Case Study: 150mm Cast Iron Soil Pipe Repair Leaking in Hospital Roof Space

Case Study Data

---

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

Products Used

---

CrackSeal Pipe Sealant
Sealant extruded directly into cracks in cast iron pipework, where it hardens almost instantly to seal the leak

SylWrap HD Pipe Repair Bandage
Composite repair wrap with water activated resin sets rock hard to reinforce pipework with an impact resistant 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

---

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.