Save Your Pool Liner with Proper Sand Leveling

Installing an above-ground pool in your backyard can provide years of fun for the whole family. But improperly preparing the ground beneath the pool can lead to a sagging frame, punctured liner, and constant headaches. By taking time to level the surface with a protective layer of sand, you'll avoid many issues down the road while creating a smooth pool base.

Read on to learn the proper process of using sand for pool installations.

Choose the Right Sand for Pool Bases

Not all sand is created equal when it comes to pool base preparation. The sand particle size and shape will determine how easily it compacts and drains underneath the liner. Generally, a coarse builders' sand with angular grains is optimal for keeping your pool stable season after season.

Sand Type Comparisons

Concrete sand contains fine particles that pack tightly together when wet. While great for mixing concrete, this sand will retain moisture and provide too rigid of a base for polymer pool walls. White sand is also quite fine and prone to shifting.

For pool installations, an angular yellow masonry sand provides excellent stability and drainage capacity once firmly compacted. Also called builders' sand, it compacts well while still allowing water flow. Compared to rounded river sand, the masonry sand's sharp edges help it stay firmly in place under and around your pool.

Other Sand Considerations

It's important pool base sand has uniform grain sizes for even compaction. Single-sized particles with some fine and coarse grains blended compact better. Sand with organic residues like topsoil will get muddy and be harder to level.

Ideally, the sand shouldn't have over 5% passing a 200 sieve. This indicates finer grains that inhibit proper drainage. Too many fine particles may also bind together into a solid mass that causes pool settling.

Calculate How Much Sand Your Pool Needs

Now that you know which sand to use, determining the required amount is essential for proper coverage. You'll need an even 4-6 inch layer smoothed across the entire pool's footprint. Measure where your pool will sit and calculate the surface area.

For example, an 18 x 33 foot oval pool contains around 500-600 square feet. At a 4 inch depth, you'd need 20 cubic yards of sand for proper coverage. Add an extra 10% to be safe. Sand is sold by the ton or half-ton bulk bags at most landscape supply stores for pickup or delivery.

Prepare the Ground Under Your Pool

Installing your oval or round pool right on top of grass and tree roots is asking for trouble. Remove all vegetation, sticks, and large stones from the area first. Use a garden rake to loosen packed soil to a depth of 2-3 inches for better leveling.

We also recommend laying an overlapping weed-block landscape fabric. This blocks sunlight to prevent grass and weeds from poking through the liner. Just cut an "X" for the skimmer and return jets.

Spread and Level the Sand

When your reinforced sand arrives, carefully spread it using a steel rake in every direction to fill in low areas. For proper coverage, remember that a little extra sand is better than not enough. Level uniformly while trying to maintain an even depth.

Aim for a variation of no more than 1/4 inch depth when you check with a long board and spirit level. As you add and move material around, tamp the entire area down frequently with a hand tamper.

Fully Compact the Sand Layer

This step makes all the difference for long-term stability. Compacting firms up and smooths out the sand flat so your pool walls sit solidly. If sand shifts once the liner is filled with gallons of water, a failure is imminent.

For best results, rent a vibrating plate compactor from your local home improvement store. Make passes length and widthwise over the sand, tamping until solid. Alternatively, you can use a hand tamper in combination with your own body weight.

Protect the Sand Surface

To preserve the smooth finish, avoid walking on the leveled area before pool construction. Install 6 inch foam pool cove edging secured with long spikes around the entire perimeter before placing walls.

Then cover the compacted sand with construction sheeting until you're ready to carefully place your pool atop the protected base. This keeps rain, wind, and debris from disturbing level.

Filling the Pool Over Sand

With walls braced per manufacturer instructions and liner overlapping dirt areas, carefully start to backfill inside with 1-2 inches of water initially. Make sure no liner lifts or pool shifts on the sand and check the water level all around.

Once everything looks good, continue filling the pool completely and recheck for smooth, flat water across the length looking for humps. Anchor the outer pool frame well to ground stakes to prevent floating or creeping.

Maintaining Sand Under Your Pool

Your properly prepped sand base needs some occasional upkeep too for maximum longevity. Poke around the outside liner regularly to ensure no washing out or settling gaps beside the frame. Refill any eroded spots as needed to prevent sinking.

Significant rains may reveal slight depressions. Add bagged sand at these spots and work flat from the pool wall using a tamping board before water can settle heavily.

When done right, a sand pool base provides lasting stability for the weight of your above-ground pool. Compared to harder surfaces like concrete that settle unevenly, sand allows for adjustment and avoids cracking issues.

Combined with proper perimeter drainage and a quality pool liner, starting below surface with durable yellow builders sand will keep your pool looking balanced for many swim seasons.