How Long Can a Gunite Pool Stay Empty? Guidelines for Owners

You may have asked yourself if gunite pools can truly be left empty safely, or if it's a risk. It’s a smart question, and one every pool owner should know the answer to.

So, how long can a gunite pool stay empty? We'll walk you through that in this guide, plus discuss the risks that come with draining, and the guidelines you can trust to keep your investment safe.

Key Takeaways

• A gunite pool should not stay empty for long. Limit dry time to about two weeks to avoid structural risks.

• Hydrostatic pressure is the real danger because without water, soil and groundwater can push against the pool shell and cause it to crack or shift.

• Safe draining requires planning. Use hydrostatic relief, choose mild weather, and refill promptly to protect your investment.

Grounded Reality: Why This Matters

A gunite swimming pool is a carefully engineered structure that relies on balance. The pool water inside isn’t only for swimming but also helps counteract the hydrostatic pressure from the groundwater pushing against the pool walls.

Take that water away for too long, and an empty concrete pool can become vulnerable to shifting, cracking, or even lifting from its base.

In New England, where freezing weather, heavy rain, and unpredictable soil conditions are part of the landscape, the risk is even greater. A pool empty during a freeze-thaw cycle or an early spring storm could lead to structural strain and costly repairs. That’s why pool professionals recommend treating an empty pool as a short-term condition, not a long-term solution.

Expert Guidelines on Timing

Industry consensus is clear: an inground pool should never stay empty for long. For gunite pools, the best practice is to limit dry periods to no more than two weeks. Any longer, and you increase the real risk of shifting, cracking, or surface damage caused by groundwater pressure beneath the shell.

If your property has a high water table, even a few days can be enough to create stress. In these cases, a sump pump or hydrostatic relief valve may help, but if draining will last more than a week, get a second opinion from a pool professional. That guidance could prevent hidden issues, like floor cracks, surface blistering from heat or sunlight, or structural strain from freeze-thaw cycles.

The takeaway here is that draining should be a last resort, not routine maintenance. When it’s necessary (reset pool chemicals or remove stubborn stains), have a plan to properly drain, protect, and refill quickly so the pool isn’t left vulnerable for an extended period.

Risks of Extended Emptiness

Leaving a pool empty for too long is a structural gamble. Without the stabilizing force of pool water, the shell becomes vulnerable to hydrostatic uplift, where groundwater pressure can push upward, causing the pool to shift, crack, or lift from its foundation.

Even if the structure stays in place, the exposed surface of gunite is susceptible to damage. Heat, sunlight, and freeze-thaw cycles can cause plaster or pebble finishes to peel, flake, or weaken. As the water level drops, problems like algae growth or high total dissolved solids can also complicate a smooth refill.

Unlike vinyl liner pools, which rely on a liner that must stay filled to prevent shrinkage or wrinkles, gunite can handle short dry periods, but extended emptiness quickly increases the risk of costly repairs.

Treat draining as temporary and plan to restore water as soon as possible to prevent damage and keep your investment intact.

Safe Emptiness: Strategy Over Shortcut

Sometimes draining is unavoidable for repairs, deep cleaning, or balancing a tricky water chemistry issue. If your pool sits empty, a few careful steps can make all the difference.

• Pick the right time: Aim for dry, mild conditions. Avoid winter or rainy seasons when freeze-thaw damage or excess groundwater can put extra pressure on the shell.

• Relieve pressure: Use hydrostatic relief plugs to help equalize what’s happening beneath the pool floor, reducing the strain that can build when you drain your pool.

• Protect the surface: Cover exposed plaster to guard against UV rays and temperature swings that can dry out finishes and cause micro-cracks.

With the right precautions, you can handle necessary maintenance without causing damage to the structure itself.

Local Insight: Ferrari Pools’ Perspective

We at Ferrari Pools: Custom Outdoor Living have seen firsthand how important it is to treat draining as a carefully managed step, not an afterthought. Because we design and build with structural resilience in mind, our team understands the balance between form and function. Your pool has to be beautiful, but it also has to withstand the realities of New England weather.

When clients ask about whether to drain your pool, our guidance always comes back to timing, protection, and smart planning. Dry periods are kept short, surfaces are shielded from exposure, and drainage is handled with care to maintain the pool’s integrity.

Maintain the investment so it continues to bring joy season after season. With the right services and oversight, most pools can handle necessary downtime safely, without compromising their structure or style.

Let's Keep Your Pool Safe, Stylish, and Strong

Leaving a gunite pool empty for too long can create risks that most homeowners don’t expect—structural pressure, surface wear, and costly repairs. With the right timing, planning, and professional support, you can manage those moments of downtime without jeopardizing the investment you’ve made.

At Ferrari Pools, we design, build, and care for pools that are as resilient as they are elegant. And we don’t stop at pools. Our expertise extends to hot tubs, swim spas, patios, and custom outdoor living spaces that make your home feel like a retreat.

If you’re considering maintenance, planning a remodel, or simply want advice on caring for your pool, our team is here to help. Contact us today at (508) 366-5849 to schedule a consultation, and let us guide you in keeping your backyard a place of beauty, relaxation, and strength for every season.

Conclusion

A gunite pool is built to last, but it depends on water to stay in balance. When the pool is emptied, even briefly, it becomes more vulnerable to the pressures of soil, weather, and time. By keeping dry periods short and planning carefully, you protect the structure and preserve the surface and ensure the pool remains both strong and beautiful.

A drained pool should always be the exception, not the routine. With smart timing, proper safeguards, and professional guidance, your pool can move through necessary maintenance without losing its integrity or its elegance.

Frequently Asked Questions

How long can a swimming pool safely stay empty?

Most experts recommend limiting dry time to no more than two weeks. An empty swimming pool loses the stabilizing weight of water, which increases the risk of damage from shifting soil or pressure beneath the structure.

Are concrete pools more at risk when drained?

Yes. Concrete pools are designed to balance water pressure inside with the groundwater pressure outside. An empty concrete pool for an extended period is more likely to crack or shift compared to one that remains filled.

Why does hydrostatic pressure matter when a pool is empty?

Hydrostatic pressure is the upward force of water in the soil pressing against the bottom of an inground pool. Without the counterweight of pool water, this pressure can cause lifting, cracking, or other structural issues.

What is a hydrostatic relief valve, and how does it help?

A hydrostatic relief valve is installed at the base of many inground pools. When the pool is drained, it allows groundwater to pass into the pool, helping equalize pressure and reducing the risk of structural damage during maintenance.

What happens if an inground pool stays empty for an extended period?

If an inground pool is left empty for an extended period, it can develop surface cracks, structural shifting, or lifting due to soil and water pressure beneath the pool. These issues often lead to costly repairs that could have been avoided with proper precautions.