A leaking welded joint between a steel pipe and iron pipe undergoes repair and encapsulation at a church in the UK

Church Central Heating System Steel & Iron
Welded Pipe Joint Repair & Encapsulation

A central heating system in a UK church was leaking at the point where a 100mm iron pipe stepped down to a 50mm steel pipe via a welded plate, requiring a complex repair and encapsulation to seal multiple leak areas across both pipes and at the joint.

Case Study Overview

Site Church
Location UK
Pipe Type Welded joint between 100mm cast iron and 50mm steel
Repair Type Leak repair and encapsulation
Products Sylmasta AB Original Epoxy Putty, Wrap & Seal Pipe Burst Tape, SylWrap HD Pipe Repair Bandage

Pipe Defect

During renovations carried out to the church central heating system several years previously, a 100mm cast iron pipe had been stepped down to a 50mm steel pipe via a 6mm thick steel plate.

Since the work, the system had become badly corroded and was now leaking from the welded joints and numerous points in both pipes surrounding the plate.

The church had repaired a similar problem to another section of the central heating system using a pipe repair clamp at considerable expense. The church were also keen to try and find a more cost-effective solution, a situation helped by the fact that a clamp could not be used this time due to the confined space around the joint.

Initially, the church called in welders to try and fix the problem. Not only did welding unfortunately fail, but it also left an even more uneven pipe surface needing to be sealed when Sylmasta were approached about the application.

Diagram of the joint requiring repair

SylWrap Solution

The biggest leak was on the 100mm cast iron pipe where it met the steel plate. This section was suffering from extremely heavy corrosion which had to be filed back before a repair could be attempted.

Once this had been done, Wrap & Seal Pipe Burst Tape was applied to the cast iron pipe. Wrap & Seal is made from self-amalgamating silicone and stretches by 300 percent, fusing to form a solid rubber band over leak areas for a pressure resistant repair.

The Tape was then overwrapped with a SylWrap HD Pipe Repair Bandage. SylWrap HD is a composite wrap with a water activated resin which sets rock hard in minutes to provide an impact resistant layer of protection.

Wrap & Seal and SylWrap HD are temperature resistant to 200ºC, enabling the repair to withstand conditions within the central heating system.

More challenging was the repair between the smaller 50mm steel pipe and the welded plate. Leaking in this area was caused by corrosion and uneven welding, whilst a threaded section of pipe close by was also suffering from a leak.

A softer material was needed to smear into the threaded section and penetrate the weld. 1kg of Sylmasta AB Original Epoxy Putty was delivered to the church for the repair of the steel pipe and the encapsulation of the entire joint where the 100mm pipe, the 40mm pipe and the steel plate had been welded together.

AB Original was smoothed over the welded joint, filling any imperfections to repair all leak areas. Its two-hour work time allowed large quantities of putty to be mixed and carefully applied without the danger of premature curing. It has excellent corrosion resistance, further protecting the pipe from future attack.

Corroded pipes and steel pipe before repair
Completed repair encapsulated with AB Original


When the church initially contacted Sylmasta, it had been with the intention of finding a temporary solution to keep the central heating system operational until a replacement could be afforded.

Instead, a permanent repair was made using Wrap & Seal, Sylmasta AB and SylWrap HD Pipe Repair Bandage at a fraction of the cost.

After the repair was successfully completed, the church told Sylmasta that they wished they had used this method for their earlier application rather than an expensive repair clamp.

Follow Up

The church who carried out the repair have since recommended that other churches in their area suffering from leaking pipes use SylWrap to repair and maintain their infrastructure.

Products Used

Wrap & Seal Pipe Burst Tape
Self-fusing silicone repair tape which seals live leaks with temperature resistance to 200ºC

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

Sylmasta AB Original
Super-strength epoxy putty for sealing cracks and encapsulating pipelines

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