Concrete pools can be made of either shotcrete or gunite. The difference is when the concrete mixes with the water. Shotcrete refers to wet concrete that's already fully mixed before it's shot out of a hose. Gunite is dry concrete mix that only mixes with water at the nozzle when it's sprayed.
Unlike concrete, when building gunite pools, you can stop and start without any problems, which will help give a smoother finish. With a skilled nozzleman, the mix of cement and water can be adjusted at the point of delivery as required, while it is also less prone to cracking than concrete.
Gunite tends to be less expensive than shotcrete, and it can result in fewer errors in the construction process.
But a properly built Gunite pool can and should last for 100 years or more, with no risk of cracking whatsoever. We've been building Gunite pools for more than 40 years (more than 4000 swimming pools), and we've never had one crack yet.
Gunite swimming pools are highly durable and can be created in just about any shape. They don't require wooden frameworks to hold the shape of the pool basin. Custom Gunite pools have become very popular lately, and it's easy to see why.
Ready-made gunite pool projects typically cost between $50,000 and $100,000 upfront. In addition to this significant upfront cost, concrete pool maintenance costs over $25,000 every ten years thanks to regular acid washes, replastering, and high chemical and electricity usage.
If you're looking for a simple answer, the answer is yes. Saltwater chlorinators are perfectly safe for gunite pools. The biggest issues reported when using saltwater chlorinators with gunite pools have to do with the tendency of the plaster to stain over time when coming into contact with salt.
On average, gunite swimming pools last 7 to 10 years before they need to be resurfaced. When that time comes, it's important to know what options are available so that you can pick the best choice for your backyard space.
The “shell” of your swimming pool can be made of almost any durable material, but two particularly popular choices stand out: gunite and shotcrete. Both are forms of concrete, but their formation and consequently expected lifespan differ enough to give any homeowner pause.
Gunite and shortcrete are essentially the same material, but they are applied with different processes. Gunite is the popular trade term for dry-gun concrete, while shotcrete is the common term for wet-gun concrete.
Generally, the pool walls need to be between three and four inches thick. Smooth the pool walls with your trowel, as you did for the base. Now the concrete has to cure properly before you can fill it with water. The concrete curing process allows the concrete to reach maximum strength and takes approximately 28 days.
Gunite is a dry-gun concrete and shotcrete is a wet-gun concrete. For gunite, dry concrete is put into the hopper and forced out of a hose, through a nozzle.
On Average, Replastering is Every 10 Years
So how often do you need to replaster a pool? The short answer is about every 10 years. However, it's important to consider the factors mentioned above, as they are typical signs that your pool needs to be replastered.
In a nutshell, replastering a pool means putting a new layer of plaster on the walls and bottom. What does plaster do? First, it serves to make your pool waterproof. Kind of important, right? When you had your pool installed, the people who did it likely used either concrete or gunite to form the “shell” of the pool.
Cleaning Stains
If you have white crystals forming on the plaster, you probably you have calcium deposits. If you have gray or dark colored stains, then fiberglass or iron particles may be the culprit. Copper may be causing bluish-green stains, while manganese typically creates pink or red patches.
Tile Finishes
Though tile is the most expensive pool finish and takes longer to install than plaster and aggregate, it's the longest lasting pool surface. With proper application and minimal maintenance, tiles should never need to be replaced. Tile pool finishes come in ceramic, porcelain, glass and stone.
Pros of Saltwater Pools
There's less chlorine and less of the heavy chemical scent and content. They're gentler on the skin, with less irritation to the eyes, hair and swimsuits. The water has a softer, silkier feel to it compared to chlorine water. They have lower maintenance costs than chlorine pools.
Gunite pools are incredibly durable and do not require a liner. This allows the pool to look better and retain its shape over time. One of the main disadvantages of a gunite pool is the time it takes to install the pool from start to finish.
Concrete Pools
Concrete, or gunite, pools don't need a liner either. But concrete is a very porous material and will readily allow the growth of algae unless the water is properly maintained. You'll use far more chemicals with concrete pools than you would with vinyl or fibreglass models.
It is very easy to change your existing pool into a Concrete/Gunite Pool. With this option you can shallow or deepen the pool. From there you can retain the shape that you currently have using the existing walls to shoot up against.
A fiberglass pool is not prone to growing algae, which is one of the main reasons why this pool is easier to maintain. Anyone who is looking for a pool that doesn't require a lot of maintenance may want to consider going with a fiberglass pool.
One of the most important steps in gunite or concrete swimming pool construction is selecting the right type of waterproofing. Concrete is a porous substrate prone to water penetration; therefore, it has to be sealed to keep water in the pool, in addition to keeping ground water out, which is often forgotten.