How Thick Is Pool Plaster?

Written by Michael Dean
September 28, 2023

measuring thickness of pool plaster

Many pool owners opt to use pool plaster as the finish for their pools because it is durable and has a ton of color and design options (and it’s more cost-effective over the long term). Plaster is a smooth, hard coating applied to a pool’s interior. Understanding how thick pool plaster should be will allow you to extend the life of your pool. So, how thick is pool plaster?

Main Takeaways

  • Pool plaster is a smooth, durable, cost-effective option for pool finishes.
  • Pool plaster is around 3/8″ thick.
  • The thickness of pool walls is usually between 6-8 inches for in-ground pools and 4-6 inches for above-ground pools.
  • The life expectancy of pool plaster is around 7-20 years. However, this can vary depending on the type of pool plaster, the climate, and the level of care.

How Thick Is Pool Plaster?

The thickness of pool plaster can vary, but on average, pool plaster is about three-eighths of an inch thick. The thickness of the plaster will depend on the type of plaster used and the size of the pool.

The size and depth of the pool are the most important factors when calculating the thickness of pool plaster. The plaster needs to be thick enough to withstand the weight of the water and the wear and tear of normal pool usage.

The plaster must be at least three-eighths of an inch thick for inground pools because they tend to be larger and deeper than above ground pools. Conversely, above ground pools typically don’t require as much plaster because they’re not as deep. The average above ground pool is only about four feet deep, so the plaster can only be about a quarter of an inch thick.

There are two main types of plaster: white cement plaster and aggregate-based plaster.

White cement plaster is generally thinner than aggregate-based plaster because it doesn’t have as many ingredients.

Aggregate-based plaster is made from a mixture of portland cement, water, sand, and small stones, pebbles, or gravel. This type of plaster is usually thicker than white cement plaster due to the additional components that make up the plaster. Aggregate-based plaster is also more durable and resistant to cracking.

How Durable is Pool Plaster?

Plastering your pool will make it last longer and look better. This is because the plaster acts as a barrier between the water and the pool walls. Plaster helps prevent the pool walls from staining and fading. It also protects the pool from damage caused by chemicals and other elements.

When plastering your pool, ensure that the plaster is the right thickness. If the plaster is too thin, it may peel quicker. If the plaster is too thick, it may crack and be harder to apply.

With the right thickness, pool plaster can last for many years. The average lifespan of pool plaster is 7 to 20 years. However, this will depend on the type of plaster, the climate, and the level of care.

The most durable type of swimming pool plaster is quartz and tile finish. These can last for 20 years or more. But again, you need to take proper care of it to make it last this long.

Here are some of the best practices for caring for your pool plaster:

  • Brush the walls weekly
  • Use a pool cover
  • Maintain proper pH levels
  • Circulate the water

Avoid using harsh chemicals or cleaners on the plaster, and take care when brushing to not scratch or damage the plaster. With proper care and maintenance, you can extend the life of your swimming pool and enjoy it for many years to come.

How Thick Should Pool Walls Be?

The thickness of pool walls depends on a few factors, including the type of pool, the climate, and the soil conditions.

Inground pools in colder climates should have thicker walls to insulate the pool better and keep the water warmer. The thickness of the inground pool walls also depends on the soil type. Soil that is sandy or has a lot of clay can erode over time, so the pool walls need to be thicker to compensate for this.

Above ground pools typically have thinner walls as they don’t need to be as durable. The climate is also not as big of a factor for above ground pools, so they don’t need to be as well insulated.

The average thickness for inground pool walls is 6-8 inches. For above ground pools, the average thickness is 4-6 inches.

No matter what type of pool you have, the walls must be thick enough to provide the necessary support and durability.

I drew this diagram below to give you an idea of how pool wall thickness and plaster play a role in your complete pool structure.


  1. Rebar
  2. Waterproof membrane
  3. Soil
  4. Gravel backfill
  5. Drainage system
  6. Excavated base
  7. Gravel bed
  8. Slab foundation with insulation
  9. Rebar
  10. Pool floor concrete
  11. Joints to connect floor to walls
  12. Footing
  13. Walls
  14. Lighting
  15. Plaster
  16. Tile (optional)
  17. Coping

As you can see, the pool wall and plaster are just two components of the structure with lots of support behind them – rebar, a waterproof membrane, and several foundation layers.

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Frequently Asked Questions

What is the life expectancy of pool plaster?

The life expectancy of pool plaster can range from 7 to 20 years. However, the actual life expectancy can vary depending on the type of pool plaster, the climate, and the level of care.

What is the most durable pool finish?

The most durable pool finish is quartz and tile. Quartz is an engineered stone composed of 93% quartz and 7% resin. It is one of the hardest surfaces, making it a perfect choice for high-traffic areas such as your pool deck. Tile is also a very durable option for pool finishes. It is impervious to water and can last for decades with proper care.

Questions? Let me know.

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