with everything needed to make up to six emergency pipe repairs

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