The Mainstay Composite Liner was originally developed by United States Steel Corporation as a process for lining uncured reinforced concrete pipe (photo on the left). The USS Chemicals division performed the first commercial application of Mainstay in 1962. Several million square feet of Mainstay was applied by U.S. Steel crews over the following nine years. In 1971, U.S. Steel decided to divest its coatings interests, including Mainstay. Madewell Products Corporation was established soon thereafter to manufacture Mainstay products. Over the last 50 years, Mainstay brand products have been used to line concrete surfaces in sanitary sewer and industrial environments throughout the U.S. and abroad. Today, Madewell Products manufactures a variety of cementitious and epoxy products, including aquarium lining systems, moisture mitigation systems, and floor leveling materials. Madewell also manufactures specialized application equipment for use with these materials. All products and components are manufactured at Madewell's headquarters in Alpharetta, GA.

Mainstay Composite Liner

Madewell Products Corporation manufactures a variety of cementitious and epoxy products for restoration and protection of structures in the sanitary sewer, potable water, and industrial process markets. Some of these products are combined to form the Mainstay Composite Liner. The Mainstay Composite Liner is a two-component system consisting of a high strength restoration mortar, such as Mainstay ML-72 Microsilica Restoration Mortar, and an epoxy corrosion barrier coating, such as Mainstay DS-4 or 5 Epoxy Coating, that cures simultaneously to repair and protect concrete and brick structures. The mortar is first shot onto a new or deteriorated substrate, and an epoxy topcoat is then immediately applied while the mortar is still soft. The simultaneous combination of these materials creates a monolithic lining that cures into a strong, highly corrosion resistant, and continuous surface, free of pinholes, holidays, and voids. The mortar and topcoat are tightly bonded not only to the substrate but also to each other.

Advantages of the Mainstay Composite Liner

Sample of the Mainstay Composite Liner used in manholes and lift stationsThere is no wait time for the mortar to cure because the epoxy topcoat is applied while the mortar is still soft. Therefore, the system can be installed quickly, and deteriorated structures can be repaired and put back into service in a single day. This reduces labor costs and saves time. The need to mobilize twice is also eliminated for small structures such as manholes due to the concurrent application of the cement mortar and epoxy coating.
This system is also specifically designed for use in moisture laden environments. Surfaces in manholes and lift stations are often continuously damp, making it almost impossible to apply a protective coating alone. Cementitious products used in the Mainstay Composite Liner are properly applied when the surface of the concrete or brick substrate remains damp, eliminating the tedious task of drying the substrate prior to application.
One main component of the Mainstay Composite Liner is Mainstay ML-72 Sprayable Mircrosilica Mortar. It is a high-build restoration mortar that can be applied to vertical surfaces up to 5" thick, often restoring the surface to its original thickness. The cured mortar has a compressive strength of 10,000 PSI, resulting in a restored surface that is stronger than the original structure.
Mainstay DS-4 and DS-5 are 100% solids epoxy coatings. These highly corrosion resistant coatings contain no solvents and may be applied up to .125" (125 mils) in a single coat.

Cross-section of mortar and coating displays the strong bond between the two productsThe closeup photograph to the right shows a cross section of ML-72 mortar (gray–on the bottom) and DS-4 Epoxy Coal Tar (black–on the top). Note that the two products are both physically interlocked and chemically bonded.

Floor Leveling & Moisture Mitigation Overview

Madewell Products Corporation manufactures products for leveling and mitigating moisture in concrete slabs prior to the installation of finished flooring.
Floor Leveling

Pumping Mainstay self leveling underlayment onto substrateInstallers often find that subfloor surfaces are not sufficiently flat and level to install flooring materials. To correct this problem, a variety of cementitious underlayments may be used. More commonly, self leveling underlayments are employed because they are fast, economical, simple to use, and highly effective. Madewell manufactures Mainstay SLU-HC, a premium calcium aluminate self leveling underlayment that bonds tightly to both concrete and nonporous substrates to provide a smooth, hard, flat floor suitable for the installation of almost any flooring product.

Zoo & Aquarium Polymer Lining Systems Overview

Madewell Polymer Lining Systems can be used to waterproof, corrosion-proof, and restore concrete structures in aquariums, zoos, and fish hatcheries. These lining systems provide a safe living environment for fresh and salt-water fish and marine mammals.
Madewell Unreinforced Polymer Lining Systems: These systems perform well in subterranean structures or structures subject to high water tables and hydrostatic pressures. They restore rough, deteriorated concrete and provide an attractive, durable, nontoxic, and easy to clean surface.
Madewell Crack-Bridging Laminate Lining Systems: These systems are designed to resist cracks within the substrate up to 1/16" in width and prevent corrosion of reinforcing steel. They perform well in above-ground aquaria where there is occupied space around and/or beneath the aquarium structures and where the consequences of leaks may be catastrophic.
Mainstay ML-Flex Cementitious Waterproofing Membrane: This product is considered a low-cost alternative that may be used in "back of house" applications or beneath theming (e.g. artificial rockwork and coral) where appearance and cleanability are of secondary importance. It resists hydrostatic water pressure and produces excellent adhesion to properly prepared substrates.