Shipping Container
Pools: Cost,
Liners & Risks

What is a shipping container pool?

A shipping container pool is a prefabricated pool built from an ISO shipping container or from steel to the same pattern. The builder removes the roof, reinforces the walls, lines the inside with a waterproof coating or membrane, installs the pump, filter and heater, and ships it ready to fill. On site it needs a prepared base, a crane, and hookups for power and water.

How they're built

Shipping containers are made of corrugated weathering steel, usually called Corten, with a plywood floor. Pool builders generally start with new or one-trip boxes: Trek says it uses containers that are "brand new or used only one time," and Ecopool describes its units as single-use. That matters, because the wooden floor of many used containers can hold fumigation residues, and a heavily used box brings dents and rust you'd have to fix before lining it.

Then the box is opened up. Cutting off the roof removes part of what makes a container stiff, since the corrugated sides and roof contribute much of its rigidity, so builders add steel back (Ecopool advertises more than 300 hand welds per pool). Next comes surface prep and the lining, then plumbing, equipment, steps, benches, windows and lights. Modpools quotes 8 to 12 weeks from order to swim; Trek quotes 3 to 8 weeks of production.

Sizes and depths

Standard sizes follow the container: 8 feet wide and 20 or 40 feet long, plus 12- and 16-foot-wide builds made from custom or joined steel. None of them is deep. Expect 4 to 4⅔ feet of water.

At that depth, none of them is a diving pool. They're for cooling off, soaking, playing and short swims, and some add swim jets for exercise. If diving is on the list, you want a different pool.

Shipping container pool vs fiberglass, vinyl and concrete

A container pool isn't a cheap alternative to an in-ground pool. It's a different product: small, shallow, fast to install, and movable. Installed, it lands in the same price band as vinyl and fiberglass in-ground pools. It wins on time and site flexibility, and it loses on depth and on how long a track record the category has.

The honest read: if you want depth, a pool that outlives your mortgage, or the lowest price per gallon of water, a conventional in-ground pool is the better buy. If you have a small yard, a slope, bad soil for digging, a short timeline, or you might move, the container pool's advantages are real. And if all you want is to get wet in July, a traditional above-ground pool at $1,800–$5,000 (HomeGuide) is hard to argue with.

Do shipping container pools rust?

A well-lined, well-maintained container pool shouldn't rust on the water side, because the water never touches the steel. They rust where the lining has a gap: a pinhole missed in testing, a gouge from a dropped ladder, a failed seal at a fitting, or the exterior steel below grade. Rust starts small and local. The job is to find it while it still is.

Inside: pinholes and damage

Any break in the film exposes steel to chlorinated water, and a damaged coating is at risk of rust creeping under the film around it. That's why holiday testing matters at the factory and why you should look closely at the walls every time the water is low. A bonded polyurea lining can be patched locally; Ecopool sells a repair kit for its polyurea for exactly this reason.

Salt water systems

Ecopool says its pools can run a salt chlorine generator. River Pools, which sells fiberglass, warns that salt can speed corrosion of a container's metal parts. Both can be true. Chloride is what makes seawater so hard on steel. With an intact lining, the steel never sees it; at a pinhole, it rusts faster. If you want salt, confirm in writing that the warranty covers it, and check stainless fittings and ladders as carefully as the walls.

Outside and underneath

The outside of the box needs protecting too. Trek, for example, uses a marine-grade exterior finish from Sherwin-Williams. Steel below grade or sitting in wet gravel needs a coating rated for buried service and a base that drains, because standing water against the bottom rail is a corrosion cell you'll never see. Our corrosion prevention coatings page explains how a barrier film stops water, oxygen and salts from reaching steel.

Bonding: the electrical side of a steel pool

A steel pool is conductive, so the electrical code treats it that way. The IRC (following NEC 680.26) requires "all metallic parts of the pool structure" to be bonded with 8 AWG or larger solid copper, along with the perimeter surface out to 3 feet from the pool. Vinyl and fiberglass shells are called nonconductive; a steel box isn't. Make sure the builder provides a bonding lug and your electrician knows it's a metal pool.

Can you put a shipping container pool in the ground?

Yes, if it was built for it. Ecopool says its pools can go fully in-ground, partly in-ground or on the ground; Trek says it engineers for in-ground, retaining-wall and partial-burial installs; Modpools lists in-ground, semi-in-ground and hillside installs. What you can't do is bury any steel box and assume it'll hold. Buried walls carry soil loads that have to be designed for, and an empty buried box can float.

The weight

Water is heavy. A 20-foot container pool filled to 54 inches holds about 4,954 gallons, or 41,300 lb of water, and roughly 46,100 lb with the empty box. A 40-footer holds about 84,400 lb of water, more than the 67,200 lb gross an ISO container is rated to carry as cargo. Spread over a full pad, that's only about 290 psf, well under the 1,500 psf the building code presumes for clay. So bearing capacity usually isn't the problem. Even, compacted, drained support is.

Soil pushes in; water pushes back, until you drain it

The building code's minimum design loads for walls holding back soil run 60–100 psf per foot of depth for walls that can't move at the top, depending on the soil (IBC Table 1610.1). Bury a pool wall 4½ feet in clay and the soil pushes in about 1,000 lb per foot of wall. When the pool is full, the water pushes back about 630 lb per foot. Drain it to reline or repair, and nothing pushes back. The code also says to design for full water pressure from undrained backfill unless there's a drainage system. So the empty, rain-soaked case is the one that has to work.

Empty pools can float

A 20-foot container weighs about 4,850 lb empty. Buried 4½ feet, it only takes about 6 inches of groundwater above its base to lift it. Groundwater at grade would push up with about 44,600 lb. That's plain buoyancy, and it applies to any empty in-ground pool shell, but a light steel box has little weight to resist it. The finished shell's weight differs from the bare container's, so use your builder's number. Drainage, anchoring or a ballast slab solve it. Your engineer decides which.

How we calculated this: gallons = inside length x width x depth x 7.48; weight at 8.33 lb per gallon (USGS). Empty weights are ISO tare weights (20-ft ≈4,850 lb; 40-ft ≈8,380 lb) before the builder's added steel and equipment. Bearing values: IBC Table 1806.2. Wall loads: at-rest pressures from IBC Table 1610.1 (60 psf/ft for gravels and sands, 100 for clayey sands, silts and lean clay), resultant = ½ x pressure x depth². Buoyancy = footprint x submerged depth x 62.4 lb/ft³.

What an engineer will want to see

• The builder's approval for the install type you want, in writing, with its reinforcement drawings.
• Soil and groundwater. Angi puts soil testing at $700–$2,200. On a site with a high water table, it's cheap insurance.
• Drainage. Free-draining backfill and a path for water away from the walls and base.
• A plan for draining the pool someday: when, how, and what holds the walls and base down while it's empty.
• Exterior protection for the buried steel, since you won't see it again.
• Rooftop or deck installs always need a structural engineer; Modpools says so too.

Can you heat a shipping container pool?

Yes. Container pools use the same heat pumps and gas or propane heaters as any pool, and Modpools offers gas and electric heaters in its factory equipment package. The difference is the walls: on an above-ground pool, bare steel sits between warm water and outdoor air with almost nothing to slow heat down. Insulate those walls and a surprising share of the heating bill goes away.

How to size the heater

The Department of Energy's sizing rule is pool surface area x temperature rise x 12, in Btu per hour, where the temperature rise is your target water temperature minus the average air temperature for the coldest month you'll swim. It assumes a 1–1.25°F per hour warm-up and 3.5 mph of wind. DOE lists standard heat pump sizes of 75,000, 100,000 and 125,000 Btu, with coefficients of performance from 3.0 to 7.0, working efficiently above about 45–50°F.

Why the walls matter on a steel pool

That DOE rule is built around the water surface, and evaporation is by far the biggest heat loss from any pool. But an in-ground pool's walls sit against soil, while an above-ground container pool's walls face open air through a sheet of steel. The only real resistance is the thin air film on the outside, about R-0.25 in summer. Two inches of closed-cell spray foam at R-6.5 per inch makes that wall about fifty times more resistant.

How we calculated this: heater size = surface area x (water − air) x 12 (DOE). Wall loss = exposed wetted wall area x temperature difference ÷ R, with R-0.25 for the summer exterior air film (Colorado Energy R-value table) and the steel and water side treated as negligible, plus R-6.5 per inch for ArmorFoam closed-cell or R-5 for XPS. Energy: 3,412 Btu per kWh, 100,000 per therm, 91,452 per gallon of propane. Prices: EIA (electricity 18.31¢/kWh, July 2026; gas about $1.48/therm from EIA's 2025 residential average; propane $2.674/gal). Steady state; sun on the walls will offset some daytime loss.

Insulating the walls

The practical way is foam on the outside of the steel, then cladding over it. Closed-cell spray foam bonds to the corrugations with no gaps; foam board is cheaper and easier for a DIYer but harder to fit to corrugated steel. Trek lists wall insulation as an add-on, and Modpools calls its shell insulated, so ask what's included. For in-ground pools, only the part of the wall above grade is exposed to air. Our shipping container insulation guide covers foam on container steel in depth, and our closed-cell spray foam guide has the specs.

Winter use

Heat pumps lose efficiency below about 45–50°F, so year-round swimming in a cold climate usually means gas or propane, a good cover, and insulated walls. The cover matters most: DOE says covers can cut heating costs by 50–70%, make-up water by 30–50% and chemical use by 35–60%. If you're not heating through the winter, follow the builder's winterizing instructions to the letter, and ask how freeze damage to plumbing and equipment is handled under the warranty.

Are shipping container pools worth it?

They're worth it when their strengths match your site: small or sloped yards, poor ground for digging, a short timeline, a rental or second home, or a real chance you'll move. They're not worth it if you want depth, the longest possible life, or the lowest price for the most water.

One more factor: resale. Angi reports that an in-ground pool can add around $36,700 in home value, versus about $250 for an above-ground pool, with a wide range of returns. Where a container pool falls depends on whether buyers in your market see it as a permanent feature or a removable one.

Shipping container pool FAQ