The pool is the centerpiece wherever you go, be it a country club, a backyard, or a park; so, it is important to keep it looking well manicured and inviting. While it is fairly easy to keep the water looking clear and clean through daily and/or weekly maintenance, inside the pool is a different matter. Many people just paint their concrete pools because it appears to be cheaper at first, but a pool plaster and resurfacing is a better, cheaper, and more attractive long-term solution.
What is Pool Plastering?
Pool plaster is a waterproof shell that protects the concrete interior of the pool from the water to increase the pool's longevity, prevent erosion, and stop leaks. Typically, plaster comprises some combination of these five chemicals:
Also known as Alite, this is one of the two minerals present in many types of cement. It provides the early strength for the plaster as it dries and produces calcium hydroxide when mixed with water.
Commonly referred to as Belite, this chemical is the most important of the bunch. It also reacts with water to form calcium hydroxide, and in doing so hardens bonds, creating the plaster's final form. It is extremely water resistant and supplies the strength for the resulting plaster.
This is the chemical used mostly for the pre-mix aspect of the plaster. It is essential for the heating and drying of both the mixture and the final product. However, it is best used in low amounts because it is responsible for many of the negative aspects of plaster if used in higher quantity, such as a shorter life span, and a more porous finish.
Tetra Calcium Aluminoferrite
This is the key ingredient in plaster that separates it from a basic concrete. It is very water resistant and provides the plaster with a nice smooth finish, and a reliable and durable water resistance.
This is the chemical created by some of the above chemicals interacting with water. Because it is soluble in water, it can lead to erosion and streaks in the plaster, but it is necessary to create the strong bonds from the other chemicals.
Why Is It Important?
Pool plaster (or paint) is important because it prevents the water from eroding and leaking from the pool, and either into the surrounding earth, or into the concrete base of your pool. People consider concrete pools more luxurious than their vinyl counterparts, but one drawback is that they need resurfacing more often, which is usually more expensive.
Without pool plaster or paint, a concrete pool can still hold water for a short amount of time, but it will quickly crack and fall apart. Therefore, some surface is a requirement for any concrete pool owner. Resurfacing is equally important as cracks or erosion in your paint or pool plaster can quickly lead to either pockets eating at your concrete, a cracked, aged and unattractive appearance, and eventually damage to the underlying concrete structure.
Painting vs. Plaster Resurfacing
There are two main ways of water proofing your concrete pool: painting and plastering. Both have pros and cons, and both work in the short term for protecting your concrete and holding water. To determine what is best for you, we will breakdown the following:
Pool plaster is far and above the better choice for those looking for a one-time, long-lasting solution to pool surfacing. A well mixed, applied and maintained plaster can last anywhere between 15 to 20 years. During this time, small cracks may appear in your plaster, but these are not an issue as long as you can get a professional to clear them.
Paint usually lasts anywhere between 2 to 7 years, meaning you usually have to reapply a painted coat at least three times during the lifetime of one coat of plaster. However, it is easier and cheaper to do so. Cracks in paint should immediately be looked at as it may be a crack in the underlying concrete and not just the surface paint level.
Pool Plaster is usually about a half-inch think, creating a barrier that completely seals out water from the underlying concrete. While it does occasionally crack and erode slightly, it still prevents water from burrowing and damaging the underlying concrete structure. Plaster is by far the most durable option.
Unlike plaster, paint doesn't create a thick layer between the concrete and the water. It acts as a thin, waterproof layer and compares to the water-resistant sprays that many stores sell for clothing. Therefore, any wear or crack in the paint will inevitably lead to damage to the underlying concrete, and thus paint is usually considered less durable.
Plastering, or resurfacing a pool, takes a lot of prep work. The plaster has to be mixed professionally and then left to form the right bond before applying to the pool. Plaster takes more work and cannot be bought/created by the average pool owner, as every step of the process requires professional knowledge. If the pool has previously been painted, it will take an extra step, as the remaining paint residue has to be blasted off.
Paint has almost little to no prep work. A pool owner can go to a local pool store and usually purchase the paint needed to coat their pool and even paint it themselves. It takes little to no professional knowledge and as long as the concrete is exposed, a pool can be painted even if it was previously plastered. However, it one should note that different pool paints are not compatible, so you need to buy the same paint that was previously used.
As mentioned above, plastering requires professional knowledge and skill to apply properly. Further, it is important to apply correctly as an incorrect plaster application can lead to having to do the whole process over again, which is very expensive. Plaster usually also takes slightly longer to set than the paint does to just dry.
Paint can either be applied professionally, or by the pool owner. Multiple layers are recommended to create a more durable and protective coat, but if a spot is missed, it is easy to go back and add paint to a section, or add another layer. Therefore, paint is the easier of the two to apply to your concrete pool.
Plaster usually creates a deeper, more lustrous appearance over paint. It also usually keeps its pristine appearance longer than paint and can be lightly acid-washed two to three times in its lifetime to restore a new appearance. However, make sure this is professionally done, otherwise it can lead to erosion in the plaster.
Paint usually looks just as good as plaster when freshly applied though it usually looks more shiny and reflective. However, paint loses its shiny appearance quicker than plaster loses its luster and must be reapplied to bring back the new, fresh shiny look.
Both plaster and paint are easy to customize by just adding pigment and color into the mixtures before they are applied, though paints allow more customization as you can mix and match different colors and patterns while painting your pool.
If professionally and correctly applied, professionals consider plaster a more reliable option as it creates a thick barrier between the concrete and water. However, it is possible for plaster to fail shortly after application and then a whole new mixture must be made and then applied.
Paint is almost as reliable if applied by a professional, but because some pool owners try to do it on their own, they often have areas where the paint is thin or incorrectly applied. However, the situation is easily remedied as just another coat of paint needs to be applied instead of having to start the whole process over.
To resurface or plaster a pool will usually cost somewhere between $6,000 and $10,000. The reason behind this high cost is that the mixture has to be created specifically for your pool and the mixing and application has to be done by a professional. However, remember that this process is only done every 15 to 20 years, so it costs more upfront but maybe just as expensive or even cheaper in the long run.
Painting a pool usually only costs around $1,000 plus any labor if you want to hire a professional. However, if you consider that you have to paint 3 to 4 times in the lifetime of plaster, it becomes just $1,000 less than the plaster job, and that is without adding in labor costs and the cost of emptying and refilling your pool.
In conclusion, if you can afford it, plastering is usually the better option for any pool owner, but if the high upfront cost is too much, or you want to do it yourself, then painting the pool might be the better option for you. If you have questions, or if you are looking to paint or resurface your pool, contact any local pool store for more information.