Fibreglass vs concrete pools
We build both, so we have no reason to push you towards one. Here is an honest comparison — where each type wins, what they cost to own, and how to decide.
Speed and surface, or total freedom
A pre-moulded fibreglass shell is manufactured in our Hartbeespoort factory, delivered in one piece and installed in days. A concrete pool is built in place, shaped to whatever you want, and takes weeks. Fibreglass wins on speed, surface and running cost. Concrete wins on freedom of shape, size and depth. Built properly, both will outlast the bond on your house.
In practice the decision is usually made by the site and the brief rather than by the material. Awkward access, a tighter budget and a standard rectangle or freeform shape point to fibreglass. A fifteen-metre lap pool, a beach entry, a raised infinity edge or a shape that has to work around an odd corner point to concrete.
How the two compare
Where each one wins
- You want to be swimming this month rather than this season.
- You want the lowest running cost and the least weekly work.
- One of our 69 shells fits your space and your brief.
- Access allows the shell to be delivered and craned or rolled into place.
- You want a fixed, transparent price up front — our instant estimate gives you one in about two minutes.
- Your shape, length or depth profile is outside any moulded shell.
- You want features built in — beach entry, tanning ledge, infinity edge, integrated spa.
- Access is too tight to deliver a shell of the size you actually need.
- You are working around an existing structure, a slope or a level change.
- You want a fully bespoke design and are comfortable with a longer build.
What it costs after the invoice
Comparing sticker prices only tells you half the story. A fibreglass shell is usually cheaper to buy and cheaper to run — less chemical, less brushing, no interior renewal cycle to budget for. A concrete pool costs more to build and carries a resurfacing bill roughly once a decade, but it buys a pool that could not have existed any other way.
So the honest framing is this: if a moulded shell does what you want, fibreglass is the better value. If it does not, concrete is not the expensive option — it is the only option, and it is worth doing properly.
Either way, the money that quietly disappears is in the details: pump and filter sizing, the plant room, the backfill, the paving and the finishes around the water. That is where a cheap quote turns expensive.
Three steps to a decision
Measure the area you can give the pool, then walk the route from the street to the hole. Access alone rules a great deal in or out before anything else matters.
Length for lap swimming, a shallow ledge for toddlers, a specific shape, a raised edge. If any of those cannot be met by a moulded shell, you already have your answer.
Get an instant fibreglass estimate online and ask us to quote the concrete equivalent for the same brief. Comparing two real numbers beats comparing opinions.
We compete in both categories
Cosmo builds fibreglass and custom concrete pools side by side, and both show up in our competition work: our 2025 national award entries covered nine fibreglass installations and eight custom concrete builds across Gauteng, and Cosmo took National Pool of the Year for fibreglass in 2025.
That matters when you are choosing, because it means the recommendation you get from us is not a function of what we happen to sell.
Frequently asked questions
Both last decades when they are built properly. A fibreglass shell carries a 10-year structural guarantee and typically holds its surface far longer than a marbelite interior, which is renewed periodically as a matter of course.
Usually, for a comparable size — and noticeably cheaper to run. The gap narrows if you need a size or shape that pushes you to the top of the range.
Our range covers normal domestic depths, including proper deep ends. A custom depth profile, or a depth outside the moulded range, is a concrete job.
Yes. Custom concrete pools are a core part of what we build, and we will quote one for the same brief as the fibreglass option so you can compare properly.
That is a third option worth weighing up: relining gives an existing pool a new interior without rebuilding it, in either fibreglass or marbelite.
Compare both for your own garden
Price a fibreglass shell instantly, or talk to us about a custom concrete build.