Manhole Rehabilitation

Mainstay Composite Liner

Restore, waterproof, and protect sewer structures.

Sulfuric acid attacks concrete and brick mortar, weakening the structure and shortening service life. Coast Underground applies restoration and corrosion barrier liner systems that rebuild damaged surfaces and help prevent future attack.

Mainstay ML-72 mortar restores deteriorated concrete and brick surfaces. Mainstay 100% solids epoxy coatings add the corrosion barrier, and many structures can be restored, protected, and placed back into service within 24 hours.

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Proven performance since 1962. Restores, waterproofs, protects.

Before and After Restoration

Corroded structures can be rebuilt and protected with mortar and epoxy liner systems.

Corroded manhole before rehabilitation — Before Sulfuric acid attack compromises concrete and brick mortar.

Restored manhole after composite liner rehabilitation — After ML-72 mortar and epoxy coating restore and protect the structure.

Restoration and Corrosion Barrier Composite Liner

The composite liner approach is built for utility structures that need more than a surface coating. It rebuilds the substrate, seals against water intrusion, and adds a corrosion barrier for harsh wastewater environments.

Manhole rehabilitation
Potable water linings
Application equipment support

Application Process

Prepared surfaces, structural mortar, then epoxy protection.

Step 1

Substrate Preparation

Prepare deteriorated substrates by water blasting, pressure washing, abrasive blasting, acid etching, or power tool cleaning.

Step 2

ML-72 Mortar Application

Apply Mainstay ML-72 mortar using shotcrete equipment, a trowel, or the Mainstay Mortar Spinner.

Step 3

DS-5 Epoxy Application

Apply Mainstay DS-5 epoxy to the mortar while it is still soft enough to indent with a fingertip.

Field Applications

Composite liner restoration can be applied across a range of wastewater and containment structures.

Composite liner applied to a brick structure — Brick structure rehabilitation

Composite liner applied to a channel wall — Channel and containment walls

Spray application of corrosion barrier liner — Spray-applied corrosion barrier

ML-72 Horizontal Pipe Restoration

Stay ahead of pipe decay by restoring deteriorated surfaces before damage gets worse.

Horizontal pipe before ML-72 restoration — Before restoration

Horizontal pipe after ML-72 restoration — After restoration

New Brochure Addition

Insta-Valve Plus installation support.

The updated brochure includes Insta-Valve Plus field imagery for underground valve insertion work. Coast Underground supports excavation, pipe exposure, gravel bedding, valve access assemblies, and trench installation around existing utility infrastructure.

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Excavated underground valve installation area — Excavation overview

Insta-Valve Plus installation in trench — Trench installation

Insta-Valve Plus features diagram — Features diagram

Product System

Coast Underground uses Madewell Mainstay rehabilitation materials for structural restoration and corrosion protection.