How Long Can You Leave a Gunite Pool Empty?

It often starts with a maintenance project. A homeowner plans a repair, resurfacing job, or deep cleaning and realizes the gunite pool may need to be drained first. Once the water is gone, another question quickly comes up: How long can you leave a gunite pool empty?

A gunite pool is built with a strong concrete shell designed to last for decades. However, that structure is designed to hold water. When the pool sits empty for too long, outside conditions such as soil pressure, groundwater levels, and weather can sometimes create risks for the pool’s structure.

The good news is that in many situations, a pool can remain empty for a short time during maintenance or renovation work. Still, it’s important that the pool doesn’t stay empty longer than necessary.

In the sections ahead, we’ll look at how long you can leave a gunite pool empty, why draining a pool sometimes becomes necessary, and what factors determine how long it can safely remain empty.

Key Takeaways

• Gunite pools may need to be drained for repairs, cleaning, or resurfacing.

• Leaving a pool empty for too long can create structural risks depending on groundwater and soil conditions.

• Professional evaluation helps ensure draining and refilling are done safely.

  
  

Gunite Pools Sometimes Need to Be Drained

Most of the time, a swimming pool stays full year-round. However, there are certain situations where draining becomes necessary to perform maintenance or repairs. When this happens, a pool professional will typically evaluate the pool’s condition and ensure the pool is properly drained to protect the pool’s integrity.

Pool resurfacing

One of the most common reasons to drain the pool is resurfacing. Contractors need access to the entire pool floor and pool walls to remove the old finish and install a new surface.

Because resurfacing involves working directly on the interior structure of a concrete pool, the pool must remain empty during the project until the new finish is complete and ready to be refilled.

Major repairs

Certain repairs also require draining the pool. Structural fixes, plumbing repairs, or replacing damaged pool walls or tile may require the pool to be empty so technicians can inspect the structure and make the necessary adjustments.

If there are signs of structural issues, cracks, or leaks affecting the inground pool, draining allows professionals to examine the problem more closely and prevent further damage.

Deep cleaning or stain removal

Occasionally, an empty swimming pool is needed for deep cleaning. Severe staining, mineral buildup, or surface damage may require treatments that cannot be done underwater.

In these cases, draining allows technicians to remove stubborn buildup, treat the surface, and restore the appearance of the pool.

While draining is sometimes necessary, the amount of time the empty pool remains without pool water matters. Leaving an empty concrete pool for an extended period can introduce risks depending on groundwater levels, weather conditions, and the surrounding soil.

Leaving a Gunite Pool Empty Too Long Can Be Risky

While draining a pool is sometimes necessary for maintenance or repairs, leaving it empty for too long can create potential risks. A gunite pool is designed to hold water, and when that weight is removed, outside forces can affect the structure.

Groundwater pressure

One of the biggest concerns is groundwater pressure. When the pool is full, the weight of the water helps balance the pressure from the surrounding soil and underground water.

When the pool is empty, hydrostatic pressure from groundwater can build beneath the structure. In areas with a high water table or after heavy rain, rising groundwater can push upward against the pool shell. In rare cases, this can lead to shifting or serious structural damage.

Some pools include hydrostatic relief valves designed to release this pressure, but they must be monitored carefully when draining your pool.

Soil movement

Soil conditions can also affect an empty pool. As moisture levels change during rain, heat, or seasonal shifts like spring, fall, and winter, the surrounding ground can expand or contract.

Without the stabilizing weight of pool water, the pool structure may become more susceptible to soil movement, which can eventually lead to cracks or other structural issues.

Surface damage

Leaving a pool empty in hot weather can also affect the interior finish. Direct sunlight and heat can dry out the exposed surface, sometimes causing small cracks to develop.

During colder months, freezing weather can introduce freeze-thaw damage if moisture settles into small surface openings.

Because of these risks, pool professionals usually recommend limiting how long a pool remains empty and refilling it as soon as maintenance or repairs are complete.

How Long a Gunite Pool Can Safely Stay Empty

In most situations, a gunite pool can remain empty for a few days to about one week during maintenance or resurfacing work. This timeframe allows professionals to complete repairs while reducing the risk of structural problems.

Leaving a pool empty for more than two weeks is generally not recommended unless a pool professional is closely monitoring the situation. Extended periods without water can increase the chance of water pressure from surrounding soil or groundwater affecting the pool structure.

Factors that affect how long a pool can stay empty

Several conditions can influence how long a pool can safely remain empty:

• Groundwater levels: If the water level underground rises or drops quickly, it can affect pressure around the pool shell.

• Soil conditions and drainage: Proper drainage helps reduce the chance of water pressure building beneath the pool.

• Weather and temperature: Heavy rain, extreme heat, or seasonal changes can affect the surrounding ground.

• The pool’s condition: Older pools or those with existing cracks may require extra caution.

  
  

In some areas, professionals monitor hydrostatic relief systems designed to help control groundwater pressure when the pool is drained. Taking these precautions helps prevent damage and ensures the pool can be safely refilled once the work is finished.

Best Practices When Draining a Gunite Pool

Draining a gunite pool should always be done carefully to protect the structure and avoid unnecessary problems. A few simple precautions can help prevent damage and keep the pool in good condition.

Work with a pool professional

A qualified pool professional can evaluate groundwater levels, soil conditions, and the overall pool structure before draining begins. This helps identify potential risks and reduce the chance of costly repairs later.

Minimize empty time

In most cases, the pool should remain empty only as long as necessary for maintenance or repairs. Refilling the pool promptly helps maintain structural balance and protects the pool shell.

Monitor hydrostatic relief systems

Many gunite pools include hydrostatic relief valves designed to release groundwater pressure when the pool is empty. Monitoring these systems during draining helps protect the pool structure and ensures it can be safely filled again once the work is complete.

Renovate and Maintain Your Pool

Ferrari Pools: Custom Outdoor Living has spent decades building and renovating gunite pools for homeowners throughout the region. Our team understands the structural details that go into these pools, including how to safely drain and service them during resurfacing, repairs, and renovation projects.

When a pool needs to be drained, we carefully evaluate the surrounding conditions first. This includes reviewing soil stability, groundwater levels, and the overall structural integrity of the pool before work begins. Taking these steps helps protect the pool while maintenance or upgrades are underway.

If you're planning a repair, maintenance work, resurfacing project, or pool renovation and need guidance on safely draining your pool, our team is happy to help. Contact us to schedule a consultation, and we’ll help you explore the best options for maintaining and upgrading your pool.

Conclusion

A gunite pool can safely remain empty for a short time during repairs or maintenance, but it shouldn’t stay empty longer than necessary. With proper planning and professional guidance, draining and refilling the pool can be done safely while protecting the structure and the pool's long-term performance.

Frequently Asked Questions

How long can a gunite pool stay empty safely?

Most gunite pools can safely remain empty for a few days to about one week during maintenance or resurfacing. Leaving a pool empty longer should be done only with guidance from a pool professional.

Is it bad to leave a pool empty for too long?

Yes, leaving a pool empty for an extended period can create risks. Groundwater pressure, soil movement, and weather exposure can affect the pool structure and potentially lead to damage.

Can a gunite pool pop out of the ground?

In rare cases, yes. If groundwater pressure builds underneath an empty pool, especially in areas with a high water table, it can push upward on the pool shell and cause structural problems.

When should a pool be drained for maintenance?

Pools are typically drained for resurfacing, structural repairs, plumbing work, or deep cleaning that cannot be done underwater. A pool professional can determine when draining is necessary and how to do it safely.