Installing an above ground pool is a great way to enjoy cool summer days without the high cost and complexity of an in-ground installation. However, before filling the pool with water, many homeowners face a key question: Do you have to put sand under an above ground pool? This question is rooted in the desire to protect the pool’s structure, ensure even weight distribution, and prolong the life of the pool liner.
In this comprehensive guide, we explore the ins and outs of using sand under an above ground pool, covering the benefits, alternatives, how-to steps, and common misconceptions. Whether you’re a first-time pool owner or looking to improve your existing setup, this article is your go-to resource.
Why Sand is Commonly Used Under Above Ground Pools
Sand has long been a go-to material for preparing the base of above ground pools, and for good reason. Let’s break down why it’s a popular choice:
1. Protection Against Sharp Objects
One of the primary functions of sand is to act as a cushioning layer, protecting your pool liner from sharp objects like rocks, roots, or debris in the soil beneath. The sand effectively redistributes pressure and reduces the risk of punctures and abrasions that could lead to leaks.
2. Provides an Even Surface
Sand is easily leveled and compacted, creating a smooth and even base. This is crucial for maintaining the structural integrity of the pool and ensuring the liner sits correctly without wrinkles or folds that might cause stress or tearing over time.
3. Drainage and Moisture Management
Sand has a moderate level of permeability, meaning it allows for some water drainage while still providing a stable surface. This helps prevent water accumulation directly beneath the pool, which can lead to mold or mildew problems and potential damage to the surrounding structure.
4. Availability and Affordability
Compared to other materials like concrete or foam padding, sand is relatively inexpensive and widely available. This makes it an accessible option for homeowners on a budget.
Types of Sand for Pool Bases
Not all sand is created equal, and choosing the right type can make a big difference in the performance and longevity of your pool base.
1. Mason or Concrete Sand
Mason sand is finely ground and typically composed of crushed stone or quartz. It packs well and creates a firm, smooth surface, making it ideal for leveling underneath a pool.
2. Play Sand
While play sand is soft and safe for children, it may not be the best option for a pool base. It tends to have more dust and fine particles, which can settle unevenly and lead to a less stable foundation.
3. Stone Dust
Stone dust, or quarry dust, is usually cheaper and compacts well. However, it can retain water, leading to potential moisture-related issues. It’s not recommended unless mixed or used under specific conditions.
Alternatives to Sand: What Are Your Options?
Sand is common, but not the only viable base material for above ground pools. Let’s compare some alternatives and understand when they might be a better choice.
1. Foam Padding
Foam underlayment, often made of closed-cell polyethylene, is designed specifically for use under above ground pools. It provides cushioning and can conform to slightly uneven surfaces, and it is excellent at protecting the liner.
Pros
- Superior cushioning compared to sand
- Lightweight and easy to install
- Doesn’t wash away or erode
Cons
- More expensive than sand
- Not effective on very uneven surfaces
2. Tarp and Level Ground
Some people opt for placing a heavy-duty tarp directly over a well-leveled and cleared ground, skipping the sand or foam entirely.
Pros
- Quick and easy
- No material cost beyond the tarp
Cons
- Suitable only for very smooth, ideal ground conditions
- High risk of liner damage if ground is uneven or contains debris
3. Concrete or Paver Base
A concrete or paver surface is sturdy and long-lasting, ideal for permanent installations.
Pros
- Extremely durable and stable
- No maintenance or shifting after installation
Cons
- Costly and time-consuming
- Not easily reversible if pool needs to be moved
4. Landscaping Fabric and Gravel
A combination of landscaping fabric and gravel can be used to create a stable, breathable base that also deters weeds and provides good drainage.
Pros
- Good drainage properties
- Prevents weed growth and pest infestation
Cons
- Requires more preparation and effort
- Not as smooth as sand or foam for liner protection
Do You Really Need Sand Under an Above Ground Pool?
So, what’s the answer? While it’s not absolutely mandatory, using sand beneath an above ground pool is highly recommended due to the many advantages it offers in terms of protection, stability, and cost.
However, the necessity of sand ultimately depends on several factors:
1. Condition of the Ground
If your backyard is rock-solid, level, and completely free of debris, you may get away without using sand. However, most natural surfaces have some irregularities that could damage the pool liner over time.
2. Type of Pool
Pools with metal or resin walls can tolerate slightly uneven surfaces better than inflatable or soft-sided pools, which are more prone to stress and tearing.
3. Climate and Weather Conditions
In regions with heavy rain or freeze-thaw cycles, sand can provide better stability and drainage, reducing the risk of shifting or water accumulation beneath the pool.
4. Longevity and Use
If you plan to use your pool seasonally and move it every few years, sand is ideal because it can be easily removed and replaced. For long-term installations, consider combining sand with foam padding or exploring more permanent base options.
How to Install Sand Under an Above Ground Pool: Step-by-Step
If you’ve decided to use sand under your pool, it’s important to do it correctly. Here’s a step-by-step guide to help you prepare the base:
1. Choose the Right Location
Look for a flat, level area that’s away from large trees, slopes, or areas with poor drainage. Avoid spots with underground utility lines or structures.
2. Clear the Area
Remove grass, weeds, rocks, tree roots, and any other debris. Use a shovel and rake to clear the top layer of soil. Aim for a depth of about 4 inches if you plan to lay sand.
3. Level the Soil
Use a hand tamper or plate compactor to press down the soil and create a stable foundation. Apply a layer of gravel (if desired) beneath the sand for enhanced drainage.
4. Install Landscaping Fabric (Optional)
Place a layer of landscaping fabric over the soil to prevent weeds and discourage pests. This also helps maintain soil integrity.
5. Spread the Sand
Pour the sand in even layers, smoothing each layer with a rake. Aim for a thickness of 2 to 4 inches. Too much sand can hold moisture and cause shifting, while too little might not offer enough cushioning.
6. Compact and Level the Sand
Walk over the sand or use a tamper to press it down firmly. The goal is to create a solid and even surface with no dips or high spots.
7. Add Pool Liner and Foam Underlayment (Optional)
Before placing the pool, consider adding a foam underlayment for extra protection. This can prevent sand from working its way through small pinholes in the liner over time.
8. Place and Fill the Pool
Once the sand is level and firm, follow the manufacturer’s instructions to install your above ground pool. Fill slowly and continue monitoring the base for shifts as the weight of the water settles the structure.
Common Mistakes to Avoid When Installing Sand Under Pools
To ensure the best results and extend the life of your pool, be sure to avoid these common pitfalls:
1. Using Wet or Moist Sand
Always use dry sand to prevent molding and uneven settling. Wet sand can clump or harden, creating dips and unstable areas under the pool.
2. Skipping the Tamping Step
Failure to compact the sand can lead to shifting and settling over time, causing wrinkles in the liner and even structural issues.
3. Choosing the Wrong Sand Type
Avoid using play sand, crushed concrete, or very fine sand that does not pack well. Opt for screened sand with consistent granule size for optimal results.
4. Laying Sand Too Thick
More sand isn’t always better. Exceeding 4 inches can hold water and reduce stability. A thin, level, and compacted layer is more effective.
5. Ignoring Future Drainage Issues
Ensure that your pool’s base allows for proper drainage away from the pool. Standing water beneath can promote mold growth and damage the liner.
Expert Tips for a Long-Lasting Pool Base
Want your pool to last many seasons? Consider these professional tips when preparing your sand base:
1. Combine Sand and Foam
Many pool professionals recommend using both sand and foam underlayment for the ultimate protection. The sand offers stability, while the foam prevents abrasive contact between the grains and the liner.
2. Use a String Level to Ensure Precision
Set up string lines around the perimeter of the pool base and check the level at multiple points. It’s more accurate than judging by eye, especially for larger pools.
3. Consider Using a Base Kit
Some pool brands offer base kits that include sand, foam padding, and leveling tools. These can save time and ensure a proper setup, especially for beginners.
4. Re-Level Between Seasons
Over the winter or during heavy rains, the sand base may settle or shift. Inspect and re-level your pool before starting up again each season.
5. Invest in Quality Materials
While saving money is always tempting, low-quality sand that contains dust or debris can hurt your pool’s performance in the long run. Spend a little more upfront to avoid liner problems later.
Environmental and Climate Considerations
The effectiveness of sand as a base material can also be influenced by regional climate and environmental conditions. Understanding your local environment is key to ensuring a durable setup.
Areas with High Rainfall
In regions with frequent rain, be cautious when using sand. While sand drains better than clay, standing water can still collect if the surrounding ground doesn’t slope away from the pool. Proper grading and drainage are essential.
Hot, Dry Climates
In arid areas, sand remains dry and stable for long periods, making it an excellent base option. Just beware of sand erosion from wind or frequent pool movement.
Freeze-Thaw Zones
In northern climates that experience frost, moisture in the sand can expand and contract during winter, leading to shifting. Consider draining your pool and covering the base with a tarp during off-seasons.
Can You Use Sand Under Inflatable or Soft-Sided Pools?
Inflatable and soft-sided pools are especially sensitive to sharp objects and uneven ground. Using sand beneath them is even more important since their liners are thinner and more prone to punctures.
However, always make sure the sand is smooth and packed tightly to prevent shifting under the flexible structure of these pools.
Final Thoughts: Is Sand a Must? The Verdict
In conclusion, while it’s technically possible to install an above ground pool without sand, doing so poses unnecessary risks, especially for the liner. Sand is a low-cost, effective way to protect your investment and ensure a longer pool life.
To recap:
Use sand if:
- You want to protect the pool liner from sharp objects
- Your ground isn’t perfectly level or smooth
- You’re in a region with variable climate
Skip sand if:
- You’re placing the pool on a prepared concrete or tarp surface
- Your ground is already perfectly flat and free of debris
Regardless of the base you choose, always prioritize proper leveling, drainage, and liner protection to ensure the best results.
By taking the time to prepare the base correctly, you’ll enjoy a safer, more stable, and more comfortable pool experience all season long.
So, do you have to put sand under an above ground pool? While the answer isn’t strictly “yes”, choosing sand is typically the smartest, most balanced option for the majority of pool setups.
Why is sand recommended under an above ground pool?
Sand is commonly recommended as a base material for above ground pools because it provides a smooth, level surface that helps protect the pool liner from punctures and uneven pressure. It acts as a cushion, distributing the weight of the water evenly across the bottom of the pool, which can prevent wrinkles and stress in the liner. Additionally, sand helps to stabilize the pool structure and reduces the risk of shifting or settling over time.
Sand also has excellent drainage properties, which is crucial for preventing water accumulation beneath the pool that could lead to mold, algae, or damage to the flooring. Because sand compacts well and is easy to grade, it allows homeowners to achieve a more even foundation, which is essential for ensuring the safety and longevity of the pool. When properly installed, a sand base contributes to a more comfortable and durable installation.
Can I use materials other than sand under my above ground pool?
Yes, there are alternatives to using sand under an above ground pool, including solid foam padding, concrete, patio blocks, or specialized pool floor kits. These materials can also provide a protective and stable base while offering additional benefits such as added cushioning, easier cleanup, or a more finished look. The choice of material often depends on the specific pool model, local climate, and personal preferences.
However, each alternative has its own set of advantages and limitations. For example, concrete offers a very stable base but can be expensive and requires proper drainage to avoid water pooling underneath. Solid foam padding can provide comfort but may not be recommended for larger pools due to the risk of compression over time. It’s important to consult the manufacturer’s guidelines and consider the site conditions when selecting the base material for your pool.
What type of sand is best for under an above ground pool?
The best type of sand to use under an above ground pool is fine, clean masonry sand or play sand, as these materials are smooth, free of rocks and debris, and compact well. Avoid using coarse sand or sand with high clay or silt content, as these can clump or shift over time, leading to an uneven base that may damage the pool liner. It’s important to use sand that is inert and non-reactive to water exposure.
Before spreading the sand, it’s a good idea to sift or screen it to remove any large particles that could scratch or puncture the liner. Typically, a layer of 1 to 2 inches of sand is sufficient, depending on the condition of the ground below. This thin layer provides enough cushion without becoming too loose or creating instability. Be sure to level the sand thoroughly to maintain a flat, even surface.
How do I prepare the base before putting sand down?
Prior to placing sand under your above ground pool, it’s crucial to properly prepare the ground beneath. Begin by clearing the area of grass, rocks, roots, and any other debris that could interfere with the foundation. Once the soil is exposed, assess the grade and make necessary adjustments to ensure a flat, level surface. Minor depressions should be filled and compacted to avoid future settling issues.
After cleaning and leveling the ground, you may want to use a layer of landscaping fabric for additional protection. This can help prevent weed growth and deter insects from burrowing up into the sand. Once the fabric is in place, you can begin spreading the sand evenly across the site, using a screed or straight board to keep the surface smooth and uniform. Compact the sand using a hand tamper or lightly moisten it to promote settling.
Is sand necessary for all types of above ground pools?
Sand is not always required for all above ground pools, especially those designed to be installed on decks, patios, or pre-leveled concrete surfaces. Some above ground pool models come with reinforced bases or grates that allow for installation without a sand pad. However, even in these cases, a protective layer like foam can be beneficial to cushion the floor and reduce wear over time.
It’s important to check with the pool manufacturer or installation instructions before deciding against sand. While certain pools can handle harder surfaces without additional padding, others might be at greater risk of damage or leaks without it. Always consider the unique requirements of your pool type and location to determine whether sand—or another type of base material—is necessary for safe and effective installation.
Can I use dirt or grass as the base instead of sand?
It is generally not recommended to use bare dirt or grass as the base for an above ground pool without some form of protective layer such as sand or padding. Grass can die and decompose under the weight of the filled pool, leading to an uneven surface and possible mold issues. Dirt, especially loose or loamy soil, can shift, erode, or compress unevenly, leading to structural stress and liner damage.
Even on a flat, dirt surface, sharp roots, rocks, or insects can cause long-term damage. If the ground is hard-packed clay and the area is level, it may support a small pool temporarily, but this is risky. For safety and stability, using a protective base like sand or foam padding is always advisable. It helps preserve the integrity of the liner, offers better comfort, and contributes to a more durable setup.
How much sand do I need for my above ground pool?
The amount of sand you’ll need depends on the size of your above ground pool and the condition of the ground beneath. A recommended 1 to 2 inches of sand spread evenly over the base area usually provides an ideal balance between support and protection. To calculate how much sand you need, multiply the radius squared by pi (for round pools) or length times width (for oval or rectangular pools) and multiply that by the sand depth in feet (1 to 2 inches = 0.083 to 0.166 feet).
For example, a 24-foot round pool would cover an area of about 452 square feet. At 2 inches deep, you’ll need roughly 452 * 0.166 = 75 cubic feet of sand—or about 2.7 cubic yards. Keep in mind that sand should be evenly graded and compacted, so it may settle slightly over time. Always buy a little extra to cover any adjustments or touch-ups during the leveling process.