Fibreglass Pool Pros and Cons: Benefits, Faults & Costs
The real advantages and drawbacks of a fibreglass pool in Australia: what the moulded shell does well, what it can't do, and what goes wrong.
Written by Tehbyn Nova, Head of Operations & Growth · Technically reviewed by Caleb Druhan, General Manager (QBCC licence 15087383) on
Published
Direct answer
A fibreglass pool is manufactured as a finished shell. The buyer selects a model from a range of moulds, and the site is excavated to fit it. In comparison, a concrete pool is built on site to a specific design. This difference determines many of the benefits and limitations of fibreglass pools.
Fibreglass is spelled “fiberglass” in the US. Both terms refer to the same product. MFP Easy installs more than 250 pools each year across South East Queensland and manages these benefits and faults during installation.
What are the pros and cons of a fibreglass pool?
A fibreglass pool shell is manufactured and gelcoated in a factory, then delivered to the property as one piece. Its smooth, non-porous surface reduces algae growth, brushing and chemical use compared with a rendered concrete pool.
Installation is also faster than building a concrete shell on site. We set the shell into the excavated hole 2 to 7 days after digging starts. If you buy, the contracted time from purchase to swimming is 11 weeks.
The main limitation is the fixed design. You must choose from the available moulds, including their shape, size and deep-end depth. The shell must also be delivered by truck and moved into position through a side path or by crane. Installation quality is the main risk because poor installation can cause bulges, cracks and leaks.
| Issue | Fibreglass pool | What that rules in or out |
|---|---|---|
| Shape and size | Chosen from a range of moulds; Australian shell ranges run roughly 4 m to 13 m in length, with deep ends of 1.85 m to 2 m | Rules out a custom outline, nominated length or deeper deep end. A concrete pool can be formed on site to a specified shape, size and depth |
| Surface | Gelcoat formed in the mould; smooth and non-porous | Reduces algae growth and does not support acid washing. A rendered concrete surface is porous and requires periodic resurfacing |
| Build time | Shell set 2 to 7 days after digging starts; 11 weeks from contract to swimming if you buy | The shell is manufactured before excavation and installed whole. A concrete pool is formed, cured and finished on site over several months |
| Getting it in | Delivered whole on a truck, then moved down a side path or lifted by crane | Requires a clear side path or a suitable crane setup position |
| Cracking | The laminate flexes with ground movement | Reduces the risk of structural cracking associated with a rigid concrete shell. Flexing beyond the shell’s limit can cause gelcoat spider cracking, which appears as hairline surface cracks |
| Renewal | The finish and structure are made from the same material | Does not require liner replacement or a render resurfacing cycle. A cut and polish every 5 to 10 years can restore colour and gloss |
| Repairs | Gelcoat damage is repaired in place | Repairs may remain visible on dark colours and multi-layer metallic or flake gelcoats. Single-layer solid colours are easier to match in the field |
| Risk | Outcomes depend mainly on installation quality | Builder selection is important. Poor installation can cause bulges, cracks and leaks |
What are the advantages of a fibreglass pool?
Fibreglass pools have a moulded surface and are manufactured off site. The six main benefits are:
- Non-porous surface. The gelcoat cures against the mould, creating a smooth surface with no open pores. This gives algae less opportunity to attach. Compared with a rendered concrete pool of the same volume, a fibreglass pool requires less brushing and fewer chemicals. It does not require acid washing.
- Faster installation. A purchased fibreglass pool takes 11 weeks from contract to swimming. The shell is installed 2 to 7 days after excavation starts. Concrete pools are formed, cured and finished on site over several months. Fibreglass shells are manufactured before site work begins, which reduces the installation period.
- Lower running costs. The non-porous gelcoat requires less cleaning and fewer chemicals than rendered concrete. The ten-year cost of fibreglass pool maintenance includes power, chemicals and servicing. It does not include acid washing, replastering, retiling or liner replacement.
- No separate surface to replace. The finish and structure form a single shell. Vinyl liner pools require liner replacement, while concrete pools require resurfacing. On a fibreglass pool, the finish can lose colour and gloss. Common causes include over-chlorination below the waterline and UV exposure above it. A cut and polish every 5 to 10 years restores the surface.
- More than 30 years of shell life. A properly manufactured, installed and maintained fibreglass pool can last more than 30 years. The installed cost can be divided by 30 to calculate an annual ownership cost. Our shells comply with AS/NZS 1838:2021 and include an Extended Lifetime Structural Warranty. Conditions apply.
- Smooth surface for family use. The moulded shell is smooth and has no abrasive areas or sharp edges. Steps, step entries and ledges have a moulded non-skid texture for grip. Swimming surfaces remain smooth.
What are the disadvantages of a fibreglass pool?
Fibreglass pools have fixed shapes and sizes. They also require suitable site access and generally cost more upfront than vinyl liner pools.
Fixed shapes and sizes. Fibreglass pool shells are made using existing moulds. Buyers select a model with a predefined shape, step layout, and depth profile. Australian models are approximately 4 m to 13 m long and have deep ends of 1.85 m to 2 m.
Concrete pools are built on site and can have custom shapes, sizes, depths, and finishes. See fibreglass pools compared with concrete pools for more information.
The outline of a fibreglass pool cannot be changed. However, buyers can select some features, including the gelcoat colour and surrounds. See which parts of a moulded pool can still be selected. Available medium-sized models include:
Prices are live all-inclusive installed prices (pool, standard installation, filtration and handover) for standard site conditions in South East Queensland.
Transport limits. A fibreglass pool shell is transported to the site in one piece. Public road transport limits the shell’s width and depth. As a result, Australian fibreglass pools generally have deep ends of 1.85 m to 2 m. These limits do not apply to concrete pools because they are built on site.
Site access costs. The equipment required for excavation depends on the narrowest access point between the kerb and the excavation:
- 1.57 m or more. Full-size plant.
- 1.38 m to 1.57 m. A mini-excavator with a standard bobcat.
- 1.38 m or less. A mini machine.
Site access also affects spoil removal. Spoil can be loaded directly into a truck when access is at least 3 m wide and the excavation is within 5 m of the truck. Otherwise, the spoil must be moved from the excavation to the truck. Pricing uses cart-distance brackets of 0 to 5 m, 0 to 20 m, 20 to 40 m, and 40 to 60 m.
A crane may be required when there is no clear side access for moving the shell into the excavation. Two in three installations use a crane. A standard installation includes an allowance for a 20-tonne Franna crane. The required crane class depends on the lift distance:
| Lift distance | Crane class |
|---|---|
| 0 to 15 m | Small slew, 13 to 16 tonne |
| 15 to 20 m | Medium slew, 40 tonne |
| 20 to 30 m | Standard slew, 55 to 60 tonne, no counterweight |
| 30 to 36 m | Standard slew with counterweight, 60 tonne |
| 36 to 48 m | Large slew, 80 to 120 tonne |
A longer distance between the crane setup position and the excavation requires a larger crane. Crane pricing is based on this distance.
Higher upfront cost than vinyl liner pools. A fibreglass pool generally costs more upfront than a vinyl liner pool and less than a concrete pool of the same size. The price includes shell manufacturing, transport, and site equipment. The following costs apply to every installation:
| Pool size | Length | Depth | Installed from |
|---|---|---|---|
| 3m to 4m | 1.45m level | $47,233 | |
| 4m to 5.5m | 1.0m to 1.78m | $47,706 | |
| 6m to 7m | 1.0m to 1.88m | $56,656 | |
| 7.2m to 8m | 0.98m to 1.96m | $60,475 | |
| 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.
Installation quality risks. Incorrect installation can cause bulges, cracked gelcoat, leaks, and spider cracking. Installation quality is the main factor that can reduce the lifespan of a fibreglass pool. Other factors include water chemistry, low or empty water levels, groundwater, and UV exposure.
Our installations include the MFP 7-Year Workmanship Guarantee. Conditions apply. We provide installations across Brisbane, Gold Coast, Ipswich, Logan, Moreton Bay, Noosa, Redlands, Sunshine Coast, Lockyer Valley, and Somerset.
What goes wrong with fibreglass pools?
Fibreglass pools can develop six common faults:
- Gelcoat spider cracking
- Bulging
- The shell lifting out of the ground
- An out-of-level shell
- Gelcoat fading and loss of gloss
- Osmotic blistering
These faults are caused by installation or ground conditions, or by wear to the finish over time.
A fibreglass laminate can flex as the ground moves. This can help prevent the structural cracking that may occur in a rigid concrete shell. Excessive movement can still cause spider cracking in the gelcoat. Spider cracks are hairline cracks in the surface finish. They are not structural failures in the laminate.
Improper installation is the most common cause of spider cracking. It can also cause cracks, leaks, and the lifting and wall-movement risk associated with a shell that bulges or rises out of the ground.
| Fault | What causes it | Install fault or material fault |
|---|---|---|
| Gelcoat spider cracking | Pressure on the shell beyond what the gelcoat can flex to | Install fault. Improper installation is the most common cause |
| Bulging | An inexperienced or sloppy install, which causes bulges, cracks and leaks | Install fault |
| The shell lifting or floating | An empty or part-empty shell sitting on wet ground. A shell held at its correct water level has no buoyancy and is not at risk | Install and maintenance fault. Not specific to fibreglass: a concrete or vinyl liner pool can lift too where the install or the upkeep is wrong |
| Out of level | A shell that was not set level during the install | Install fault |
| Gelcoat fade and gloss loss | Over-chlorination below the waterline and UV above it | Finish wear, not structural wear |
| Osmotic blistering | Water working in behind the gelcoat and reacting with the resin beneath, lifting small bumps in the finish | Laminate fault, and the reason the vinyl-ester barrier layer exists |
Osmotic blistering mainly affects older shells. It occurs when water passes behind the gelcoat and reacts with the resin underneath. The reaction creates small, raised bumps in the finish.
A vinyl-ester barrier behind the gelcoat resists water absorption and protects the resin. Blistering can occur in laminates that do not have this barrier. Our shells use a Graphene Nano-Tech laminate, patent AU 2021240305, and include a Lifetime Interior Surface Guarantee. Conditions apply.
Gelcoat damage can be repaired on site. Matching the repaired area to the factory finish is the main difficulty. Damage can occur during transport or installation, or as a result of a structural fault.
Dark colours can be difficult to match. Metallic and flake gelcoats can also be difficult to repair because they contain multiple layers. Repairs may be visible in direct sunlight. Single-layer solid colours are easier to match on site.
Fading and loss of gloss are surface wear, not damage. Cutting and polishing the surface every 5 to 10 years can restore its colour and gloss.
Do people regret buying a fibreglass pool?
Regret usually relates to the selected pool, not the fibreglass material. The main issues are:
- Size
- Depth
- Position
- Budget for the surround
Size and depth are fixed by the selected shell. A shell cannot be lengthened after installation, and its depth profile cannot be changed. Buyers should select a model that provides the required dimensions and depth before installation.
The pool position is fixed when excavation begins. It depends on site constraints and where the owner wants the pool to be visible from.
Buyers also often underestimate the cost of the surround. A pool contract stops at the coping, which is specified as Category 1 or Category 2. Paving, landscaping, and the levels connecting the pool area to the house require a separate budget.
The main decision is not whether to choose fibreglass. It is which model, depth, and position to choose, and how much budget to reserve for the surrounding area.
Are fibreglass pools slippery?
Fibreglass pools have textured, non-slip surfaces in areas where people stand or enter and exit the pool. These areas include steps, step entries, ledges, and beach entries. Other surfaces are smooth.
The gelcoat floor is smooth when wet or dry. Gelcoat is non-porous, which helps prevent algae from attaching to the floor and walls.
The texture is built into the mould before the pool shell is made. It cannot be added after the gelcoat has cured. If the floor feels too smooth, use the pool’s existing textured surfaces for standing and entering the water.
You can choose the colour and finish when ordering. The texture pattern, shape, and depth profile are determined by the pool model.
Can a fibreglass pool make you itch, or leave fibres in the water?
No. Under normal conditions, a cured fibreglass pool shell does not release glass fibres into the water or cause itching.
A fibreglass pool shell has three layers:
- Gelcoat: The coloured, waterproof surface that contacts swimmers and pool water.
- Vinyl-ester barrier layer: Helps prevent water absorption.
- Structural laminate: Contains glass fibre bound in cured resin.
Raw, unbound fibreglass can cause itching and may be present on a freshly cut laminate edge. In a completed pool shell, cured resin binds the fibres, and the gelcoat covers the layers under the surface. Swimmers and pool water do not contact the glass fibre.
A rough surface usually indicates a gelcoat defect, not exposed glass. Gelcoat can chip around fittings, develop fine cracks, or become dull over time. If damage extends through the gelcoat to the laminate, repair it to reseal the surface.
Pool water chemistry is a more common cause of itching after swimming. High chlorine levels or an incorrect pH can irritate skin. Test the pool water to check its chlorine and pH levels.
Are fibreglass pools toxic?
No. A cured fibreglass pool shell is chemically stable in water. Swimmers contact the gelcoat surface, not the resin or glass fibre.
The shell consists of glass fibre bound in cured resin. The gelcoat is formed over the shell in the mould. Resin off-gasses during curing, which occurs at the factory. The shell is fully cured before delivery, so it does not off-gas after installation.
Gelcoat is a continuous, non-porous layer between the pool water and the laminate. Standard pool safety requirements still apply, including fencing, supervision and water chemistry.
What does a fibreglass pool feel like to swim in?
A fibreglass pool has a smooth gelcoat surface. It feels warm underfoot and when swimmers stand on or push off the walls. Unlike rendered concrete, the surface is not abrasive and is less likely to scrape toes or knuckles.
The gelcoat shell is rigid. It does not move underfoot like a vinyl liner, which is a membrane rather than part of the pool structure.
The shell is made as one continuous piece. It has no grout lines, tile edges or seams. There are no joins at the steps or corners that can catch toes.
FAQs
What is the average lifespan of a fibreglass pool?
A fibreglass pool shell can last more than 30 years when properly manufactured, installed, and maintained. The laminate forms the structure and is covered by an Extended Lifetime Structural Warranty. Conditions apply.
The finish may fade over time. UV exposure can affect colour and gloss above the waterline, while over-chlorination can affect them below the waterline. A cut and polish every 5 to 10 years can restore the finish.
Our shells are built to AS/NZS 1838:2021.
How often do fibreglass pools crack?
Fibreglass pools can develop gelcoat spider cracks. These are hairline cracks in the surface finish caused by pressure on the shell beyond the gelcoat’s flexibility. They are cosmetic and do not indicate structural failure.
Structural cracks affect the laminate and are associated with installation quality and ground movement. They are not caused by the shell material itself.
Which pool is better, fibreglass or a vinyl liner?
Fibreglass and vinyl liner pools use different waterproof layers.
- A vinyl liner pool uses a replaceable membrane to hold the water. The liner must be replaced when it wears or tears.
- A fibreglass pool combines the structure and finish in one shell. It has no membrane to replace, but the gelcoat ages over time.
A vinyl liner pool has a lower upfront cost. A fibreglass pool has a lower lifetime cost.
Are fibreglass pools safe?
Yes. A cured fibreglass pool shell is chemically stable in water. Swimmers touch the gelcoat, which is a continuous, non-porous layer over the laminate. They do not touch glass fibre.
Resin releases gas during curing. This process is complete before the shell leaves the factory. A finished pool does not release gas into the water.
As with concrete and vinyl liner pools, safety depends on fencing, supervision, and water chemistry.
How long does a fibreglass pool take to install?
A fibreglass pool typically takes 11 weeks from contract signing to swimming. The shell is installed 2 to 7 days after excavation begins. In comparison, a concrete pool is formed, cured, and finished on site over several months.
Do fibreglass pools fade in the sun?
Fibreglass pool finishes lose colour and gloss over time. This affects the finish, not the structure.
UV exposure is the main cause of fading above the waterline. Over-chlorination is the main cause below the waterline.
A cut and polish every 5 to 10 years restores the colour and gloss. Neither type of fading affects the laminate underneath.