In-ground concrete swimming pools are usually durable installations that last for decades. However, gunite, shotcrete, or concrete walls may develop cracks over time. Small shrinkage cracks aren't a problem, but if the cracks grow large enough to insert a dime, the shell might be compromised.
Although rare, and affecting less than 1% of all pools, concrete pools can crack. If it happens at all, it usually happens within the first year, as a result of shrinkage, settlement and/or subsidence.
Small superficial cracks are called check cracks or crazing. This is normal due to the cement shrinking or flexing of the supporting structure, and should not be considered a deficiency. The most common cause for crazing is if the pool is finished on a hot, dry or windy day, or if it took too long to fill the pool.
A concrete pool that “floats” – or pops out of the ground – is an extremely rare event. Most of them occur during major flooding events or hurricanes.
Additionally, a lack of water means there's a lack of moisture on the pool walls. If left exposed to long periods under the hot sun, pool finishes will dry out, creating cracks and flaking.
Thankfully, the pool pop up rarely happens. In fact, it's an extremely rare occurrence, and it usually happens when there's a major flooding event or hurricane in the area, which saturates the ground and creates a super high water table.
Most concrete pools will last over 50 years as long as they are maintained. A concrete pool constructed by an expert should last a lifetime or more. Vinyl liner pools are far from ideal in this regard.
Concrete Curing
The shell will need to cure for around 30 days, during which time you will be asked to water it regularly to keep the outer layers of concrete cool to avoid cracking.
Pros and cons of concrete pools
Concrete pools are extremely durable and allow for a highly customized size and shape. The disadvantages include more effort to maintain, more chemical usage, highest cost of ownership, a rough interior surface, and a slow installation time.
Because everything moves with the changing of the seasons, it's important that the ground it's installed on has unified movement.
Structural cracks v.
Not all pool cracks mean that the pool is leaking, i.e shrinkage cracks are normal; they are shallow and just part of the curing process that occurs when the pool is first shot with gunite or shotcrete.
A cracked or chipped pool deck poses danger to pool owners and guests, as well as aesthetic problems. Besides a potential tripping hazard, cracks in the deck indicate, more importantly, there are more serious issues, such as ground shifting or a sink hole.
As we stated earlier, concrete comes ready mixed. With gunite, on the other hand, a dry mix is fired through a hose with the water being added at the point of delivery. Unlike concrete, when building gunite pools, you can stop and start without any problems, which will help give a smoother finish.
Special Care for Concrete Pools
Besides maintaining a constant balance of chemicals in your water, you will need to keep the concrete itself clean. The best way to do that is by simply brushing the walls. You can use a hard bristled brush attached to a telescopic pole to brush the walls and floor of your pool.
The first consideration to think of here is the material your pool is made from. Concrete pools generally need more effective pool heating systems, as concrete is a naturally cold material which is not particularly efficient at retaining heat.
Except the ultimate answer to whether a replacement vinyl liner can be installed in a concrete pool is anything but straightforward. Starting on the simple side of the equation, the answer is “yes” a vinyl pool liner can be installed in a concrete pool.
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.
How Long Will a Concrete Pool Last? A concrete pool should last decades (we're talking 50 years or more) if it is properly maintained. While the shell of the pool can become damaged if the building was not done correctly, a well-constructed concrete swimming pool should last a lifetime.
A popped or floating pool is a swimming pool that has risen out of the ground. Popped pools are not an everyday happening, but when they take place, they may result in irreversible damage to your pool.
Modern concrete pools can usually stand being drained for as long as needed, but there'll still be a risk of popping if the ground water level is high. Fibreglass pools are less resilient. The floor may come loose and float to the top when refilled, even after a short period.
Most inground fiberglass and concrete pools are built structurally to withstand the weight of the dirt against them when drained. However, if the groundwater is high enough, it can push the entire pool out of the ground. The pool shell acts like a ship and floats up in the groundwater.