Pool Plaster | A Complete Guide to the Foundation of a Beautiful
When it comes to swimming pool finishes, pool plaster remains one of the most popular and trusted materials used in both residential and commercial pool construction and renovation. Known for its smooth texture, clean aesthetic, and durability, plaster plays a critical role in maintaining the integrity and appeal of an in-ground pool. However, while many homeowners admire the look and feel of a well-plastered pool, few understand its proper function, benefits, maintenance requirements, and the available options.
In this comprehensive guide, we’ll explore everything you need to know about pool plaster—what it is, how it’s applied, the different types, signs of wear, and how to properly maintain it to ensure your pool remains a refreshing oasis for years to come.
What Is Pool Plaster?
Pool plaster is the final layer applied to the interior surface of a concrete or gunite swimming pool. It serves two primary functions: waterproofing the pool shell and providing a smooth, attractive surface for swimmers. Traditional pool plaster is a blend of white cement, fine marble sand, and water. When mixed and applied correctly, it creates a hard, durable surface that is both functional and visually pleasing.
This plaster coating typically ranges from ¼ to ½ inch thick and is applied to the pool surface in a skilled, labor-intensive process. Once cured, it creates a watertight seal and gives the pool its iconic smooth, white appearance, or other colors and textures depending on the finish selected.
Why Pool Plaster Is Essential
Although it might appear decorative at first glance, pool plaster is far more than a cosmetic finish. Its importance to the overall health and functionality of your pool cannot be overstated.
Waterproof Barrier:
While concrete and gunite are strong structural materials, they are porous and can absorb water. Plaster seals these surfaces, preventing water from seeping through and causing long-term structural damage or underground leaks.
Comfortable Swimming Surface:
The smooth, polished finish of plaster is gentle on swimmers’ feet and hands. Unlike rough aggregate or unfinished concrete, plaster offers a silky feel that enhances the swimming experience.
Aesthetic Appeal:
Pool plaster adds visual elegance. White plaster gives the water a classic, sky-blue hue, while colored or textured finishes can provide a modern or tropical look.
Chemical Resistance:
When maintained properly, plaster resists damage from pool chemicals and maintains its integrity over time. It acts as a buffer between the pool water and the underlying structure.
Different Types of Pool Plaster Finishes
While traditional white plaster is still widely used, homeowners and designers now have a variety of plaster finishes to choose from, each offering unique benefits and visual effects.
White Plaster:
This is the most classic and economical option. Made with white cement and marble dust, it gives the water a clean, light blue appearance. Its simplicity and affordability make it ideal for homeowners on a budget.
Colored Plaster:
By adding pigments to the mix, plaster can be customized in a range of shades, including blue, gray, tan, and even black. These finishes create deeper, more dramatic water tones but may show wear and unevenness more quickly than white.
Quartz Plaster:
A blend of plaster and crushed quartz, this finish is more durable and resistant to stains. Quartz is harder than marble, making it a better choice for pools that receive heavy use. Quartz finishes are available in a wide range of colors and are renowned for their durability.
Pebble Plaster (Aggregate):
This high-end finish mixes plaster with small river pebbles. The result is a highly durable and textured surface that can last 15–20 years or more. Pebble finishes are available in various colors, providing a natural, lagoon-like aesthetic.
Polished Aggregate Finishes:
These finishes combine plaster with glass beads or quartz that are polished to a smooth finish. They offer a luxurious sheen, outstanding durability, and a unique visual depth, albeit at a premium price.
How Pool Plaster Is Applied
Applying plaster is a highly skilled task that requires experience and precision. Here’s a general overview of the application process:
Surface Preparation:
The existing pool surface (whether it’s new concrete or an old plaster layer) is cleaned and prepped. In the case of replastering, old plaster may be removed or roughened to ensure the new layer bonds properly.
Mixing:
Plaster is mixed on-site, using a precise ratio of white cement, sand, water, and optional pigments or aggregates.
Application:
The plaster is sprayed or troweled onto the pool surface and smoothed by hand using steel trowels. The finish must be even, with no air pockets or tool marks.
Curing:
Once applied, the pool is immediately filled with water to begin the curing process. This helps prevent shrinkage and cracking. The water chemistry must be closely monitored during the first week to avoid damaging the fresh plaster.
Signs Your Pool Needs Replastering
Even the best plaster finish will eventually show signs of age. Most plaster finishes last between 7 and 10 years, though quartz and pebble finishes may last longer. Here are some signs that your pool may need replastering:
- Surface Roughness: If the surface feels rough, it’s a sign the plaster is deteriorating.
- Discoloration and Staining: Dark spots or blotches can indicate chemical damage or algae infiltration.
- Cracking or Chipping: Small cracks may lead to more severe structural issues.
- Spalling and Delamination: When the plaster begins to peel or flake off, it’s time for resurfacing.
- Visible Rebar or Concrete: Exposed substrate is a major issue and must be addressed immediately.
Maintaining Your Pool Plaster for Longevity
To get the most life out of your plaster finish, proper care and maintenance are essential. Here are some maintenance best practices:
Balance Your Water Chemistry:
Maintaining appropriate levels of pH, alkalinity, calcium hardness, and sanitizer is critical. Poor chemistry can erode plaster, cause etching, or lead to the formation of scale.
Brush the Pool Weekly:
Brushing helps remove dirt, algae, and calcium deposits that can stain or wear the surface.
Regular Filter Cleaning:
A clean filtration system keeps debris and minerals from circulating and damaging the plaster.
Avoid Metal Tools or Harsh Cleaners:
These can scratch or stain the surface. Use pool-safe cleaning products and accessories.
Schedule Regular Inspections:
Having a professional inspect the pool annually can catch small problems before they become costly repairs.
Cost of Pool Plastering and Replastering
The cost of pool plastering varies depending on the size of the pool, the condition of the existing surface, the type of plaster chosen, and your geographic location. On average:
- White Plaster: $4 – $6 per square foot
- Quartz Finish: $5 – $8 per square foot
- Pebble Finish: $7 – $10 per square foot
- Polished Aggregate: $10 – $15 per square foot
A standard 20’ x 40’ pool (800 sq. ft.) may cost between $3,200 and $12,000 or more for a complete replastering job.
Conclusion
Pool plaster is far more than a cosmetic finish—it’s the very foundation that keeps your pool structurally sound, watertight, and visually inviting. Whether you’re building a new pool or restoring an older one, choosing the right plaster finish and maintaining it properly can make all the difference in longevity, aesthetics, and swimmer comfort.
With various finishes available to suit different budgets and design goals, and with the guidance of experienced professionals, you can ensure that your pool remains a shimmering centerpiece of your outdoor space. Don’t wait for cracks or stains to take away from your enjoyment—invest in high-quality pool plaster and preserve the beauty and performance of your pool for years to come.