Manhole infiltration remains one of the most common problems faced by UK drainage contractors. Ageing brickwork chambers, poorly sealed connections and high groundwater levels can all contribute to excessive ingress, increasing treatment costs and placing unnecessary strain on downstream assets. In many cases, full replacement or excavation simply isn’t viable, particularly on live sites where access, traffic management or time constraints are a factor.
For these scenarios, systems like SealGuard II are increasingly used as a practical rehabilitation tool rather than a standalone repair. The product is typically selected where the manhole structure is fundamentally sound, but compromised by water ingress or voiding behind the chamber wall.
On site, contractors frequently encounter active groundwater entering through pipe-to-manhole connections, ring joints or degraded brickwork. In areas with high water tables, infiltration can be constant and pressurised, making traditional internal patch repairs ineffective. SealGuard II is applied by injecting the sealant through the manhole wall, allowing it to migrate into cracks and voids outside the structure. As it reacts with water, it expands and gels, forming a ridgid, watertight barrier that seals the leak path from the outside in.
A recent example saw one UK based Drainage Contactor dealing with severe infiltration at a defective manhole connection. Groundwater was gushing into the chamber, forcing the downstream pump station to work overtime. The team used SealGuard II to inject the void surrounding the manhole wall. Ten tubes were required to stop the flow, after which the connection could be sealed internally, completely eliminating the infiltration. UK drainage sites rarely offer ideal conditions. Contractors are often working in confined spaces, with live flows and limited control over groundwater. SealGuard II is particularly suited to these environments, as it can be installed from inside the manhole - as a fast-reacting, hydrophobic polyurethane grout that expands in seconds in the presence of water, reducing the need for dewatering or excavation.
Effective use does rely on proper training and experience. Understanding how water is tracking around the structure, selecting correct injection points and controlling pressure are essential to achieving a durable repair. When used correctly, the system is often part of a wider rehabilitation approach, stabilising the manhole and stopping infiltration so that longer-term internal repairs or coatings can be applied.
For drainage contractors, SealGuard II has become a practical solution for tackling some of the most disruptive manhole defects on UK networks - quietly reducing infiltration, extending life and keeping systems running as they should.
For more information on SealGuard products please contact S1E Limited: 01226 397015 or contact@s1e.co.uk
