Gunite vs. Concrete – What’s The Difference?

In the United States, many homes in warmer states have swimming pools. There are many different types of pools and if you are having a new pool built there are a number of factors you will need to consider such as the location of the pool, the design of the pool, and the materials that will be used during the construction process.

For inground pools, you will need to decide what type of pool you would like before hiring an appropriate pool builder.

If you decide to have a concrete pool built you will have to choose between two of the most popular materials that are used, being concrete and gunite.

While the construction crew may have a preferred construction method and material, as a pool owner you have a valid choice in this decision as different concrete materials will suit certain budgets and timeframes better than others.

When looking for a pool builder it is important that you choose a team that is American Concrete Institute (ACI) certified as working with concrete requires a highly skilled worker to achieve good results.

To make an informed decision regarding the pool construction it is important that you know the difference between these two popular pool building materials as well as knowing which one will help you to achieve your desired finished product.

What is Gunite?

Gunite is essentially a type of concrete that requires the addition of water to be added on-site before use. It is a dry concrete mix that is often used in pool construction to form the shell of the pool.

The dry mixture is sprayed over a rebar framework through a high-pressure hose that is manned by a nozzle operator. The material shoots out at a high-velocity meaning the spray nozzle needs to be operated by a skilled professional.

A heavy coating of gunite is applied and left to set before the next step begins.   

Gunite is a popular choice for pool designs of different, more complex shapes. The pools are designed on-site giving the owner ample opportunity to alter designs during the construction process. Often, gunite pools are topped with vinyl, fiberglass, or other plastic finishes to achieve a smooth finish, which is popular with most pool owners.

Gunite can also have tiles applied over it, giving the pool owner plenty of options with how they want to finish their pool. 

The dry gunite mix has a number of advantages and disadvantages that should be considered when deciding whether you should use this material during the construction of your in-ground pool. 

Advantages:

  • Gunite is a very flexible material 
  • Gunite is typically less expensive than concrete
  • The application process can be stopped at different stages allowing it to work to a timeframe or any budget issues that may arise
  • Gunite is a very sturdy material and is a more water-tight material than concrete
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Disadvantages:

  • Additional maintenance is required for gunite pools as they have a porous surface, which increases the risk of algae growth
  • The dry mix can clog pipes which can be costly to repair
  • All of the mixing process takes place on-site which can make the construction site larger as workers will need space to mix the Gunite and load it into the sprayer unit.

What is Concrete?

Some may be surprised that plain old concrete can be used to build the shell of an in-ground pool. Concrete is made from a mixture of cement, sand, stone or gravel, and water. When using concrete in pool construction often one of two methods will be used, being a dry-mix or a wet-mix process.

The wet-mix process is the most common and it is often referred to as shotcrete. Shotcrete pools are built with a consistent and strong coating but the concrete surface can be rough, meaning it is not often used as the final pool walls.

Another material or pool lining, such as vinyl, is used to give the pool walls a smooth surface.

Similar to the dry gunite mix, concrete also has a number of advantages and disadvantages that should be considered when deciding whether it is the right choice for you to use when building an in-ground pool. 

Advantages:

  • Concrete takes less time to install than gunite and may better suit constructions that have a shorter timeframe
  • Concrete is suitable for any climate 
  • All of the mixing process takes place off-site and is delivered in a cement truck

Disadvantages:

  • The metals and alkaloids from the concrete can spread into your pool water through the plastic filter and so filters in the pool must be cleaned often
  • Concrete is more expensive than gunite
  • Water is sometimes added when the concrete is being delivered to prevent it from hardening but this may affect the strength of your concrete and ultimately lead to cracks when the concrete has been poured and hardened
  • Concrete must be poured in one go to prevent creating any weak points

What is the difference between Gunite and Concrete?

The main difference between gunite and concrete is the method that is used to apply these materials to the framework of the pool. Concrete is poured and gunite is sprayed.

The pouring of concrete is faster than the spraying of gunite.

Both methods require skilled professionals. Another difference is their composition. Gunite is made up of fine particles rather than the mix of large and small particles that would be found in concrete.

Which is better, Gunite or Concrete?

The best option may vary depending on your pool project and other influencing factors. If you have a smaller budget than gunite would be the best choice but you will need a longer timeframe for this construction project when using gunite.

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Concrete suits pool projects that have a larger budget. Although it is more expensive than gunite this may be worthwhile for your project to be completed in a shorter time frame. 

If your pool is being built in a complex shape gunite may be used as it is a free form and can easily be molded to different shapes. If your pool is a less complex shape that can be poured in one go then concrete can be used.

When working with concrete it is more complicated to stop the pouring process. You should consider your desired end result as well as time and budget when deciding which material would best suit your pool project.

Speak with trade professionals for their invaluable insight to help with your decision.  

Final Thoughts

The bottom line is that both gunite and concrete have their benefits but both equally have downsides. Each in-ground pool is unique and the concrete material that is best for you may vary from what was best for others in your neighborhood.

Whether you use gunite or concrete both will result in a durable, water-tight swimming pool.

FAQs

Is gunite better than shotcrete?

Gunite has more benefits than shotcrete. It will provide a smoother finished surface as well as being easier to spray and being more durable than shotcrete. The nozzle used to spray shotcrete is heavier than the spray unit that is used to apply gunite to the framework of the pool. 

How long do gunite and concrete pools last?

If you have your pool constructed properly, a gunite pool could last as long as 100 years. If your pool is poorly constructed, cracks are likely which would lead to expensive repairs. Concrete pools do not last as long with poorly constructed pools lasting as little as 10 to 15 years and well made pools lasting up to 50 years.

What is better concrete or fiberglass pools?

Fiberglass pools are often more visually pleasing than concrete pools. Fiberglass pools give a smoother finish due to the gel applied over the raw fiberglass. Concrete pools are usually tiled which is ultimately not as smooth as a fiberglass pool. Fiberglass pools are more expensive to install but they are very durable and strong.