Gunite and shotcrete pools are popular choices for homeowners looking to enjoy a luxurious swimming experience. They’re both durable, low maintenance, and highly customizable. They may share many positive attributes, but it’s surprising just how dissimilar they are once you delve into further details. So here’s the big question we’ll be taking up for gunite vs shotcrete pools: what’s the difference?
Both are essentially concrete pool systems, using a combination of cement, sand, water, and air to create a strong mixture. The cement mixture is then applied on the pool wall and surface.
However, we’re not here to boast their similarities. We’ll cover the key differences between the two forms of concrete, their pros and cons, and factors to consider before installing a concrete-inground pool.
Gunite vs. Shotcrete Pools
Both gunite and shotcrete are building materials used for constructing swimming pools. But before we dive into their key differences, let us recap what characterizes each one.
What is Gunite?
Gunite – commonly referred to as spraycrete or dry-mix gunite – is a dry, concrete mix that comes out of the hose at a very high velocity and sticks to the pool surface wall and floor like glue. Pool builders will load pre-mixed concrete into a concrete hopper which feeds the material into the hose.
Following this, compressed air will push the dry mixture through the hose – responsible for pressurizing the mixture – and out of a gunite nozzle. The water and dry material mix at the last moment within the nozzle, right before the cement hits the pool surface.
Gunite adheres well to surfaces with varying shapes and curves, making it ideal for custom pool designs. It provides a smooth surface with a quick and easy clean-up. Overall, it’s a popular choice due to its strength, durability, and versatility.
What is Shotcrete?
On the other hand, shotcrete is classified as wet concrete that’s already fully mixed before it is shot out of a hose. It generally includes additional ingredients like bonding agents during mixing to facilitate better adhesion to surfaces.
When using shotcrete, pool building pros will load fully mixed wet concrete into a compatible hopper using compressed air (makes the shotcrete stick) to shoot the wet mix through the nozzle.
There is certainly a lot more information on gunite and shotcrete, but we don’t wanna spoil the fun of seeing them go head-to-head. Additionally, there will be sections dedicated to each of their pros and cons.
What Are Their Differences?
A great way to highlight their differences is to see them face each other on key factors that matter to future pool owners. These factors include the material type, installation process, durability, and price.
| Gunite | Shotcrete |
| Dry-mix of sand and cement | Wet concrete mix |
| Uses compressed air to spray the mix | Mix is applied via high-pressure water hose |
| Slow installation process to ensure proper application of the sand and cement mixture. It can be applied any time of the year. | Quicker installation process due to wet concrete mixture (pre-made). It cannot be applied in freezing temperatures |
| Can stop and restart construction process as needed | Pool construction needs to be done in one day before letting it cure |
| Less prone to to water damage due to their dry-mix composition | More susceptible to water damage |
| Repairing gunite pools is easier and less costly | More costly and complex repairs |
| Difficult to mix the correct water ratio, higher chance of errors | Pre-mixed forms of concrete carry lower risk of application errors |
| Compressive strength of about 9,500 psi | Compressive strength ranges from 6,500 to 7,500 psi |
In the upcoming section, we will highlight the pros and cons of each material separately. This will give you further insight into what you might potentially invest in.
Pros and Cons of Gunite
Pros
✓ More affordable application process than shotcrete
✓ Suitable for warm climates and commercial pools
✓ Stop and restart application without weakening the pool structure
✓ Highly durable with the ability to withstand wear and tear for many years
✓ Material can be formed into any shape or size (high versatility)
✓ Small cracks or chips are easily patched. You won’t need to replace the entire system
Cons
✗ Requires highly skilled pool builders and certified nozzle operators (yes, that’s a thing!)
✗ Any errors in ratio (dry-mix concrete and water) can disrupt the application process and quality
✗ Hose can get clogged by the dry concrete mix
✗ Very messy process. Gunite produces a lot of over-spray or rebound, which is excess gunite that hasn’t stuck
✗ Gunite takes a long time to install (weeks or months to get done)
✗ Susceptible to cracking under pressure
It’s quite interesting to see how some of the cons diminish some of gunite’s advantages. The ability to stop and restart gunite applications is great, but you’ll have to deal with a very messy end-result. It can also take a long time to install, testing the patience of many homeowners.
Gunite may form cracks under pressure, but they can easily be patched. That’s an advantage that cancels out one of the cons.
You may be wondering why gunite application costs less than shotcrete, despite the fact that it takes more time and requires certified operators. It is one of the disadvantages of shotcrete that makes gunite more affordable. So what are the advantages and drawbacks of shotcrete?
Pros and Cons of Shotcrete
Pros
✓ Nozzle operator doesn’t require high technical skills as with gunite
✓ No need to worry about the ratio of dry-mix to water
✓ Quick installation process with minimal curing time required
✓ Shotcrete requires less equipment and produces less rebound during spraying
✓ Shotcrete is denser and more resistant to cracking
✓ Shotcrete allows for more precise customization because it can be applied in layers
✓ Can last for decades with minimal upkeep cost
✓ Suitable for areas prone to earthquakes or shifting soils
Cons
✗ Premixed cement must be applied quickly. You cannot stop and restart similar to gunite
✗ Cracks may form if premixed concrete is mixed with too much water
✗ Can only be applied once and correctly by a certified nozzleman
✗ Narrow time window makes shotcrete more expensive than gunite
✗ Vulnerable to shrinkage if excess water mixes with concrete
✗ Some pool companies may lack the expertise for a quick and efficient shotcrete application
One of the major drawbacks of shotcrete is the importance of getting the job done right in one day. Building a pool in such a limited timeline requires highly efficient pool contractors, which justifies the high cost. But let’s look at the glass half full.
Shotcrete doesn’t involve the risk of messing up the dry-mix to water ratio, nor does it rebound when sprayed on a pool wall or floor. It also gives you more customization possibilities, with the only limit being your imagination. Finally, it can last for decades with low maintenance costs.
Factors to Consider Before Installation
It’s never good to rush home improvement projects, especially swimming pools. Before deciding on which material is best for your new pool, you must first consider the factors associated with such a major investment:
- Pool surface finish: Whether you choose gunite or shotcrete, you must pick a type of finish for your pool surface. Primary options include plaster, aggregate, and tile. Plaster is the most popular and least expensive option, but can be rough on the skin. Tile is the most expensive and luxurious surface material.
- Ground excavation: An in-ground concrete pool construction cannot be done without ground excavation. This is an additional cost that is not included in the price of the pool. For both shotcrete and gunite, plumbing will need to be installed in proper places, followed by steel rebar to support the concrete.
- Size: As with every other pool type, the size will affect the total cost of installation. Pool size is an important decision if you want to install other structures around your pool, or need to allocate space for other backyard activities.
- Acid washing: Concrete pools are prone to algae growth, and require regular maintenance. You’ll need to perform an acid wash every 3 to 5 years for a squeaky clean pool. The cost of acid washing is between $535 and $1,775.
- Hiring pool pros: Applying gunite and shotcrete requires experienced and professional pool contractors to avoid improper installation. Be sure to hire certified nozzle operators by the American Concrete Institute. You can find more information on the official webpage of the American Shotcrete Association.
- Budget: Gunite is typically more affordable than shotcrete, but both materials cost a lot more than other pool types, such as vinyl liner. Concrete pools are considered luxurious and expensive, so be sure to allocate a proper budget for such a project.
Should You Choose Gunite or Shotcrete?
Shotcrete is best if you’re over-excited and want the new in-ground pool installed as soon as possible. Shotcrete needs to be applied quickly within a single day before letting it cure, so you’ll test out your new swimsuit in no time. Gunite is a good choice if you’re not in a rush, and more focused on installing a quality pool for a lower price. You’ll get a smooth pool finish with no cracks.
More importantly, your choice strongly depends on the pool company or pros near you. Some contractors may have more experience applying gunite rather than shotcrete, or vice versa. You’ll need to hire the right pool experts for what you need. Be sure to check on their experience levels and certifications.
If you’re confused, established pool contractors can assist you with selecting a material that fits your needs and budget.
Ultimately, the final choice is yours. Both can last for decades if properly maintained, so you’ll need to decide based on your budget, preferences, and time frame.
FAQ About Gunite and Shotcrete Pools
To counter the growth of algae, some pool owners may perform acid washing more frequently than needed. This may lead to cracks forming on your concrete pool, and can be fixed by replastering. The cost of replastering ranges from $2,500 to $13,000, and is required every 10 to 15 years.
Concrete pools typically cost more than other popular pool types. The list below shows the different in-ground swimming pool prices:
● Vinyl Liner: $24,000 to $44,000
● Fiberglass: $24,333 to $70,000
● Gunite/Shotcrete: $31,000 to $71,666
To obtain a solid structure, a concrete pool shell requires a minimum thickness of 6 inches, excluding the plaster. The thickness of the pool wall and concrete base determines the pool’s durability. The thicker the pool shell, the less it is prone to cracking.
Build Your Luxurious Backyard Retreat
Both gunite and shotcrete will provide you with a high-quality, durable swimming pool. Concrete pool owners enjoy years of swimming without worrying about repairs or regular upkeep.
Working with shotcrete and gunite is certainly not DIY-friendly. Even if you have some experience installing above-ground pools or fixing minor pool issues, concrete pools are on a whole other level. Pool pros that work with shotcrete and gunite need to be certified and skillful in getting the water to dry mixture ratio right. Errors while spraying concrete could be costly and irreparable.
You want your pool built right, and you need a professional pool builder to do that. Pool Gnome connects you to the best pool builders near you. With just a few clicks, you’ll get quotes in minutes.
Main Photo Credit: Jeff Clow / Canva Pro / License
