Everything you need to know before you break ground on your in-ground steel wall pool.
With most steel wall pools, the decision of whether to go in-ground isn't just a preference — it's a practical question tied to your budget, yard conditions, and long-term vision. Some pools need to be anchored below grade; others perform just as well above. This guide breaks down the pros and cons of digging in a steel wall pool and walks you through the full construction process so you can go in with eyes open.
Should You Place It in the Ground or Not?
This question comes up for almost every steel wall pool project. The short answer: it's entirely possible — but it comes with trade-offs. Let's look at both sides before making any recommendations.
✦ Pros of In-Ground Placement
- Seamlessly integrates into your landscaping for a premium look
- Improved stability — buried walls resist shifting and external pressure
- Can be more insulated than an above-ground alternative
- Less heat loss in windy conditions
✦ Cons of In-Ground Placement
- Adults and elderly individuals can find it disorienting to enter from ground level
- Expensive — excavation, drainage, and reinforcement add up fast
- Steel panels do not absorb solar energy (no passive heating benefit)
- Requires more planning, permits, and professional involvement
- Once in the ground, it cannot be moved
- If the installer makes errors, the correction process is complex
Technology Shift — Yes or No?
Before you dig, take time to think carefully about whether or not to place your pool underground. Digging introduces a significant shift in the pool ecosystem — it moves your pool from a simple, portable water feature into a semi-permanent structure. This also prevents your pool water from receiving direct sunlight and warmth from the sun, which can lead to increased chemical use, heavier filtration loads, and higher costs. The shift should always be weighed against the aesthetic payoff.
A Guide to Installing a Steel Wall Pool in the Ground
Make sure you gather all the necessary tools and supplies before you get started. Here is a list of essential and optional items you'll need:
Digging a Steel Wall Pool: Step-by-Step Process
Mark the Perimeter
If you plan to pour more than 45–50 cm under the ground, your steel wall pool will require corresponding excavation with an increase of about 35cm on each side. Mark the dig zone clearly using stakes and string, then account for drainage and soil displacement before breaking ground.
The Excavation
Dig the area to the correct depth. For a steel wall pool, excavation must account for pool wall height, footer depth, and gravel base thickness. If your steel wall pool is larger than average, expect this step to take considerable time and equipment. Always slope excavation walls slightly to prevent collapse during the construction phase.
Concrete Slab at the Bottom
A reinforced concrete slab at the bottom is essential. Without it, pool walls can sink unevenly and change water levels drastically. This can damage your pool liner and void the warranty. The slab should sit on a clean gravel base and be allowed to cure fully before any pool assembly begins. Gravel as drainage beneath the slab is strongly recommended — gravel should ideally be about 25cm thick.
Gravel as Drainage
You don't want to grow a garden at the bottom of your pool — you need a reliable drainage layer beneath and around the pool structure. Gravel is excellent for this because it allows water to migrate away from the pool walls and prevents soil saturation that could shift the structure over time. The compacted layer should be about 20 cm thick.
Construction Membrane
We recommend using large fibre/big construction membrane or similar rated materials. This membrane separates the structural elements from the soil and prevents roots and moisture intrusion from undermining your build. It should be stored in a cool dry place and handled carefully to avoid tearing during installation.
Reinforcement
Good solid pool walls start with rebar reinforcement in the concrete footer. Place steel rods correctly to ensure they do not make contact with the pool walls themselves — use plastic spacers or foam insulation to keep a protective gap. Without this, corrosion of the pool panels can occur over time and shorten the lifespan of your structure significantly.
Dig, Pour Concrete, Assemble
Important: Do not use heavy concrete for the top slab. You can use thin fibre slabs of around 4 cm on top. You may need a helping hand in some cases to lift and place the panels accurately. There is also usually a small amount of additional work needed at the very end of fitting — a lean concrete backfill works best here. Do not use sand with salt as this corrodes the steel panels over time.
Next Steps in Construction
Once the ground work is complete, you'll move into the exciting part — assembling and waterproofing your pool.
Fleece, Styrodur & Vinyl Liner
Now it's time to assemble your steel wall pool. First, lay the ground fleece — this is your last line of defence between the liner and any sharp edges at the base. Next, use Styrodur (rigid foam) insulation if your design requires it; this is especially worthwhile in colder climates to reduce heat loss from the walls. Finally, install the vinyl liner carefully, beginning from the centre of the pool floor and smoothing outward to avoid creases. Place the liner neatly over the coping and begin filling slowly. The water weight will pull the liner into its final fitted shape.
Lean Concrete Backfill & Wall Insulation
Once the liner is in place and partially filled, backfill the exterior gap between the pool walls and the excavated soil using lean concrete. This secures the walls in position and prevents ground movement from shifting your pool frame over time. If insulation boards were used on the exterior of your pool walls, ensure the lean concrete is poured carefully to avoid displacing them.
- Fill the pool to at least one-third before finalising backfill to stabilise the liner
- Use lean concrete — not sand — to prevent long-term panel corrosion
- Ensure no rebar touches the pool panels directly at any point
- Check the liner for air pockets before water level rises above mid-wall
- Inspect drainage paths are clear before completing backfill
Your Steel Wall Pool — Almost Ready
A few final checks before declaring your project complete: inspect all connections, confirm the filtration system is operating correctly, and ensure the liner is sitting flush at the coping. Once water is at the correct level and the system is running clean, you're ready. We work with pools across the USA and can guide you every step of the way — reach out to our team for personalised advice and pool product recommendations tailored to your backyard.