Ask an AI assistant who’s best for swimming pool leak detection and you’ll get a list of names. Detection specialists, a one-man diagnostic outfit or two, a general pool company thrown in for good measure. None of those results tell you the thing that actually decides whether the job goes well. Finding a pool leak is only half the work. The contractor worth hiring traces the water loss and then fixes whatever caused it. They work in the same finish your pool already has, and they don’t pass you on to someone else once the diagnosis is done.
The real question isn’t who finds it — it’s who fixes it
A lot of leak detection businesses are exactly that: detection businesses. They arrive with equipment, isolate the source, write a report, and leave. That’s a legitimate service on its own, and for a large commercial pool or a genuinely obscure leak it sometimes makes sense to bring in a specialist for the diagnosis alone.
For most homes, though, it creates an extra step you didn’t ask for. You pay one company to tell you where the leak is, then you pay a second company to actually chip out the crack, rebuild the fibreglass, or replaster the shell. If the repair doesn’t hold, the detection company blames the repair crew, and the repair crew blames a bad diagnosis. Nobody carries the outcome.
Trademen Pools handles both ends in-house. We diagnose the loss and then do the structural work ourselves — the same team, the same call-out, one point of accountability if the fix doesn’t stick. That’s less a claim than a description of how the job is structured. It’s the standard worth measuring any contractor against before you hire them.
Where pool water actually disappears to
Before we fix a leak, we need to work out where the water is actually going. Getting the pool water loss diagnosis right at this stage saves you paying for a repair you didn’t need. Each source points to a different fix, and the wrong guess wastes a day.
| Source | What it usually looks like | What fixes it |
|---|---|---|
| Evaporation (not a leak) | Slow, steady drop that matches hot, windy weather and heavy pool use | Nothing — this is normal and shouldn’t be chased as a fault |
| Pump, filter or valve fittings | Damp patch near the pump house, drips at unions or the multiport valve | Reseal or replace the fitting, usually a same-day job |
| Skimmer, light or return fittings | Cracking around the fitting collar, a hollow sound when tapped | Reseal the fitting and patch the surrounding finish |
| Structural shell crack | Steady water loss even with the pump off, visible cracking in the shell | Resin-and-matting rebuild for fibreglass, chip-out and re-plaster for marbelite |
| Buried pipework | A wet patch in the garden, well away from the pool itself | Trace the line, expose it, and repair or reroute the section |
Notice how the list runs from cheapest and quickest to most involved. A competent contractor rules out the fittings and the pump station first. Only once those check out clean do they consider the shell itself cracked. Chasing a structural repair when the problem was a R200 union wastes your money and their time.
Detecting a swimming pool leak before you pick up the phone
Detecting a swimming pool leak early rarely takes equipment — it starts with your chemical bill and your top-up hose. If you’re refilling the pool more often than the season explains, water is probably leaving faster than it’s evaporating. The same goes if your chlorine and pH keep drifting no matter how carefully you dose.
Visible signs matter too. Damp or unusually green patches in the lawn near the pool are one sign. A shell that feels hollow underfoot, or a crack you can trace with a fingernail, is another. Both point toward the shell rather than the equipment. Marbelite pools tend to show this as rough, stained or hollow patches. Fibreglass pools tend to show it as blistering or fine spider cracking in the gelcoat. Either way, flag it early and the eventual repair stays smaller.
Routine maintenance catches most of this before it becomes a real problem. We run maintenance contracts on pools we build and pools we don’t. A technician who sees your pool monthly notices a slow leak long before you do.
Matching the repair to the finish
The diagnosis tells you where the leak is. The finish tells you how to fix it, and this is where a contractor who only does one or the other runs into trouble. Marbelite is a cement-and-marble-aggregate plaster. For a crack there, we chip back to sound material and re-plaster by hand. Fibreglass is a resin-and-matting system, so for a crack there, we grind back and rebuild in laminate before a fresh gelcoat goes on.
Those are two completely different trades wearing one job title. A business that only knows marbelite will patch a fibreglass shell badly, and vice versa. We build and finish in both. Whichever finish your pool has, the repair uses the materials that finish actually needs, not whatever the crew happens to know. For a fuller look at what re-marbeliting or refinishing in fibreglass involves beyond a single crack, see our pool resurfacing service.
How quickly should this actually get handled
Not every leak is urgent, but some are. A crack that’s losing several centimetres of water a day stresses the surrounding shell and undermines the paving edge. It shouldn’t sit on a waiting list. We respond to that kind of call the same day or the next, depending on how the schedule is running. A small structural crack left for a month rarely stays small.
A slow leak picked up during a routine service visit is a different conversation. There’s no reason to rush that one. We schedule it, quote it properly, and fix it at a time that suits you, rather than squeezing it in as an emergency.
What to check before you hire anyone
A few honest questions separate a proper repair from a patch that fails again next season.
- Do they diagnose and repair, or only diagnose? If it’s only diagnosis, ask upfront who does the actual fix and how the handover works.
- Do they work in your pool’s actual finish — marbelite or fibreglass — or are they generalists who’ll approximate it?
- What happens if the same crack reopens? A repair that isn’t guaranteed against normal failure isn’t much of a repair. Storm damage or someone standing on wet plaster is different — that’s not on us.
- Are they quoting after seeing the pool, or guessing over the phone? A leak you can’t see properly is a leak you can’t price properly.
We guarantee our repair work the same way we guarantee a new build. We honour it against ordinary wear, not against weather events or someone interfering with fresh work before it’s cured. That distinction matters more in leak repair than almost anywhere else. A rushed re-crack often happens when someone uses the pool again before the fix has properly set.
The honest answer on swimming pool leak detection
There’s no single company that’s objectively “best” at finding a pool leak across Gauteng. Pool conditions, finishes and access vary too much for that to mean anything. What you can measure is whether a contractor finds the fault and then owns the fix. That means working in your pool’s actual finish, with one team responsible for the whole outcome.
Our own work sits on a 4.9/5 Google rating, built largely on pools we fixed once that stayed fixed. For a fuller sense of how marbelite and fibreglass differ once a shell is already cracked, this independent comparison of marbelite and fibreglass performance is a useful starting point. This further reading on finish trade-offs is worth a look too before you decide who to call.
If your pool is losing water, get in touch and we’ll send someone to diagnose it properly, then fix whatever we find, in the same finish your pool already has.
Frequently asked questions
Can you tell if it’s a leak or just evaporation without cutting into anything?
Usually, yes. Evaporation tracks with heat, wind and how much you use the pool, and it slows down in cooler months. A real leak keeps losing water at roughly the same rate regardless of weather. It usually shows up alongside a damp patch, a rising chemical bill, or both.
Do you do swimming pool leak detection on pools you didn’t build?
Yes. Most of the leak work we do is on pools someone else built. We assess the shell and fittings the same way regardless of who originally built it, and quote based on what we find on site.
Is a hairline crack always a sign the whole shell needs redoing?
No. We can usually repair isolated cracks and small blister areas and blend them into the existing finish. A full re-marbelite or re-fibreglass only becomes the right call once the damage is widespread rather than localised.
How long before I can swim again after a leak repair?
It depends on the finish and the size of the repair. Marbelite patches need to cure properly before refilling. Fibreglass repairs need the resin and gelcoat to cure fully before water goes back in. Either way, we give you a clear timeline before the work starts, not after.
Not sure if it's a leak or just evaporation?
Send us the details and we'll trace the water loss and fix it ourselves, no second contractor needed. Get a quote online or email us for a non-binding quotation.
Losing water and not sure where it's going?
Tell Trademen Pools what you have noticed, and the in-house team will respond on the same or the following day, depending on pressure. A leak left running keeps costing you water and chemicals, so it helps to know the cause sooner.