Frequently Asked Questions
Gunite in and of itself is a mixture of cement, sand, and water applied through a high-pressure hose, producing a dense, hard layer of concrete used in building for lining tunnels and structural repairs. It originates from the word “gun” because of its hose application. Once dried in warm, dry conditions, it will become rock hard.
A gunite pool is built using three key elements. The first one is the rebar, the cage-like framework made of metal rods reinforcing the pool wall. This acts as the pool’s literal steel backbone, which may vary on levels depending on the depth.
Then comes the actual gunite that is shot onto the rebar across the entire excavated hole. This high-velocity spray-on technique makes the construction of uniquely shaped pools easier and sculpture-like.
As a finishing touch, the third material used for gunite pool construction is plaster. As the gunite cures or dries up, this material is spread across its surface, making it waterproof. This is the final coating that everyone sees and consists of cement, marble dust, and even colored quartz for added beauty.
Because of its application, gunite pools create a smooth swim surface with no lumps and bumps. On top of that, water slides, towers, and swim steps are often added to make an interactive, exciting water park right in your backyard. Gunite is also used to build private and public swimming pools and almost all commercial and residential spas.
A swimming pool is not only a costly and permanent investment, but it is also the central focal point of your backyard. Therefore, it has to be perfect to live up to such high expectations. The durability, unmatched beauty, and classic timelessness of a gunite pool cannot be matched by any other material, including fiberglass and vinyl liner.
Gunite has also gained popularity in the pool building industry because of its durability. It has a stable, steel-reinforced concrete structure that stands the test of time. In addition, most pool owners and construction companies prefer this type of material since its non-porous feature makes pools resistant to algae infestation.
With gunite, you will have an ideal building material for coping, steps, waterfalls, fountains, and virtually any structure that requires long-lasting beauty, strength, and cost-efficiency.
An inground pool is not just about splashing around in the water. It can also be an investment in your home’s overall value. For example, a 14 by 28 feet inground concrete pool can potentially add 5 to 8 percent to your property’s real estate value. This would mean that if your property is worth $500,000, your property’s value can increase from $25,000 to $40,000.
Gunite pools offer several advantages over vinyl and fiberglass pool construction. The use of gunite provides more strength and flexibility, and it is virtually maintenance-free.
It can withstand significant pressure such as frost heaving, freezing, expansion, and contraction due to temperature changes and large temperature swings without cracking or losing shape. This means that gunite pools can last for at least a hundred years, whereas fiberglass lasts around 25 years, and vinyl liner has to be replaced every five to nine years.
It must have realistic expectations with the type of pool you want to be installed in your home. As such, gunite pools and vinyl liner pools have their fair share of strengths and weaknesses. Consider the items below:
Pros of a gunite pool:
- can be in any size, shape, or depth
- more flexibility with design features
- aesthetically pleasing
- durable and lasts for a very long time
Cons of a gunite pool:
- more chemical use
- long installation time
Pros of a vinyl liner pool:
- low initial cost
- customizable shape and size
- non-abrasive surface
- does not foster algae
Cons of a vinyl liner pool:
- high lifetime cost
- high maintenance
- liner warranties are pro-rated
- low resale value
It is easy to change your existing vinyl liner pool into a gunite pool. With this option, you can even change the depth to your preference. From there, you can have the shape of your pool preserved using the existing walls.
This will allow you to add excellent pool features that usually cannot be installed in typical vinyl liner pools, including tanning ledges with umbrella stands, beach entries, poolside benches, seats, and raised water features. You can even remove a part of your current pool or do a complete overhaul and achieve the gunite pool of your dreams!
It can be a bit challenging to keep up with the many interchangeable terms in pool construction. In general, gunite and shotcrete are types of concrete. The difference lies in how they are all applied.
Concrete is a mixture of cement, water, sand, and either gravel or stone. When mixed, it forms a liquid that can be poured into a mold and placed under pressure to create the desired shape. As the concrete dries, it turns into rock-like material that is resistant to breakage and extremely strong.
In pool building, gunite and shotcrete come into play as their difference lies in when water is introduced into the mix. Shotcrete is the wet mix process where everything is already mixed, loaded in cement trucks, then delivered to your property. There, it will be applied manually by the crew.
On the other hand, gunite is the dry mix process. This means that the crew building your pool loads the dry cement (without water) into the delivery equipment. The water is then added to the dry mix at the nozzle of the hose at high pressure. Because of this pressure, the mixture compacts, and concrete is created right in the air before it hits the rebar.
The difference between these two materials is quite clear. Gunite is the cement shell that fills in the rebar framework and forms your new pool, while the plaster is the waterproof final coating that gives it a gleaming interior surface and a nice smooth finish. Thus, if you have a gunite inground pool, then chances are you have a plaster layer as well.
In general, too much chlorine or salt in any pool can cause damage. Saltwater can shorten the pool’s plaster finish lifespan since it is five times more abrasive on plaster than with ordinary chlorine water. Additionally, undissolved salt that sits on the pool floor immediately stains the surface.
The stickiness of the salt granules affects the time it takes to dissolve. In other words, the more sodium chloride on the granules, the faster they will dissolve in the water. You risk a slippery surface with too little salt but too much salt, and you have gone overkill. Balance is key. Take note that too much salt on your pool leads to other problems – specifically algae outbreaks and corrosion of metal objects like pipes.
With an average concrete strength of 3500-4000 psi, this material is excellent for exterior walls, foundations, and floors. Due to its high compressive strength, it is challenging to crush. However, its low tensile strength makes it vulnerable to cracking if you bend or pull it apart. This is why the rebar needs to be added: to reinforce the concrete for your pool walls and floor.
Providing the best support for the pool liner and ensuring that your new swimming pool has its proper shape, concrete pool shells should be constructed using a minimum thickness of six inches. This may be higher in some cases, depending on the engineer and soil conditions. On top of this, the plaster finish should include a minimum interior thickness of 3/8 inch.
Gunite has sufficient strength to support the weight of construction and swimming pool water. However, since it is not a homogenous material, it is not intended to be the water sealing media in pool construction. Instead, waterproofing is accomplished by filling the pool with a water-resistant lining, such as plaster, to prevent water from leaking out or seeping through.
Applying or curing gunite in near-freezing temperatures can affect curing strength and results in a sub-par swimming pool. That is why it is recommended to store, mix, apply, and cure gunite between 50° to 100°F as this temperature range produces the best results. In higher temperatures, gunite must be handled appropriately and at a recommended thickness to achieve adequate results.
We cannot emphasize enough that wetting the entire shell is critical to achieving the highest strength and minimizing absorption. It takes time for the residual moisture to evaporate from the water-soaked gunite slowly, but it needs time to do so, and this avoids trapping water in the gunite, which will cause it to absorb faster and weaken. Typically, wetting down the shell takes seven days. It is also imperative that the water quality used for wet down is considered, so your gunite pool remains strong and durable for years to come.
While many factors affect your pool’s energy usage, one contributor is the temperature of the water in it. It has been constantly proven that heating a material that holds liquid makes it keep the liquid warmer for much longer than if the pool were inlet into the air at ground temperature. A gunite pool is precisely that. This keeps your water temperature from dropping faster than the other outside air temperatures do.
The best-looking, longest-lasting paint for gunite pools is epoxy. An epoxy pool paint job will hold up to the elements and stand up longer than other kinds of pool paints. It wears thin without the annoying peeling and flaking that rubber paints fall victim to and is ideal for gunite or fiberglass pools. A good paint job with high build epoxy can last five to seven years.
Epoxy paint for pool surfaces can protect the concrete, plaster, fiberglass, or gunite in existing pools. While you cannot apply epoxy paint over resurfaced or old, deteriorated coatings, it is ideal for freshly poured concrete and plaster pools with no previous layer.
Gunite inground pools are vulnerable to popping out of the ground if the drainage is not done correctly. It is best not to DIY your way to draining your gunite pool. However, once it has been emptied, you should not leave it so for too long. This type of pool is drained mostly for repairs only. It should have a drain and filter where it can partially drain itself. It would be best if you used a pump to get rid of all the water altogether.
Curing time is critical to achieving a solid swimming pool shell. On average, gunite should be dried up for at least 28 days to make it stronger and more durable. However, since the curing time for concrete is not predictable, gunite is the preferred pool shell material. It has an established track record of producing more robust and more reliable pools with fewer returns.
Once the gunite pool has been poured, there are several ways to protect your investment. The most important one is to wait at least 24 hours before walking on your freshly cured gunite pool. But to make sure that your gunite pool is at its strongest, wait at least three days before walking on its surface.
Many people are afraid to have a gunite pool built in the rain. They do not want this type of installation because they think it could cause more leaks or damages than usual. In actuality, it is rare for gunite pools that have been built in the rain to encounter any particular issues. Even though it takes two or three days longer, there is no heavy evidence for these pools not to last as long as those built during fair weather conditions.
If your pool has been recently installed and you are experiencing cracks, the odds are that rebound gunite is the problem. The gunite should have appropriately incorporated the steel framework. If it did not correctly adhere to the rebar, the gunite “rebounds” or bounces back. Rebound gunite should be removed since it is fragile and lacks the structural integrity of standard gunite, making it more prone to cracks and other damages you would not want to have in your pool.
Gunite pools are a popular choice in areas with generally warmer climates. And if you have one, it is essential to keep it properly maintained for optimal use. Gunite pool maintenance includes leak inspection, weekly chemical testing (alkaline, chlorine, and pH levels), water level maintenance, daily pumping, and so much more.
One of the first steps in gunite pool maintenance is checking for leaks. Assemble the filter and the pump and do a test inspection before doing so in your actual pool. Do this every year to minimize the chances of surprise leaks.
Another thing that you should do is chemical testing. We suggest you hire someone to maintain the chemical levels in your pool since these levels have more of an impact on the overall quality of water than you may think. This includes the alkalinity, pH balance, and chlorine levels of your pool which helps prevent algae growth and other future sanitary problems.
Maintaining the correct water level of your pool is also something that you should not overlook. If you have an automatic water supply, this will not be much of a problem for you. However, if you do not, manually filling your pool with water using a garden hose would be just fine too. Just make sure to rebalance your chemicals each time.
Lastly, a pump runs almost continuously on certain days, but you cannot possibly turn it on for the entire day. How long you should run your pump depends on how often you use it and how warm your water is. Setting it for eight hours a day is generally sufficient for most pools to keep their chemicals adequately balanced.
Maintaining a gunite pool costs about $50 to $700 per visit and about $1,200 to $1,800 a year for regular cleaning and maintenance. Weekly visits can cost around $125 each, while monthly visits are at $150 each. These visits involve brushing and vacuuming the surface, cleaning and testing the water, emptying the skimmers, applying the right chemicals, and checking the filter. You should also expect to spend at least $75 for filter replacement.
The restoration of a gunite pool with small cracks will cost you around $75 per linear foot. With a contract for large spider web cracks, divots, and bulges, expect to spend $700 to $1,000 on a 150-square-foot pool. These prices depend on the size and condition of the pool, the surface finish, the type of interior finish, and the type of waterline tile.
The cracks in your pool are not necessarily a reason to panic—most often, they are not going any deeper than the plaster. This means that they do not typically cause leaks, but they can still make your algae problems worse or lead to calcium nodules. Fortunately, pool plaster cracks are fixable. Therefore, you can usually patch them up or find a better solution, such as completely re-plastering the pool to eliminate the gaps.
A power washer is a great way to keep your gunite pool clean. It is a device that helps you clean your pool and comes in various types, sizes, and power ratings. It helps get rid of all dirt particles and any accumulation of algae as it quickly deep cleans the pool surface.
Additionally, it prevents common problems like algae growth. However, it is never advisable to pressure wash a fiberglass or vinyl pool as this creates too much pressure on the plastic lining that can eventually cause damage.
Brush your pool and remove any algae from the walls once or twice a week. Cleaning your pool takes only about ten minutes unless you are taking on skimming tasks regularly. In which case, add extra time in brushing your pool.
Gunite pools are made more durable than most other pool surfaces because of their unique construction. In addition, because they are made up of aggregate materials bonded together with resin, it is possible to resurface a gunite pool without replacing the whole thing, saving you money and hassle. Typically, it takes seven to ten years before they should be resurfaced.
When it comes to pool resurfacing, most people prefer to have a professional take care of the work for them. However, while this may be the most convenient option, many people who have completed this project on their own have found that they appreciate the time spent. So, if you are handy with tools and are worried about the cost of having a professional perform the job for you, rest assured that pool resurfacing is within your reach whenever you want.
$6,500 is the national average for pool resurfacing, while labor varies from $45 to $65 an hour, depending on the work and location. The types of finishes available for gunite pools include plaster, paint, pebble, aggregate, and tile.
The cost of an average gunite pool installation in the U.S.A is approximately $30,000 and $65,000, which is $50 to $125 per square foot. This means a 20 by 40 feet gunite pool would cost $40,000 to $100,000. This does not include additional expenses for annual upkeep, including acid washing and re-plastering ($27,000 to $40,000).
Compared to fiberglass and vinyl layer pools, a gunite pool is, in general, more expensive. Its initial cost is $50,000 to $100,000 or even more while fiberglass only ranges from $45,000 to $85,000 and vinyl layer is the most affordable at $35,000 to $65,000.
Because of its significantly larger price, gunite pools may come off as an intimidating investment. However, there can be several ways for you to save money while still enjoying a solid, sturdy backyard oasis. One of the best things you can do is by looking at the bigger picture.
For instance, while vinyl liner pools offer an affordable initial cost, constant liner replacements and unexpected repairs may end up breaking your bank. With its high initial fee, you should be able to rest assured that what you are getting is the best with a gunite pool purchase.
Always go for the option that will save you money in the long term, not just at the moment. Just because you can save a few thousand dollars upfront does not mean buying the cheapest option. It makes more sense to spend a little more upfront and be sure that you will not be hit with unexpected bills later.
Gunite pools have high durability and come in just about any shape. As a result, they have become a prevalent trend, and it is easy to see why. Gunite pools are versatile, stylish, beautiful, and flexible. Plus, they offer a wide range of options to give you the most functional backyard oasis you have always dreamed about.