Fibreglass Pool Shell: Materials, Strength & Weight
What a fibreglass pool shell is made of, how the laminate is built, the Australian standard it meets, and what our shells weigh by model.
Written by Tehbyn Nova, Head of Operations & Growth · Technically reviewed by Caleb Druhan, General Manager (QBCC licence 15087383) on
Published
What is a fibreglass pool shell?
A fibreglass pool shell is a one-piece swimming pool manufactured in a factory. It is delivered to the site by truck and installed in an excavated hole. The finished interior surface and plumbing openings are integrated into the composite laminate. The shell is structurally self-supporting when delivered.
A fibreglass pool shell is different from a panel pool assembled on site or a vinyl liner pool installed over a frame. The shells we install are manufactured by Aqua Technics at its plant in Jandakot, Western Australia.
Each shell’s dimensions are determined by its mould and published as a specification. The range includes:
- Lengths from 3.00 m for the Infinity 3 to 11.48 m for the Saint Azur
- A maximum width of 4.45 m for the Saint Azur
- A maximum depth of 2.00 m for the Amalfi, Kensington and Saint Louis
What is a fibreglass pool shell made of?
A fibreglass pool shell is a composite laminate made from glass reinforcement and resin. It consists of several layers. From the water-facing surface to the ground-facing surface, these layers are:
- Gelcoat. The gelcoat is the coloured interior surface. It contains the water and is the surface swimmers touch. It is sprayed into the mould before the glass layers are added. It seals and finishes the laminate but does not carry structural loads.
- The vinyl-ester barrier coat. This layer sits directly behind the gelcoat. It resists water absorption and helps prevent osmotic blistering.
- The structural glass laminate. This layer consists of glass reinforcement saturated with resin and applied in multiple plies. It carries structural loads, maintains the pool's shape, and resists pressure from the water and surrounding ground. It also makes the shell self-supporting before backfilling.
- A core or reinforcement layer. This layer sits within or behind the structural laminate. It increases the stiffness and strength of the laminate.
- An external seal or flow coat. This is the outermost layer. It seals the exterior surface of the laminate against ground moisture.
Layer counts and reinforcement materials vary by manufacturer.
A published layer count applies only to that manufacturer's shell and manufacturing process.
Core and reinforcement systems also differ. Manufacturers may use polypropylene honeycomb, structural honeycomb, a ceramic-composite core, laminates containing Kevlar, carbon or basalt fibre, or strengthening ribs moulded into the wall. A material used by one manufacturer does not indicate what another manufacturer uses.
The shells we install use a Graphene Nano-Tech interior surface system. This system is covered by granted Australian patent AU 2021240305 and the Lifetime Interior Surface Guarantee, conditions apply. Graphene Nano-Tech is an interior surface system, not a structural core. Our shells do not suffer osmosis.
How strong is a fibreglass pool shell, and is it meant to flex?
A fibreglass pool shell is designed to flex as the surrounding ground moves. A concrete pool shell is rigid and resists the same movement. If the ground moves far enough, a concrete shell can crack. A fibreglass laminate can absorb some movement without structural damage.
The gelcoat has a lower tolerance for movement than the structural laminate. Excessive flexing can cause spider cracking, which appears as fine hairline cracks in the coloured surface. This damage is cosmetic and does not affect the strength of the shell.
More significant movement can cause the entire shell to shift. A fibreglass pool bulging or popping out of position is different from spider cracking because it affects the shell’s position in the ground.
The shell is self-supporting when delivered. After placement, the surrounding installation materials hold it in position. The shell is lowered onto a bedding layer. The bond beam and backfill secure the top edge and fill the space between the shell and the excavation. AS 1839:2021 governs this installation work.
What Australian standard does a fibreglass pool shell have to meet?
A fibreglass pool shell must be designed to AS/NZS 1838:2021 and installed to AS 1839:2021.
- AS/NZS 1838:2021 applies to the design of the pool shell.
- AS 1839:2021 applies to the installation of the pool shell.
The shells we install are manufactured under licence BMP 520101. Before signing a contract, ask the builder to provide:
- The design standard for the shell.
- The manufacturing licence number.
A statement that a shell “exceeds Australian standards” does not identify either item and cannot be verified without further information.
Installation requires prior approval from the local building regulator. This requirement applies to in-ground and above-ground swimming pools, including fibreglass pools.
The shell we install has two guarantees, subject to their conditions:
- Extended Lifetime Structural Warranty for the shell structure.
- Lifetime Interior Surface Guarantee for the interior surface.
Our installation work is covered by the MFP Easy 7-Year Workmanship Guarantee. This guarantee applies to work completed on site, not to the manufactured shell.
How is a fibreglass pool shell manufactured?
A fibreglass pool shell is manufactured in a factory using a mould that defines the pool’s finished shape. Each shell is produced separately in the following sequence:
- Apply the gelcoat. The gelcoat is sprayed into the mould before the glass and resin are added. Because the mould face forms the pool’s interior surface, this step creates the finished surface.
- Apply the resin and glass. Layers of glass reinforcement and resin are applied over the cured gelcoat. A core or reinforcement layer is also added. These layers form the structural laminate.
- Cure the shell. The shell remains in the mould until the resin hardens and the laminate can hold its shape.
- Remove the shell from the mould. The cured shell is lifted from the mould as one piece.
- Trim the shell. Excess laminate is removed.
- Inspect and test the shell. The completed shell is inspected and tested at the factory. It is then despatched as one piece for installation by crane.
Factory production allows temperature and humidity to be controlled while the gelcoat cures. Production data is recorded for each shell. Material weights, wall thickness and hardness are measured and logged against the individual pool.
Hand lay-up can cause minor variation between shells. This can appear as small differences in surface shade or texture. These differences are cosmetic.
Openings for the skimmer box and drains and return fittings are included during shell production. They are not cut into a wall on site.
After delivery, the shell can be installed and holding water in about 5 to 7 days. Including the surround, a complete fibreglass pool project takes about two to six weeks. A concrete pool takes three to six months.
The mould also determines the available shape, size and depth. Buyers select from existing models and cannot order a custom shell. Gelcoat colour and the surround can still be selected.
How much does a fibreglass pool shell weigh, and how does it get into the hole?
Dry shell weights range from 341 kg for the 4.0 m × 2.0 m Elba spa to 1,286 kg for the 11.48 m Saint Azur.
| Model | Size | Dry shell weight | Water volume |
|---|---|---|---|
| Serenity | 4.00 m × 2.50 m | 379 kg | 9,500 L |
| Portofino | 5.50 m × 2.50 m | 498 kg | 13,200 L |
| Empire | 6.00 m × 3.00 m | 622 kg | 18,700 L |
| Oxford | 7.00 m × 3.00 m | 738 kg | 26,230 L |
| Castello | 7.50 m × 3.60 m | 805 kg | 25,600 L |
| Valentina | 8.00 m × 4.00 m | 909 kg | 38,700 L |
| Westminster | 9.00 m × 4.00 m | 988 kg | 39,490 L |
| Saint Azur | 11.48 m × 4.45 m | 1,286 kg | 52,780 L |
Shell weight determines how it is moved from the truck into the excavation. Two-thirds of our installations use a crane. The other installations use a truck hoist. Excavators are not used to place fibreglass pool shells.
The standard crane is a 20-tonne Franna. If a larger crane is required, the crane is selected based on lift reach. The reach bands are:
- 0 to 15 m
- 15 to 20 m
- 20 to 30 m
- 30 to 36 m
- 36 to 48 m
Longer lift distances require larger cranes.
Can you buy a fibreglass pool shell on its own?
Yes. Several Australian suppliers sell fibreglass pool shells separately, with or without an equipment kit, and deliver them across Australia.
MFP Easy sells installed pools only. We do not provide shell-only pricing.
If you are comparing pool costs, use the installed price of a fibreglass pool. A shell-only purchase does not include installation. The shell must be installed to AS 1839:2021 and approved by the local building regulator before installation. It is not covered by the MFP Easy 7-Year Workmanship Guarantee, which applies to our installation work.
| Pool size | Length | Depth | Installed from |
|---|---|---|---|
| Round pools | 3m to 4m | 1.45m level | $47,233 |
| Small pools | 4m to 5.5m | 1.0m to 1.78m | $46,053 |
| Medium pools | 6m to 7m | 1.0m to 1.88m | $55,003 |
| Large pools | 7.2m to 8m | 0.98m to 1.96m | $60,475 |
| Family pools | 8.25m to 11m | 1.0m to 2.0m | $69,428 |
Live all-inclusive installed pricing for standard site conditions in South East Queensland — updated straight from our quoting system.
FAQs
How long does a fibreglass pool shell last?
A fibreglass pool shell typically lasts 30 years or more. The Extended Lifetime Structural Warranty covers the shell’s structure. The Lifetime Interior Surface Guarantee covers its interior surface. Conditions apply to both. The shell is designed to remain in the ground for its full service life.
What happens to a fibreglass pool after 25 years?
After 25 years, a fibreglass pool shell remains within its service life of more than 30 years. Our shells do not suffer from osmosis. The Lifetime Interior Surface Guarantee covers the interior surface, subject to conditions. The Extended Lifetime Structural Warranty covers the one-piece composite laminate structure.
What is the downside of a fibreglass pool?
The main limitation of a fibreglass pool is its fixed shape. Manufacturers produce each shell from a pre-made mould. Buyers must choose from existing models and cannot specify a custom shape, size, or depth. Gelcoat colour and pool surrounds can be customised. Available models range from 3.00 m to 11.48 m in length.
Does a fibreglass pool need concrete around it?
Yes. A concrete bond beam is installed around the top edge of the fibreglass pool shell. It holds the shell in position in the ground.
How much is a fibreglass pool shell on its own?
We do not provide shell-only pricing. We sell installed pools, so we quote the total installed price.
A shell must be installed to AS 1839:2021 and approved by the local building regulator before it can be used as a swimming pool. Other Australian suppliers sell shells and kits separately, with or without an equipment kit.
