Can a Gunite Pool be Left Empty? – Problems With Solutions

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When it comes to deciding whether a gunite pool can be left empty, the answer is not as straightforward as you may think. In some cases, it can be beneficial to leave your gunite pool empty while in other instances leaving the pool empty could cause serious damage.

The key is knowing when it’s safe and appropriate to leave a gunite pool empty, and when it’s better to keep water in the pool. The question “can a gunite pool be left empty?” is an important one that all pool owners should understand before making any decisions about their own gunite pool.

Key Takeaways

  • The decision to leave a gunite pool empty is not straightforward, and it requires understanding the risks and taking safety precautions.

  • Risks of leaving a gunite pool empty include structural damage, hydrostatic pressure issues, and shifting of the pool’s walls and floor.

  • If considering leaving a gunite pool empty, consulting a professional is highly recommended to ensure safety measures are in place.

  • If the pool needs to stay empty for an extended period, proper winterization is crucial, including draining, cleaning, repairing, and covering the pool.

  • Leaving a gunite pool empty for too long can lead to corrosion, plumbing and filtration damage, and increased algae growth.

  • Proper draining methods should be followed, and it’s best to consult a professional for guidance if uncertain about the process.

  • It’s never a good idea to leave a gunite pool empty for extended periods as it can lead to significant damage to the pool’s structure.

  • Regular maintenance and proper care are essential to ensure the longevity and functionality of a gunite pool.

Can a Gunite Pool be Left Empty

Before making the decision to leave your gunite pool empty, it’s important to understand the risks associated with emptying your pool. It is possible for a Gunite pool to be left empty but certain safety precautions need to be taken in order for this to happen safely.

This blog will provide an overview of the reasons why you may choose or not choose to leave your pool empty, and how to do so properly if you decide that it’s the right option for you. The goal is to provide an understanding of why and when it can be safe to leave a Gunite pool empty, helping all pool owners make informed decisions about the care of their own pools.

The Risks of Leaving a Gunite Pool Empty

When a gunite pool is left empty, it can cause serious problems that can be difficult and costly to fix. The main dangers include:

  • Risk of structural damage: Gunite pools are constructed with a mixture of concrete and sand, which is then sprayed onto a framework of rebar. This creates a strong and durable pool structure. However, the pressure exerted by the water inside the pool helps to reinforce and stabilize the gunite. When the pool is empty, there is no counterbalancing force, and the external pressure from the surrounding soil can cause the gunite to collapse or even pop out of the ground.

  • Hydrostatic pressure: Gunite pools typically have a hydrostatic relief valve installed in the main drain area. This valve allows water beneath the pool to drain into the pool itself, relieving hydrostatic pressure. If the pool doesn’t have a functioning hydrostatic valve or if it becomes blocked, leaving the pool empty can create a risk of the pool floating on top of the underground water. This can result in significant damage to the pool structure, including lifting or displacement.

  • Shifting and structural integrity: When a gunite pool is empty, it becomes susceptible to shifting and movement. The absence of water can lead to changes in the soil pressure around the pool, which can cause the pool’s walls, floor, and coping to crack or shift. These structural compromises can weaken the pool’s integrity and may require costly repairs.

If you are considering leaving a gunite pool empty for any length of time, it is highly recommended that you consult a professional before doing so to ensure that all safety measures have been taken. In most cases, it is much more cost-effective and safer to simply keep the pool filled with water.

How Long Can a Gunite Pool Stay Empty

When it comes to owning a gunite pool, it is important to know the answer to the question – can a gunite pool be left empty? The simple answer is yes, but there are some conditions that need to be met in order for this to happen.

If you want your gunite pool to stay empty for an extended period of time (more than a few months), then it is important to make sure that you winterize the pool before leaving it empty. This involves the following steps:

  • Drain all of the water.
  • Clean and remove any debris.
  • Check for leaks and cracks in the pool walls or flooring.
  • Repair any damage as needed.
  • Treat the surfaces with chemicals such as chlorine and algaecide.
  • Cover it up with a proper pool cover.

As long as you follow these steps, your gunite pool can be left empty for an extended period of time without any significant damage occurring. However, if the pool is not properly winterized before leaving it empty, then the walls and flooring could suffer from cracks, leaks, and algae growth due to the changing temperatures. In addition, if you leave your gunite pool empty for too long without winterizing it properly, then the structure can become weak and eventually collapse.

Why You Should Not Leave Your Pool Empty

Gunite pools are durable and long-lasting, so you may think that leaving your pool empty isn’t a big deal. But the truth is, it’s never a good idea to leave your gunite pool empty. Here’s why:

  • Structural Integrity: Gunite pools consist of a reinforced concrete shell sprayed with gunite or shotcrete. This creates a strong layer that supports water pressure inside the pool. However, when the pool is empty, the absence of water pressure can lead to cracks in the structure. These cracks weaken the pool and may even cause a full collapse.

  • Corrosion Risk: Leaving your gunite pool empty can result in the formation of corrosion on the metal re-bar used to reinforce the concrete shell. This corrosion weakens the pool’s structure and can lead to serious issues.

  • Plumbing and Filtration Damage: An empty pool can cause damage to the plumbing and filtration systems. Without water, the chemicals in the pool won’t be able to perform their intended functions, and the plumbing may be vulnerable to physical damage from external sources.

  • Increased Algae Growth: Another reason to avoid leaving your gunite pool empty is the potential for increased algae growth. Algae thrive in warm and damp environments, and a dry pool can provide such conditions. The additional algae growth can result in unsightly stains and can be a hassle to remove.

Leaving your gunite pool empty can lead to various structural, maintenance, and aesthetic issues. It’s essential to keep your pool properly maintained and filled with water to ensure its longevity and functionality.

How to Drain a Gunite Pool

If you’re looking to leave your gunite pool empty for a long period of time, it’s important to take the necessary steps for draining it correctly. Here’s a step-by-step guide:

  1. Turn off Pump and Filter: Before you begin draining the pool, make sure the pump and filter are both shut off.

  2. Direct Draining Method: You can choose to drain all the water from the pool directly into your sewer system using a sump pump. Follow these steps:

    • Locate the sewer line and attach it to your sump pump.
    • Start running the pump according to local regulations, usually at least once a day.
    • The draining process can take several hours to a few days, depending on the pool size and the amount of water.

  3. Pool Vacuum Method: Alternatively, you can use a pool vacuum to remove all the water. Here’s how:

    • Attach the pool vacuum to your filter pump.
    • Run both the vacuum and filter pump simultaneously.
    • The process may take several hours or a few days, depending on the pool size.

Remember, draining your gunite pool should only be done when absolutely necessary, as leaving it dry can cause damage over time. If you’re unable to refill the pool immediately, take preventive measures such as covering it with a tarp or using a dehumidifier to protect it from long-term damage.

If you’re uncertain about how to empty a pool or need guidance for leaving your gunite pool empty for an extended period, it’s advisable to consult a professional. They can assess the situation, discuss the pros and cons of draining, and ensure the procedure is carried out safely and correctly.


While it is not recommended to leave a gunite pool empty for extended periods of time, it is possible to do so in certain circumstances. If the pool has been properly maintained and all necessary precautions have been taken, then leaving a gunite pool empty for short periods can be done without any significant harm.

To ensure that your pool is safe and healthy, it is always best to consult with a professional and follow their advice. A properly maintained gunite pool can last for years with regular maintenance, so taking the necessary precautions now will ensure that your pool stays in good condition for many years to come.

Frequently Asked Questions (FAQs)

1. Can I completely drain my gunite pool?

Yes, you can completely drain a gunite pool. However, depending on the age of the pool and the type of plumbing, this process may cause damage to the interior finish or other components. It is recommended to consult with a professional before fully draining your gunite pool. Additionally, it is important to refill the pool in a timely manner to prevent further damage. If the pool is not refilled, the walls and floor may crack or shift due to ground movement. Also, potential problems related to the plumbing system could arise if the pool stays empty for too long. Therefore, it is important to carefully consider all risks before draining your gunite pool.

2. How long can you leave a gunite pool empty?

Generally, a gunite pool should not be left empty for more than two weeks. When the pool is left dry for extended periods of time, it can cause significant damage to both the gunite shell and the surrounding area due to cracks and shifting of the soil. It is also important to ensure that proper drainage systems are in place before leaving the pool empty for any length of time. In addition, all water should be removed from the plumbing, pumps and filters to prevent damage due to freezing.

3. Will an empty gunite pool crack?

No, an empty gunite pool should not crack. Gunite pools are designed to withstand shifting ground and extreme weather conditions without cracking or breaking down. However, if the soil underneath the pool is not properly compacted during installation, it may cause settling which could lead to cracks in the pool shell. To ensure a long-lasting result, it is important to hire a qualified pool contractor who can properly install the pool. Additionally, proper maintenance and regular inspections will help keep the gunite pool in good condition for years to come.

4. How long can pool plaster be exposed?

It is generally not recommended to leave pool plaster exposed for more than a week. Exposing the plaster for an extended period can be detrimental to its condition. It is advisable to refill the pool within a day or two after drainage to avoid long-term damage to the plaster. Leaving pool plaster exposed can cause issues such as cracking, peeling, loosening, or deterioration. The plaster can be susceptible to damage if it is not protected and maintained properly. It is important to ensure proper curing of the plaster to maintain its integrity.

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Written By Scott Keller

Scott Keller is an experienced pool industry professional with over 20 years of expertise in gunite pool design, construction, and maintenance.

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