Pool plaster is a critical component of any swimming pool. It serves both functional and aesthetic purposes, providing a smooth, waterproof surface that protects the pool’s underlying structure and enhances its visual appeal. Whether you’re constructing a new pool, renovating an old one, or maintaining your existing pool, understanding pool plaster is essential to ensure a long-lasting, beautiful swimming environment. This article will delve into the types of pool plaster, their benefits, the installation process, and tips for maintenance to help you make informed decisions.
Understanding Pool Plaster: What Is It?
Pool plaster is a specialized mortar used as the final coating on the interior surface of a swimming pool. It’s typically composed of a mixture of white cement, marble dust, and water, creating a dense, hard, and smooth surface. This coating is crucial as it provides a watertight seal, preventing water from seeping into the pool’s structure, which could lead to structural damage.
Beyond its protective function, pool plaster also plays a significant role in the pool’s appearance. The white or lightly tinted finish gives the water its classic, sparkling blue color, adding to the overall aesthetic appeal of the pool. While traditional white plaster remains popular, there are now numerous options available, including colored and textured finishes, allowing pool owners to customize their pool’s appearance.
Types of Pool Plaster
Traditional White Plaster
Traditional white plaster, also known as marcite, is the most common type of pool plaster. It has been used for decades due to its affordability and classic appearance. The bright white surface gives the water a light blue hue, which is a defining characteristic of many swimming pools.
While white plaster is cost-effective, it does have some downsides. It is prone to staining and can become rough over time due to the etching caused by chemical imbalances in the water. Additionally, it has a shorter lifespan compared to other types of plaster, typically lasting around 5 to 10 years before needing to be replaced or resurfaced.
Colored Plaster
Colored plaster is essentially the same as traditional white plaster, but with the addition of pigments to achieve a specific color. The most popular choices include shades of blue, gray, and black, each offering a unique aesthetic that can complement the surrounding environment or create a specific ambiance.
While colored plaster offers a more personalized look, it can be more prone to mottling, where variations in the pigment concentration cause uneven coloring. This is often seen as a drawback, but some pool owners appreciate the natural, variegated appearance that mottling can create.
Quartz Plaster
Quartz plaster is a step up from traditional plaster in terms of durability and aesthetic appeal. It is made by mixing crushed quartz with white cement, resulting in a much harder and more resilient surface. The quartz also adds a sparkle to the plaster, giving the pool a shimmering effect when the sun hits the water.
Quartz plaster is available in a variety of colors and is more resistant to staining and etching compared to traditional plaster. Its lifespan is also longer, typically lasting between 10 to 15 years. However, it is more expensive than standard plaster, making it a significant investment.
Pebble Finish
Pebble finishes are a popular alternative to traditional plaster, offering both durability and a natural, textured appearance. This type of plaster incorporates small, smooth pebbles into the cement mixture, creating a surface that mimics the look of a natural riverbed.
Pebble finishes are extremely durable, with a lifespan of 15 to 20 years or more. They are also highly resistant to staining, etching, and chemical damage. The texture of the pebbles provides a non-slip surface, making it safer for swimmers. However, the rougher texture may not be as comfortable to walk on for some people.
Polished Aggregate
Polished aggregate finishes, such as exposed quartz or granite, offer a high-end, luxurious look for swimming pools. The plaster is mixed with small pieces of quartz, granite, or glass beads, which are then polished to a smooth, glossy finish. This type of finish is not only visually stunning but also incredibly durable.
Polished aggregate finishes can last 20 years or more with proper maintenance. They are resistant to most types of damage and provide a unique, custom look that can be tailored to any aesthetic preference. However, this is one of the most expensive options for pool plaster, reflecting its premium status.
The Pool Plastering Process
Preparation
Before applying new plaster, the pool surface must be thoroughly prepared. This involves draining the pool and removing any existing plaster, debris, or dirt. The surface is then inspected for cracks or damage, which are repaired before the new plaster is applied. Any loose or rough areas are smoothed out to ensure a clean, even surface for the plaster to adhere to.
Mixing and Application
The plaster is mixed on-site, ensuring that it has the right consistency and composition. The application is done in two or more layers. The first layer, known as the scratch coat, is applied to create a strong bond with the pool’s surface. The final layer is applied over the scratch coat and is smoothed out to create the finished surface.
The plaster is troweled by hand, a process that requires skill and experience to achieve a flawless finish. The troweling process also determines the final texture of the plaster, whether it’s a smooth finish for traditional plaster or a textured finish for pebble or aggregate plaster.
Curing
Once the plaster is applied, it needs to cure properly to achieve maximum strength and durability. The curing process involves keeping the plaster moist for several days to prevent it from drying too quickly, which could cause cracking. During this time, the pool is slowly filled with water to help the plaster cure evenly.
Balancing the Water
After the pool is filled, it’s crucial to balance the water chemistry. Improper chemical levels can damage the new plaster or cause discoloration. The water should be tested and adjusted regularly, especially in the first few weeks after plastering.
Maintaining Pool Plaster
Regular Cleaning
Keeping your pool clean is essential for maintaining the plaster surface. Debris like leaves, dirt, and insects should be removed regularly using a skimmer. Algae growth should be prevented through proper chemical maintenance and regular brushing of the pool walls and floor.
Water Chemistry
Maintaining balanced water chemistry is one of the most critical aspects of preserving pool plaster. Imbalances in pH, alkalinity, and calcium hardness can cause the plaster to etch, stain, or become discolored. Regularly test the water and adjust the chemical levels as needed to prevent damage.
Addressing Stains
Stains can develop on pool plaster due to metals in the water, organic debris, or algae. Treat stains promptly using appropriate cleaning agents or stain removers to prevent permanent discoloration. For more severe stains, it may be necessary to acid wash the plaster, although this should be done sparingly, as it can wear down the plaster over time.
Resurfacing
Even with the best maintenance practices, pool plaster will eventually wear out and require resurfacing. The frequency of resurfacing depends on the type of plaster and the care it receives. Traditional plaster may need resurfacing every 5 to 10 years, while quartz or pebble finishes can last 15 to 20 years or more. Resurfacing involves applying a new layer of plaster over the old surface, restoring the pool’s appearance and functionality.
Conclusion
Pool plaster is a vital element of your swimming pool, providing both protection and beauty. With various types of plaster available, ranging from traditional white to luxurious polished aggregates, there is an option to suit every pool owner’s taste and budget. Understanding the plastering process and maintaining your pool correctly will ensure that your pool remains a stunning and enjoyable space for years to come. By investing in high-quality plaster and proper care, you can extend the life of your pool and keep it looking its best.
