Case Study: Repair of 1.05-Metre Long Crack in Cast Iron Downpipe at UK Hospital

Case Study Data

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Site
Hospital
Location
United Kingdom
Repair Type
Leak Repair
Defect
1.05-metre longitudinal crack in cast iron downpipe

Products Used

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CrackSeal Pipe Sealant
Sealant extruded directly into cracks in cast iron pipework, setting almost instantly for rapid sealing and repairs

SylWrap HD Pipe Repair Bandage
Composite repair wrap with water activated resin which sets rock hard to encompass pipes with an impact resistant outer sleeve

SylWrap Drain & Waste Pipe Repair Kit
Specialist Kit containing products for repairing low-pressure cast iron and plastic waste, sewer and drain pipes

Case Study PDF

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Case Study Details

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The hospital contained an internal 150mm diameter cast iron pipe system for taking away rainwater. The system was reaching the end of its lifespan, but budget restraints and the possibility of new facilities being built in the future meant replacing the ageing pipework was not considered viable.

Instead, the hospital was told to find cost-effective repair methods in the event of the system failing. Which is what happened when a 1.05-metre longitudinal crack developed in one section of pipework.

The leak was located in a constrained wall cavity where the pipe passed downwards through plasterboard on its way to the ground floor. The length of the crack meant it extended far enough on the pipe to also pass through the plasterboard.

When it rained, water escaped the pipe and saturated the plasterboard. This eventually led to rainwater dripping into a ward full of patients, at which point the hospital became aware of the problem. To ignore it would risk a significant leak developing into the ward, and damaging consequences for the ceiling and wall structure.

A specialist drainage engineer was called in. After accessing the wall cavity, removing some of the plasterboard and inspecting the crack, they decided to use the products in the SylWrap Drain & Waste Pipe Repair Kit to permanently seal the leak.

The Drain & Waste Pipe Repair Kit has been designed for repairing cracks and splits in low-pressure cast iron and plastic waste, soil and drain pipes. It comes in a robust red case which is easily kept on-site or on the van by facilities management teams, drain companies and others regularly required to repair such pipework.

Whenever a problem is identified, the user simply retrieves their Kit where everything needed to make multiple repairs quickly and easily is stored.

For this application, CrackSeal Pipe Sealant was used to fill the crack in the pipe. CrackSeal is a high-performance moisture curing sealant specially formulated to fill longitudinal cracks and splits in cast iron pipework.

Sufficient CrackSeal was extruded directly from its cartridge into the crack until it was totally filled. Although CrackSeal hardens almost instantly, it was left for 10 minutes to form a skin before the repair was reinforced with SylWrap HD Pipe Repair Bandage.

Two SYL616HD Bandages were wrapped along the entire length of the 1.05-metre crack, creating a two-layer repair. The water-activated resin set rock-hard in minutes, providing an impact resistant sleeve protecting both the CrackSeal and the rest of the downpipe.

Sylmasta normally recommend 10 layers of SylWrap HD Bandage be used for full reinforcement. Only two were needed for this application because the pipe took rainwater away at such low pressure.

The cast iron crack repair was completed in under 30 minutes with no disruption to patients or staff in the ward impacted by the leak. Numerous other repairs have now been using the Drain & Waste Pipe Repair Kit made to pipework across the hospital which has since failed.