Swimming Pool Plastering is an age-old process that can be used to refinish your pool or add an entirely new surface to it. It is a relatively inexpensive way to update your pool and creates a smooth surface for swimmers that provides a comfortable and safe experience. Replastering also can enhance the aesthetic of your pool and increase its resale value.

Pool plaster, also known as whitecoat, lasts for 20 years under ideal conditions, but our world is not ideal and many pools require replastering before that time. Plaster surfaces are vulnerable to a number of different problems that can shorten the lifespan of your pool.

These include water chemistry, algae growth, organic stains, chemical and physical damage to the surface, poor construction, or simply age and wear. The most common problem is staining, which can be caused by a wide variety of things. Stains can be organic (such as leaves, twigs and branches), mineral deposits or due to excess Calcium Chloride. Mineral stains can be caused by hard water, high PH levels, or due to the presence of dissolved iron or manganese.

Acid washing is the common solution for stains that brushing and sequestering agents are not able to remove. The acid wash breaks down the surface of the old plaster, which exposes the bright white material beneath it and is able to get rid of the hard-to-remove stains.

Other types of stains can be caused by the natural environment around your pool, such as leaves or twigs that fall in the water and leave behind a green or brown coloration from the chlorophyll in them. Organic stains can also be caused by the breakdown of organic matter such as dead plants that can then decompose and form an earthy or dark hue on your pool plaster surface.

Keeping your pool water chemistry in balance is the key to keeping your plaster in good condition. A ph of between 7.2 and 7.6 is ideal, and your Total Alkalinity should be kept in the range of 120-150 ppm. Having your TA in this range will keep your pool water from stealing calcium from the plaster surfaces, which can cause scaling and filming. To raise TA, use a product such as Alkalinity Increaser. To lower TA, you can use a product such as pH Decreaser, aka Dry Acid.

Once you have the proper chemistry, your pool is ready to be replastered. The plasterers will drain the pool and begin the prep process, which includes draining the water, removing all existing tile and liner, etching the surface with an acid wash and scrapping off loose or hollow areas of the existing plaster. A specialized bonding material is then applied, usually a Bond Kote material which is a one-part resin, one-part bonding cement acrylic modified cement and sand mixture. This is then rolled or sprayed onto the existing plaster and flooring, allowing the old and new to connect.

Once the bond coat has dried, the plasterer can mix up a concrete mixture that will be troweled on to the existing pool surfaces. This plaster mix is generally a combination of white Portland cement, marble dust and water. It can then be rolled or sprayed onto the pool walls and floors and allowed to set up for a few hours or a few days, depending on the finish you choose.