Case Study Overview

Site Hospital
Location United Kingdom
Repair Type Leak repair
Defect Two-metre horizontal crack in 150mm cast iron soil pipe

Repair Products

CrackSeal Sealant, SylWrap HD Pipe Repair Bandage,
SylWrap Drain & Waste Pipe Repair Kit

Case Study PDF

Case Study Details

The cast iron soil pipe was part of the wastewater system installed when the hospital building was constructed in the early 1960s. It was located in a confined roof space, surrounded by other pipework, ducting and electrical cables.

Water starting to drip from a roof above a ward alerted the hospital to a problem. The maintenance team accessed the loft space and discovered a significant horizontal crack approximately two-metres long in the cast iron pipe through which wastewater was leaking.

Leaking pipes in hospitals were a hot topic at the time of the repair. Freedom of information requests submitted to NHS trusts as part of a national newspaper investigation showed hospitals in England recorded 456 sewage leaks into wards, maternity units and A&E departments over the previous 12 months.

Only 55 trusts out of more than 100 in England responded to the requests, meaning the true scale of the problem was certain to be much worse. Hospital trusts were therefore under scrutiny for how they responded to and managed leaks.

For this reason, the hospital kept a SylWrap Drain & Waste Pipe Repair Kit on-site, containing everything needed to permanently seal all types of drain, waste and soil pipes throughout its estate.

The cracked cast iron soil pipe could therefore be repaired instantly by the maintenance team; preventing water damage to the hospital building, limiting disruption to patients and staff and avoiding the sorts of dangerous leaks reported by other NHS trusts.

Using a standard sealant gun, CrackSeal Cast Iron Pipe Sealant was extruded directly into the crack along its entire two-metre length until it was totally filled.

CrackSeal is a specialist high-performance moisture curing sealant specifically formulated for sealing cracks and longitudinal splits. It is effective on wet surfaces and where water is leaking through at minimal pressure.

For this particular application, CrackSeal offered a faster repair than wrapping over the entire crack with Wrap & Seal Pipe Burst Tape – the other sealing material in the Drain & Waste Kit capable of wet surface repair.

As CrackSeal was extruded, it hardened instantly inside the crack. It formed a skin within 10 minutes, after which the cast iron soil pipe was reinforced with SylWrap HD Pipe Repair Bandage.

Two SYL633HD SylWrap Bandages were used. The resin in the bandage was activated with water and SylWrap applied around an area of the pipe just over two metres; encompassing the crack and giving the repair additional coverage either side.

Once cured, SylWrap formed a rock-hard, impact resistant shell around the pipe. From discovering the leaking pipe to completion of the repair, the entire application was completed in 30 minutes.

Had a Drain & Waste Kit not been available to the hospital, the cast iron pipe would have continued to leak wastewater until a repair solution was found – a process could have taken days.

Products Used

CrackSeal Sealant
Sealant extruded directly into cracks in cast iron, where it hardens almost instantly

SylWrap HD Bandage
Water-activated wrap used to reinforce repairs by providing a rock-hard protective sleeve

Drain & Waste Pipe Repair Kit
Specialist kit repairs multiple cracks and splits in cast iron drain, waste and soil pipes

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