Three sewer sealant types, which are used to form a seal in joints and defects, were evaluated in this project. The sealants are used to stop sewer leakage, both infiltration and exfiltration, and in some cases to provide structural repair. The sealant types evaluated use the following materials:
- Polyurethane gels
- Two part epoxy resin
- Chemical stabilisers.
Four Water Utilities, WRc and four contractors were involved in the research to examine the performance of the three sealant types and to produce a specification for sewer sealing techniques. The research included analysis of:
- Long-term performance/durability e.g. ageing effects and effects of sewage on the sealant including any biodegradation
- Any potential environmental hazards from the material before and after cure.
- Lack of performance with existing products was identified
- A generic sewer sealing specification was produced which can be used as a standard document and referenced in sewerage rehabilitation contracts to ensure effective procurement and implementation.