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How to Level Ground for a Pool

How to Level Ground for a Pool

You can prepare a proper ground level by marking the perimeter, digging, and cleaning off the substrate. We will then tweak the surface levels with a plank compass, laser level checker, or strings and stakes attached to a spirit level.

Once the level is done, we finish the preparation by toping the area with a base layer, tamping it down, and checking levels for a final pass. We will need to follow a few considerations in each step explained below.

Leveling the ground is the most important preliminary step to ensure a structurally safe pool. Taking the time to level pools will help you prevent wall damage, liner damage, Collapse and most importantly, prevent personal injury in the future.

Why Do We Need to Level Ground for Pool

Leveling substrate and sub-base is a critical preliminary step. Never skip the step. Water has weight, and the hundreds/ thousand gallons poured into a pool have a huge mass. If the weight isn’t distributed properly, there will be pressure on the pool’s isolated sides, making it structurally weak.

An uneven leveled pool can damage the pool frame, pool liner, and wall create property damage from collapse or even personal injury. The pool walls will most likely buckle, twist, or collapse if the pool cannot hold down the wight.

The unevenness can also cause wrinkles on the liner and can be sucked or ripped by pool vacuums when passed on multiple times.

How to Level Ground for a Pool?

Follow the step-by-step procedure to get a perfectly level pool.

Get the Proper Equipment

  • Level Checker / Laser Level Machine with Transit Rod/ Small spirit Level with string attachment module
  • Large 2*4 Wooden Plank greater than the radius of the circle
  • Strings
  • Metal or wooden stakes
  • Spray Can
  • Rake
  • Shovel & Spade
  • Manual Tamper/Plate Tamper Machine/Sod Roller
  • Drill and Drill bit suitable for wood
  • Hammer
  • Base Layer of your choice
  • Earthmoving Equipment Rentals
  • Garden Hose

Mark the Perimeter for Pool

Above-ground pools generally come in three types of shapes. It’s either an oval, rectangle, or circular.

How to Mark Perimeter for Circular Pool

  • First, choose an area in the backyard or your intended location and visually find a patch that looks the flattest to you. Check Local Guidelines for a proper distance of pool from property.
  • Remember to avoid areas with any pipes laid beneath the earth; this includes electrical lines, water pipes, gas lines. 
  • Get a Metal Rebar or wooden stake and drive it to the ground where you want the CenterPoint of the pool.
  • Measure the radius of the circle needed and add roughly 6 inches of a safety distance
  • Take a string of the radius distance and tightly strap it to the CenterPoint rebar or stake, tying a screwdriver or spray canister similar to a pencil for a compass on the other end of the string.
  • Our goal is to make a DIY geometry compass on the ground.
  • Make a circle on the ground by grating the substrate with the screwdriver. Spray the area with paint to mark the ring.compass plank

How to Mark Perimeter for Oval Pool

  • You will get a spec sheet while purchasing the pool, which looks like the chart displayed below. If the pool is small, make a bigger circular perimeter to fit the oval.
  • After you find a visually flat piece of land, drive a wooden or metal stake to mark the center point for the pool.
  • Drive two stakes aligned with the center point on the long side of the oval. The manufacturer’s chart will specify the distance between these stakes.
  •  Follow chart specs and drive C, D, E, and F stakes. It should look like points in a rectangle. If the oval shape is very big, you might need to add midpoints between the stakes to avoid losing alignment.
  • Now drive a nail on the top of the stakes A and B to attach the string. The radius of A and B should be your measuring length for the line. For example, the chart below suggests the radius is 8 feet.
  • Take a spray, and with the tight string from stake A, start making an arc like a geometry compass.
  • Do the same with stake B on the other side to form the arcs on both sides. Join the points E to F and point C to D by hand.
  • Do the outer clearance layer the same way with increased radius. E.g., In the chart below, the string distance to use is 9 feet.
  • You have created an oval perimeter.
Oval Pool Installation Chart

How to Mark Perimeter for Rectangle Pool

Drive four stakes on the corners with needed length and breadth and join them with strings. The difficult thing is to make sure all angled of the rectangle are 90 degrees. We use the Pythagoras theorem to make sure all sides are aligned.

Pythagoras Theorem

(Hypotenuse)2 = (Base)2 + (Perpendicular)2

You can take any two joined lengths and breadth side of the rectangle. Mark the 3 feet mark on one side and a 4 feet mark on the other side of the joined sides.

If the angle is 90 degrees, the diagonal length between these two points will be 5 Feet. Do this for all four sides of the rectangle and make necessary adjustments. Spray the line on the ground to create a ground perimeter.

For big rectangle pool sizes, use 5-12-13 or 8-15-17 measurements. The principle is the same.Pythagoras theorem

Dig The Substrate

Once the area has been marked, dig the marked area. Use a shovel to do it. If the pool size is large, we recommend renting earth moving Equipment from the local rental stores.

Please remember that there mustn’t be any grass, rocks, lumps, or debris on the substrate. All we need is the ground underneath. Remove anything else except the ground material.

Start the Levelling Process

Once the perimeter has been dug, we begin the actual leveling process.

How to Level Circular Pools

Follow the steps below to level circular substrate and sub base.

Make A Plank Compass for the Circle
  • Many people use laser levels to check the level of the surface. Laser levels are the most accurate. If you don’t have one, a plank compass might be the best trick to level the area.
  • Get a 2*4 plank from the local hardware store. The length of the plank should be the radius of the circle or half the diameter.
  • Take your drill and drill a hole on the leaner side of the plank. Drive the plank on the CenterPoint rebar.
  • Tape a level checker equipment to the plank’s middle or the other endpoint. Secure the level checker with twist ties or tape. There should be no slag. You should now have a contraption that looks like a clock’s hand and rotates like a compass.
Start Rotating the Plank and Tweak the Surface
  • When you rotate the plank, notice that excess dirt will come loose with the plank; where the level is not enough, you will see gaps between the plank and the ground.
  • Use your level checker and see if the surface is level. The bubble on the level must be in the middle. Tweak wherever necessary to make the whole circular area level. It is always best to dig high-level surfaces rather than fill low-level surfaces.
    spirit level
  • After a rough pass of the level check, we recommend tamping the whole area down. Spray the area lightly with water and start tamping. Tamping helps in compacting the dirt in the area. You can use a manual tamper or plate tamper machine to do it.
  • Check the surface level again with the plank compass and tweak as necessary.

How to Level Rectangle Pools

The best way to level rectangle pools is by stakes and string or laser level machines.

  • Get some stakes and drive them on opposite sides of the perimeter. Tie the stakes with a string. The string should be tied the same distance from the ground on both sides.
  • Attach a spirit level with attachments to get on the string in the middle of the string. Make sure there is no sag on the line0
    .spirit-level for string
  • Take a tape measure and check multiple areas on the line. The distance between the substrate and the leveled line must be the same for all regions.
  • Do this in various places along the rectangle to maintain a constant level across.
  • Use a machine level with a receiver on a transit rod for a more high-tech approach. Lasers are shot through the machine, and you can lower the receiver to maintain level as the receiver will beep on the needed level.Laser Level Machine

How to Level Oval Pools

Do the circular plank compass and string and stakes method suggested above in combination. A faster way is directly using the laser level machine and transit rod with the receiver.

Add the Manufacturer Specified Subbase Material

  • After the surface is level, we will need to add a subbase material. The generally used material is called masonry sand. These sands are very fine without any pebbles or rocks. Consult the pool company on the preferred subbase for their product and application.
  • There are other alternatives like crushed stone dust. It will entirely depend on the company selling the pool. Sand is the most used subbase material.
    masonry sand
  • For general steps, Spread the sand all over the circular perimeter. The general norm for the thickness of sand needed for the pool is around 2 to 3 inches; consult manufacturing specification for this. Tamp the sanded layer too.
  • Use a rake to spread the sand evenly in the area and check the level with the plank. The level checking is for the substrate and subbase.
  • For pools, if the level is off by three or more than three inches, the pool’s structural integrity is in danger. You can see uneven water surfaces at 2 to 2 ½ inches off levels. The recommended margin of error is around 1 inch or 1.5 inches in the worst-case scenario. This measurement should be your goal.
  • Once everything is set, remove any planks, rebar, stakes and start the installation process.
  • We also recommend floor padding above the base layer so that nothing pokes the pool liner later. You can opt for amour guard or rolled foam made for pools.
  • You will also need to add a base layer around the pool after installation. Common materials used are landscaping rocks like pea gravel. Do not use acid wash stones or mulch as they accelerate moisture input and may cause rust on the metal frames of the pool.
  • Remember always to ground the electricals of the pool.

Related Questions

Can I straight up add the base layer without digging?

Many things can go wrong in the future if you opt to add the base layer without digging directly.

The grass may rot away. The debris can poke the liner of the pool in the future. When we dig the substrate, we tamp down the area, which will help prevent sinking problems later.