Keeping an inground pool empty is a topic that raises both practical and technical concerns for pool owners. Whether you’re preparing for a long vacation, planning to winterize your pool, or facing unexpected drainage issues, understanding the implications of leaving a pool empty is crucial. This comprehensive guide delves into the feasibility of keeping an inground pool empty, the different types of inground pools and how they respond to being empty, potential risks, and best practices to follow.
Understanding Inground Pool Basics
Before we address the question of whether you can keep an inground pool empty, it’s important to understand what makes inground pools unique. Unlike above-ground pools, which are more portable and often built with flexible walls, inground pools are fixed installations made with durable materials designed to withstand constant exposure to water.
Types of Inground Pools
Inground pools come in various types, each with specific characteristics that influence how they handle being empty:
- Concrete Pools – Also known as gunite or shotcrete pools, these are the most durable. However, their plaster finish is vulnerable to cracking if the pool is left empty.
- Vinyl Liner Pools – These feature a flexible vinyl barrier. If left empty, especially in direct sunlight, the liner can shrink, distort, or tear.
- Fiberglass Pools – Pre-molded and installed as a single shell, fiberglass pools are generally more resistant to damage when empty but still need protection against structural stress.
Can You Keep an Inground Pool Empty? The Short Answer
For many homeowners and property caretakers, the short answer is yes, you can keep an inground pool empty temporarily, but there are critical considerations to be aware of. The longer a pool remains empty, the greater the risk of damage. The duration depends on the pool type, local climate, ground conditions, and whether water or counterweights are used to stabilize the structure.
Temporary vs. Permanent Drainage
The difference between temporary and permanent pool drainage determines the level of care required:
Temporary Drainage (Up to a Few Weeks)
For short periods such as routine maintenance, repairs, or when cleaning the pool, emptying the pool is acceptable, provided certain precautions are followed.
Permanent Drainage (Several Months or Indefinitely)
Leaving an inground pool completely empty for months or years is rarely recommended unless it’s being decommissioned. Permanent drainage without proper measures can lead to irreversible damage, structural issues, and costly repairs.
Reasons to Empty an Inground Pool
There are several reasons that may lead homeowners to drain their inground pool. Each comes with specific risks and considerations.
Repair and Renovation
If your pool requires significant repairs—such as fixing cracks, replacing tiles, repairing the plumbing system, or resurfacing—it’s often necessary to drain the pool. The absence of water allows for thorough inspection and treatment of the affected areas.
Winterization in Colder Climates
In regions where freezing temperatures are common, pool owners may partially or completely drain pools to prepare for winter. This helps prevent damage from frozen water expanding in pipes and components. However, pools aren’t usually left entirely empty; instead, water levels are lowered to accommodate winter covers and protect equipment.
Chemical Imbalances or Contamination
Sometimes, pools become contaminated due to algal blooms, chemical imbalances, or other water quality issues that are impossible to correct through partial draining and chemical treatment. In these cases, completely draining and refilling the pool may be necessary.
Structural Issues or Repositioning
If construction or landscaping necessitates the relocation of the pool, or if significant structural issues arise, draining the pool becomes a step in the process.
Risks of Keeping an Inground Pool Empty
While draining an inground pool is sometimes unavoidable, understanding the risks that come with this action helps in making informed decisions.
Structural Damage
One of the most significant risks is structural damage caused by hydrostatic pressure and environmental elements.
Hydrostatic Pressure Risks
When an inground pool is empty, there is no water pressure inside to counteract the pressure from groundwater outside the pool structure. This imbalance can lead to:
- Hydrostatic uplift – where the pressure from underground water lifts the pool from its foundation.
- Cracking in concrete pools due to force from surrounding soil and groundwater.
- Deformation of fiberglass or vinyl pools if not anchored properly during drainage.
To mitigate this, professionals often recommend leaving water in the pool or placing weights (like sand bags) evenly throughout the empty pool.
Damage to Surfaces and Liners
Different pool materials react uniquely to being dry for extended periods.
- Concrete and plaster pools can dry out and crack, especially in hot, sunny climates.
- Vinyl liners may shrink, warp, or become brittle if exposed to too much sun or heat without moisture.
- Fiberglass pools are less likely to crack but can suffer from surface damage without water support.
Safety Hazards and Liability
An empty pool poses potential safety hazards, particularly to pets and small children. An exposed, empty structure may be seen as an open, accessible area, which increases the risk of falls, injuries, or more serious incidents.
Moreover, in many jurisdictions, having an empty pool that is not properly secured or covered can result in legal liability for any accidents that occur on the premises.
Best Practices for Leaving an Inground Pool Empty
If leaving your inground pool empty is necessary, certain steps can be taken to ensure safety and reduce the risk of structural damage.
Check Groundwater Conditions
Before emptying a pool, it’s important to assess the water table in the area. If the groundwater level is high, special precautions such as hydrostatic relief valves or temporary water levels must be considered.
Keep the Pool Properly Balanced
Use Weights or Water to Offset Pressure
In many cases, maintaining a small water level or using sandbags can help maintain an equilibrium between internal and external pressure.
Install Hydrostatic Relief Valves
Some inground pools are equipped with hydrostatic relief valves designed to release pressure from groundwater when the pool is drained. If your pool does not have one, consult a pool professional to determine if one should be installed.
Ensure Proper Covering and Protection
To prevent debris, sunlight, or moisture damage:
- Use a durable pool cover to keep the basin protected.
- Install temporary fencing to improve site security.
- Store equipment and filters indoors if the pool is being drained for an extended duration.
Maintenance During Drained Periods
Even an empty pool still needs some level of maintenance if left unattended:
- Check regularly for signs of shifting or cracking.
- Drain any rainwater that accumulates in the pool basin if safe to do so.
- Monitor the weather forecast and environmental conditions.
How Long Can You Safely Leave an Inground Pool Empty?
The safe duration for keeping an inground pool empty varies based on several factors:
Concrete Pools
Leaving a concrete pool empty for more than a week can cause the plaster surface to lose moisture, leading to shrinkage and cracking. If kept dry for a month or more, significant structural deterioration may begin to occur.
Vinyl Liner Pools
Vinyl liners should not be left dry for more than a few weeks without protection. Prolonged dryness and sun exposure can cause permanent damage.
Fiberglass Pools
These are more durable than vinyl and are less susceptible to cracking. However, keeping them empty for a few months without proper safeguards can stress the structural shell, especially if there’s an imbalance in groundwater pressure.
Why Consulting a Pool Professional Matters
While many pool owners might attempt DIY solutions, keeping a pool empty safely often requires expert guidance. A professional pool contractor can:
- Evaluate your pool’s structural integrity.
- Advise on groundwater conditions and risk mitigation.
- Recommend the most suitable period for draining based on your region and pool type.
Alternatives to Completely Draining Your Pool
If your intention for emptying the pool doesn’t require full draining, consider the following options:
Partial Drainage
Certain maintenance tasks, such as tile cleaning or painting, don’t require complete emptying. Use a submersible pump to lower water levels as needed.
Refill as Soon as Possible
If you’ve drained your pool for maintenance, refill as soon as possible to restore internal pressure and help avoid issues.
Use Pool Covers and Surface Protectors
To preserve the surface of an empty pool, especially concrete or fiberglass ones, consider applying sealants or using temporary coatings that protect the finish from UV rays and heat damage.
Key Takeaways on Keeping an Inground Pool Empty
To sum up, here are the essential points every pool owner should understand about keeping their inground pool empty:
- Yes, most inground pools can be safely emptied temporarily, but the duration should be limited.
- Hydrostatic pressure and groundwater present major structural risks if not properly managed.
- Plaster finishes, vinyl liners, and fiberglass surfaces are all vulnerable to damage when left dry for too long.
- Use counterweights or maintain partial water levels to offset external pressure.
- Consult a professional before emptying your pool for extended periods.
- Prioritize safety by covering the pool and securing the area if it’s left empty for a prolonged period.
Conclusion
In conclusion, while it is technically possible to keep an inground pool empty for short periods, doing so for an extended duration poses significant risks to the structural integrity and longevity of the pool. Whether concrete, vinyl, or fiberglass, each type of pool requires specific care when being emptied. Proper evaluation of groundwater conditions, the use of hydrostatic relief measures, and regular monitoring can help mitigate potential damage.
By following best practices, consulting professionals, and being aware of alternative options, you can safely manage your inground pool during periods of maintenance or seasonal changes without compromising its condition. Understanding how to properly drain and protect your pool ensures it remains a safe, clean, and enjoyable feature of your outdoor space for years to come.
Keep these guidelines in mind, and remember that the health of your pool doesn’t stop when the water does. Safe and informed maintenance practices are the key to preserving your investment in the long run.
Can you keep an inground pool empty for an extended period?
Keeping an inground pool empty for a long time is generally not recommended and can lead to serious structural issues. Pools are designed to hold water, and without it, the empty shell can become vulnerable to damage from hydrostatic pressure, ground movement, or freezing temperatures. In areas with high groundwater levels, the pressure from beneath the pool can cause it to shift or even pop out of the ground, leading to major structural damage that can be expensive to repair.
While short-term emptying for maintenance or repairs is acceptable, leaving the pool empty for months or years requires careful planning. If you must leave it empty for an extended period, it’s important to ensure the pool is completely drained according to local guidelines, the water table in your area is low, and measures are taken to prevent water from accumulating around or beneath the structure. Consulting a professional pool contractor before draining the pool is always a wise choice.
Why would someone choose to keep their inground pool empty?
There are a few reasons why a pool owner might consider keeping their inground pool empty. Some may do it temporarily to perform repairs or resurfacing work, which typically requires the pool to be drained. Others might choose to keep it empty when preparing for winterization in colder climates, though this is rare and must be done carefully. In some cases, homeowners might decide to stop using the pool due to lifestyle changes, cost of maintenance, or backyard renovations, and opt to leave it empty until a final decision is made regarding removal or repair.
However, even in these scenarios, keeping an inground pool empty should be a temporary measure. Prolonged emptiness can expose the pool to environmental damage and reduce its lifespan. For long-term disuse, the best practices usually involve partial filling, the use of protective covers, or considering pool closure or removal solutions rather than leaving a pool exposed and unused for months or years.
What are the risks of keeping an inground pool empty?
Leaving an inground pool empty exposes it to several risks, starting with hydrostatic pressure. If the water table in your area rises, pressure from groundwater beneath the pool can cause it to lift or crack, especially with concrete or fiberglass pools. This kind of damage can be extensive and expensive to repair. Additionally, an empty pool shell is more prone to shifting or cracking due to soil pressure and movement, particularly after heavy rain or freeze-thaw cycles.
Another major concern is the deterioration of interior surfaces such as plaster or tiles. These materials can dry out and become brittle over time, leading to cracks, scaling, or peeling. An empty pool also becomes a safety hazard, especially for families with children or pets, as there’s a risk of falls or entrapment. Finally, leaving a pool unused and exposed can attract debris, pests, and algae growth if rainwater accumulates inside, creating unsightly and unsanitary conditions.
How long can you safely keep an inground pool empty?
The safe timeframe for keeping an inground pool empty largely depends on the type of pool and the local environment. In general, most pools can remain empty for a few weeks without serious issues, especially if preparatory steps are taken to protect the structure. Concrete pools are particularly vulnerable to groundwater pressure and should never be left empty in areas with a high water table. Fiber-glass and vinyl pools also face risks due to their susceptibility to shifting or bowing if left drained without proper countermeasures.
To determine how long your pool can stay safely empty, consult a licensed pool professional or contractor familiar with local conditions. If the pool must be kept empty for more than a month, it may require special hydrostatic relief valves, weight distribution, or even water reintroduction at intervals to maintain structural stability. In some cases, environmental factors like heavy rainfall or fluctuating temperatures can force unexpected maintenance, so monitoring the pool closely during this time is crucial.
What should you do before draining an inground pool?
Before draining an inground pool, it’s crucial to understand the structural and environmental factors at play. Consider the type of pool you have—vinyl, concrete, or fiberglass—as each has different risks when drained. Concrete pools are heavy and more resistant to floating but can crack from ground pressure. Vinyl pools may bulge or collapse if water pressure isn’t balanced. Fiberglass pools are especially prone to lifting or warping. Check local building codes or restrictions on draining pools, as some areas require permits or professional oversight.
Also, evaluate the groundwater level in your area, especially during rainy seasons or periods of high moisture. If groundwater is high, consider installing a dewatering system or keeping a small amount of water in the pool. Ensure the pool’s plumbing and filtration system are properly winterized or disconnected to prevent damage from freezing or backflow issues. If you’re unsure about any of these factors, consult a qualified pool technician who can assess your situation and provide guidance on safe draining and maintenance procedures.
Can you keep a portion of water in the pool instead of fully draining it?
Yes, leaving a portion of water in the pool can be a safer alternative to keeping it completely empty. This approach helps maintain the balance between the pool structure and surrounding groundwater pressure, reducing the risk of the pool popping out of the ground. Typically, pool professionals recommend maintaining at least a few feet of water in the pool to help stabilize it, especially during periods of excessive rain or fluctuating water tables.
Partially filled pools also retain more structural integrity than completely empty ones. This method allows pool owners to perform necessary maintenance or inspections without fully exposing the shell to damage. However, it’s still important to cover the pool securely, protect any exposed surfaces, and monitor water levels and soil conditions regularly. This method should not be considered a permanent solution but a practical intermediate step when a full shutdown or renovation is being planned.
What are the best practices for maintaining an empty inground pool?
If you must keep your inground pool empty for a period of time, there are several best practices to minimize damage and prolong its condition. First, ensure that the pool is completely drained following professional guidelines and that any hydrostatic pressure underneath the pool is properly managed. Install hydrostatic relief valves if needed, and consider backfilling with gravel or installing support structures if the pool will be exposed for a long time.
Second, protect the surfaces from weathering, UV exposure, and debris. Cover the pool with a durable, secure tarp or decking to prevent water from collecting inside and reduce risk of accidents. Regular inspections are necessary to assess for cracks, warping, or environmental damage. Additionally, maintain the surrounding area by ensuring proper drainage away from the pool to prevent ground saturation. These precautions will help maintain the integrity of your pool and make it easier to recommission or safely remove later.