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When planning a new gunite or shotcrete pool (or remodeling an older one), choosing the right material for the interior finish is among the best moves you can make.
Your pool’s interior finish—usually referred to as plaster—is what waterproofs its more porous gunite shell. This coating provides the surface that swimmers will feel beneath their feet or brush up against, and it contributes to the overall aesthetic appearance of the “liquid investment” in your backyard.
For decades, pool builders relied exclusively on marcite—white cement mixed with crushed marble dust that is applied by a trowel to a gunite pool interior to create a smooth finish.
This white plaster, which can be dyed in colors like blue or grey, is a proven material for pool construction. It is found in tens of thousands of pools across the country, and its initial price tag is reasonable. However, marcite has its share of shortcomings, including issues that create some long-term maintenance costs and requirements.
Better alternatives are available. One is colored quartz aggregate. This attractive, increasingly popular option has been used in pools around the country since the Nineties. While this upgrade may cost about 20% – 50% more than plain marcite, the value it delivers makes this upfront increase well worth it!
An innovation originally pioneered by industrial giant, the 3M Company, the material is created by using ceramics to permanently bond colored pigments onto the surface of specially produced granules of natural quartz.
During the production process, each manufacturer employs proprietary techniques to enhance their product’s hardness, uniformity, bonding, color, and resistance to penetration by water.
This winning combination of mineral and ceramic has much to offer. Quartz is one of the world’s hardest minerals. Unlike marble, which can dissolve from ongoing exposure to pool chemicals, quartz is completely insoluble.
As for ceramic coating, it has long been a leading method of preserving colored surfaces—and has been for centuries even before modern production techniques.
Once the quartz aggregate is created, it is mixed with plain marcite to create the plaster material for a pool. The colored blend is applied to the concrete structure in the same manner as a traditional plaster. However, the benefits are anything BUT the same.