The Overlooked Corrosion Solution That Could Help Concrete Pools Last Longer
August 11, 2026
Concrete, shotcrete, or gunite pools can be fun and even beautiful additions to home landscapes and play an integral role in marine exhibits for millions of tourists who come to watch killer whales, dolphins, or polar bears. However, they are inherently costly and vulnerable to corrosion, with many pools that cost $100,000 or more requiring rehab in 20 years or less. Well established in the construction world yet relatively underutilized in the pool industry, Migrating Corrosion Inhibitor™ (MCI®) technology offers a best-kept secret that pool owners, contractors, and shotcrete suppliers can take advantage of to get the most out of their investments or strengthen their warranties.
What Causes Corrosion in Concrete, Shotcrete, and Gunite Pools?
After five-plus years as a superintendent on swimming pool construction projects in Texas, Cortec® MCI® Regional Account Manager Sean Hightower remarked, “We used to have this funny saying that half of all new swimming pools leak, because it's true. Despite pressure-testing at various stages, leaks still occur more often than you realize – especially in expansive soils.” Whether a crack is allowing pool water to seep through the concrete wall and floors or a pipe is leaking behind the pool beam, the water is often absorbed by shotcrete, creating a corrosive environment for embedded reinforcing metal. On the deck side, constant splashing can cause seepage into poolside concrete. To make matters worse, application errors such as shallow rebar cover can accelerate corrosion onset from exposure to high-chloride moisture in and around chlorine-treated or saltwater pools.
How Can Migrating Corrosion Inhibitors Protect Concrete Pools?
MCI® is a versatile, workable way to slow down the corrosion process at any stage of a pool’s life, before or after cracks have formed. Once in contact with metal reinforcement, the chemistry—applied as an admixture, surface applied corrosion inhibitor (SACI), or injectable gel—forms a protective molecular layer that inhibits corrosion reactions in the presence of corrosives, delaying time to corrosion onset and reducing corrosion rates once started. Applications will look different at various stages of a pool’s life.
New Pool Construction: Adding MCI® to Shotcrete, Gunite, or Ready-Mix
General contractors or shotcrete/gunite/ready-mix suppliers can add MCI® admixtures to their mix to enhance corrosion resistance. Liquid admixtures are typically used at the batching plant while powder variations are often preferred for onsite mixing. Normal-set MCI® admixtures (e,g., MCI®-2005 NS, MCI®-2006 NS) make it possible to add the chemistry to shotcrete or gunite without disrupting the set time contractors need to form steps, benches, and other pool features. Extra MCI® Grenades (water-soluble pouches containing MCI® powder) are helpful to keep on the truck in case the volume of shotcrete needed changes from 60 to 70 cubic yards (46-53 m³) at the last minute.
Pool Maintenance: Reducing Water Intrusion and Rebar Corrosion
Hightower raised the following concern about pool upkeep: “What happens at a pool party? Well, everybody's jumping in, splashing water out. Water has to go somewhere. It's going into the concrete more often than not.” Routine application of a silane penetrating water repellant containing MCI® (e.g., MCI®-2018) offers dual protection by reducing water absorption and actively fighting corrosion with Migrating Corrosion Inhibitors if water does creep in to concrete pool decks.
Concrete Pool Repair: Using MCI® Gel and Repair Mortars
Once cracks occur, it is even easier for pool water to find its way to embedded reinforcement. In addition to sealing or patching these cracks, pool owners and contractors can inject MCI® gel (e.g., MCI®-2020 Gel) deep into the pool walls to make it easier for Migrating Corrosion Inhibitors to reach and protect the embedded reinforcing metal. In addition, repair mortars can be enhanced with MCI® Grenades or a similar MCI® admixture.
How to Extend Concrete Pool Service Life with Corrosion Protection
Pools remain popular despite high price tags and service life challenges. What many don’t realize is that Migrating Corrosion Inhibitors offer a promising remedy at a fraction of the total cost of the pool. Whether you are maintaining a pool or just getting ready to build one, be sure to consider the advantages of adding MCI® to delay corrosion and promote a longer pool service life. Contact Cortec® MCI® to learn more: https://www.cortecmci.com/.
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