SewperCoat® celebrates 35 years as the leading solution against H2S corrosion in wastewater assets

For wastewater assets, biogenic hydrogen sulfide (H2S) corrosion is a problem that can’t be avoided. When concrete structures deteriorate, operators must act quickly to ensure the safety, reliability and longevity of their systems.

That’s why, for more than three decades, asset owners and engineers have turned to SewperCoat®, Imerys’ high-performance rehabilitation mortar designed specifically for aggressive wastewater environments.

As the original 100% calcium aluminate mortar on the market, SewperCoat® offers a monolithic fully mineral, highly resistant solution where ordinary Portland cement (OPC) and polymer-based materials often fall short. Its unique composition allows it to maintain a stable surface pH, disrupting the biological processes that cause biogenic corrosion and enabling decades of protection. Morever, SewperCoat® fast hardening behavior permits return to service within hours, even allowing to avoid heavy bypass costs in the most demanding conditions. 

Calcium aluminium cement delivers exceptional resilience

Calcium aluminate cement (CAC) was invented in 1908; by the 1930s, engineers had observed its exceptional behavior in sewer environments compared to OPC. Where surrounding concrete deteriorated under biogenic attack, CAC mortars remained intact. One striking example: a 25mm CAC lining installed in a precast concrete pipeline in 1959 was still providing active protection when the pipeline was taken out of service 58 years later.

In 1991, Imerys SewperCoat® was released, marketed as a dedicated rehabilitation mortar for wastewater structures. SewperCoat® gave wastewater network and assets owners a completely mineral solution, specifically engineered to resist biogenic H2S corrosion and resulting deterioration.

Increased durability for sustainable construction

By extending the service life of existing structures and reducing the need for repeated repairs, SewperCoat® helps wastewater operators manage networks more sustainably. Fewer interventions mean lower costs: lower material consumption, reduced energy use, shorter jobsite duration and a smaller carbon footprint over the life of an asset.

SewperCoat® has also earned Imerys’ Pioneer classification within its SustainAgility™ Solutions lifecycle assessment framework, highlighting how this product contributes to a more durable and sustainable construction industry.

A proven global solution for wastewater rehabilitation and long-term asset protection

From North America to Europe, Asia-Pacific and beyond, SewperCoat® has become a trusted solution by leading Asset Owners for wastewater rehabilitation. It sits at the core of the broader Sewper® range – including Sewper® Liner and the latest additions Sewper® Cast and Sewper® Backfill – offering asset owners a complete suite of solutions for both new construction and repair.

As it marks 35 years in service in 2026, SewperCoat® continues to set the standard for long-term protection in one of the most demanding infrastructure environments – helping operators safeguard their networks for decades to come.

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