What is a Gunite Pool?
A gunite or shotcrete pool is formed by shooting concrete through a high pressure air hose over steel reinforcement bars. After the concrete is allowed to cure, it forms a highly durable pool sheel that lasts decades.
Gunite Pools Are The Most Popular Pool Type In America
If you’re a homeowner considering buying an inground swimming pool, you may have already encountered the term “gunite” during the course of your research. What exactly is gunite? How is gunite different from concrete? What is shotcrete, is that the same as gunite or something altogether different? We discuss the details and answer all the questions in this informative article about Gunite Pools.
Gunite pools typically offer much more design flexibility and aesthetic quality than fiberglass or vinyl liner pools. In this article we examine what gunite really is and provide some basic facts about the material. We also discuss how gunite is used in pool construction, how it relates to shotcrete, and the advantages and disadvantages of both.
3 Takeaways About Gunite Pools
- Gunite is a concrete blend of cement, sand and water that’s applied or shot through a high-pressure hose. After curing (drying), gunite becomes rock hard solid structure.
- After a hole is excavated for a new pool, crews install a network of steel bars, known as rebar to form a metal skeleton that extends throughout the entire stretch of the pool area.
- Gunite crews spray the concrete blend at high velocity onto the steel reinforcement across the entire pool, creating a dense pool floor and thick walls. Gunite pools can be formed into nearly any shape.
What is Shotcrete, is it any different than Gunite?
Ok, the key takeaway here is that gunite and shotcrete are both a form of concrete. The term gunite is more widely referenced in terms of swimming pools. However, it’s important to note that gunite is actually a type of shotcrete.
FACT: Gunite is actually an offspring of shotcrete. The only differentiation is how they are prepared. Gunite is a dry mix—with water added at the job site; shotcrete is premixed beforehand and ready to go. Shotcrete also contains gravel, whereas gunite will not.
What Happens After Gunite Is Applied?
After the gunite is allowed to properly cure it can be plastered. There are options of high-end pebble plaster as well for a luxury texture. The plaster is actually what waterproofs a gunite pool. Plaster is also the final coating that everyone sees in the pools interior surface.
Other Elements That Go Into Building A Gunite Pool
The three main components of building a gunite pool are cement, steel and plaster. However, there are many other phases that comprise building a gunite pool, including tile, plumbing, electric, and perimeter coping. Below is a rough outline of the 10 phases that comprise building a gunite pool.
10 Phases To Building A Gunite Pool
- POOL DESIGN & PROPOSAL
- OUTLINING THE POOL AREA
- FORMS & EXCAVATION
- REBAR & STUB-OUT
- SHOOTING GUNITE (SHOTCRETE)
- PLUMBING & EQUIPMENT
- TILE & COPING
- PLASTER & START-UP
1. Pool Design & Proposal
The process first begins with meeting with a pool contractor / pool designer. Your builder may perform designs themselves or have pool designers on staff with experience in creating backyard designs that compliment and blend in with the surrounding natural elements of your home. Typically, a pool designer will work with you to understand your vision, budget, and details. They may suggest improvements, upgrades, and features that will enhance your pool to compliment your lifestyle.
After approving the final pool design and budget the pool designer normally will meet with you again to finalize the contract. Your pool contractor will then submit a properly scaled and rendered set of plans to your homeowners association and the local city permit office for approval before actual work may commence. Once receiving approval on a permit, work can begin. This is when men with trucks will begin showing up to your home at regular intervals.
3. Outlining The Pool Area
Your pool contractor will outline the entire perimeter of the pool excavation area with spray paint. This will serve as a stencil for the overall shape and circumference of the pool. It’s also the prime opportunity to make any signficant changes to the design plan before excavation takes place. Keep in mind, that any changes will impact the overall plan and make impact the permitting process.
4. Forms & Excavation
The next step will involve breaking ground with the heavy pool excavation equipment. Provided there is proper access for the machinery to get in and out of your yard, this should be a 1 or 2 day process to actually dig the pool area. If access is a problem fencing may need to be removed in order for heavy machinery to get in and out of the yard. Typically however, it takes approximately one full day to properly excavate a swimming pool in preparation for the structural reinforcement stage.
5. Rebar & Stubout
For gunite pools the reinforced steel beams of the pool are what will help to connect the outer decking slabs. Water weighs 62.42lbs per cubic foot, and will apply pressure per cubic foot against the bottoms and sides of the pool. When the swimming pool is full of water there are tremendous outward pressure against every single point of the pool structure. The steel skeleton will structurally reinforce the shell of your swimming pool.
Once the structural steel is built into the desired shape of the pool, the pool contractor will install the stub-out plumbing. Referring to the initial pool plans for the proper placement of: return jets, water features, suction lines, and spa plumbing systems – these stub-outs are precisely placed to adhere with the overall plan of the pool.
6. Shooting Gunite (Shotcrete)
At this juncture your pool contractor will install the gunite structural shell of the swimming pool. If you’ve never seen this process we included a great video that showcases what it’s like.
Once gunite is applied to shape it will need time to set and cure to full psi strength. It takes a minimum of 24hrs for gunite to harden and up to 2 weeks to fully cure. It will be up to the homeowner to water the gunite 3 times each day for at least 1 week after gunite is applied.
7. Plumbing & Equipment
The total pool plumbing system or “long plumb” refers to the network of pipes carrying water to and from the swimming pool. It’s vital that your plumbing system be engineered correctly from the outset or pressure will be a problem.
A professional pool contractor has experience in engineering pool plumbing systems and will take into consideration distance, access, elevations, and pressure requirements to power water features. A typical pool & spa combination will feature a network of at least 12 pipes in the main trench.
8. Tile & Coping
The pool is nearing the final stages. At this juncture your pool contractor will bring in experienced tile installers to install tile and coping around the pool perimeter.
As we near the final stage your pool contractor will bring in decking installation experts. Popular choices these days are natural stone pavers such as flagstone or travertine. Your pool contractor will install a concrete substrate foundation and inset the stones with sand for added stability.
10. Plaster & Startup
Plaster applicators will arrive and pump the new plaster into the pool and hand trawl until a smooth surface has been achieved. After the plaster startup process is completed, filling up the swimmming may take up to 2 full days and nights. During this time your pool contractor will test the functionality of the installed components and perform the start-up process. This entire procedure can take over a week. At this point, the gunit pool is complete and ready to swim.
Why Gunite Pools Are Popular
Because of their durability and how versatile you can be with forming concrete, gunite pools offer outstanding customization and value.
There are millions of gunite pools in backyards around the country. Gunite remains the gold standard when it comes to pool construction and is the preferred material in high end backyards. They provide outstanding quality and offer an aesthetic of sophistication and luxury. For homeowners looking to transform their backyard into a resort style pool, there is no better choice than gunite.