Swimming Pool Leak Detection in Broadstairs

Symptoms

The owner of a property in CT10 reported that the swimming pool was losing up to 20cm of water per day, a rate significant enough to prompt an investigation into the pool's pipework, liner, and associated equipment. A local pool company had already attended and confirmed that the pipework appeared sound, but the water loss continued.

When left to settle without any pump assistance, the water level dropped to just below the bottom of the lowest step, providing a clear indication of where at least one source of water loss was situated.

On arrival, the pool was running on the sump line only, with the skimmer isolated at the suction manifold — a precautionary measure given the uncertainty about where the leak or leaks were originating. The scale of the daily water loss and the specific level at which the pool stabilised pointed toward multiple potential sources, including the liner, the skimmer line, and the fittings around the pool light.

A full swimming pool leak detection inspection was commissioned to identify all active leak points, test the integrity of each pipework circuit, and assess the condition of the liner throughout the pool.

Methods Used

The swimming pool leak detection investigation was structured to test each pipework circuit individually before moving on to the liner and fittings. Pressure testing was applied to the sump, return, and skimmer pipework in sequence.

Where pressure was lost, acoustic and tracer gas methods were deployed to narrow down the leak location. Once the pipework circuits had been assessed, attention turned to the liner itself, where acoustic and leak tracking equipment was used to identify areas of concern before a physical in-pool inspection was carried out and dye testing was used to confirm active ingress points.

The combination of pressure testing, acoustic correlation, tracer gas, and dye testing allowed each suspected area to be either cleared or confirmed systematically. This approach ensured that all active leak points were identified rather than addressing only the most obvious source of water loss.

Investigation Process

1. 1
   Pool condition assessed on arrival

   The pool was found running on the sump line only, with the skimmer isolated at the suction manifold. The water level and operating configuration were noted before testing began.

2. 2
   Sump pipework pressure tested

   The sump pipework was pressurised to 15psi and held pressure for 20 minutes with no measurable loss, confirming it to be sound at the time of testing.

3. 3
   Return pipework pressure tested

   The return pipework was pressurised to 15psi and similarly held pressure for 20 minutes with no measurable loss, clearing it as a source of water loss.

4. 4
   Skimmer pipework pressure tested — failed

   The skimmer circuit was pressurised and failed to hold pressure, confirming an active leak on the skimmer pipework and requiring further location work.

5. 5
   Acoustic equipment deployed on skimmer line

   Acoustic listening equipment was used to detect the leak signature underground, with the loudest echoes recorded in the ground in front of the filtration equipment.

6. 6
   Tracer gas introduced to skimmer pipework

   Tracer gas was added to the skimmer circuit and the area walked with gas analysers; escaping gas was detected at the concrete slab of the filtration shed close to where the pipe entered it.

7. 7
   Liner inspected with acoustic and tracking equipment

   Acoustic and leak tracking equipment was used across the pool liner, identifying two areas of concern in the deep end for physical follow-up.

8. 8
   In-pool inspection carried out — tears identified

   A physical inspection of the two flagged areas revealed a large L-shaped tear with each leg approximately 70mm long, and a second tear where the liner had moved and separated from its fixing beneath the light frame, leaving a visible gap.

9. 9
   Dye testing confirmed active ingress at both liner sites

   Dye was applied at each liner defect and observed to be drawn in behind the liner at both locations, confirming both as active sources of water loss.

10. 10
    Temporary patch repairs carried out with customer consent

    With the customer's agreement, a vinyl patch was applied over the L-shaped tear and clear construction sealant was applied under the light frame. Both repairs were explained to the customer as temporary measures only.

11. 11
    Pump left running on sump only

    The pump was primed and left running on the sump line with the skimmer valve closed at the suction manifold, as the skimmer leak location under the slab made immediate repair impractical.

Result & Outcome

Three active leak points were identified across this swimming pool leak detection inspection. The skimmer pipework failed its pressure test and tracer gas analysis pinpointed the leak to the concrete slab of the filtration shed, at the point where the skimmer pipe enters the slab. The sump and return circuits both held pressure throughout testing and were cleared. Within the pool itself, two liner defects were confirmed: a large L-shaped tear in the deep end with each leg measuring approximately 70mm, and a second failure beneath the light frame where the liner had moved away from its fixing, leaving an open gap. Dye testing at both sites confirmed water was actively passing behind the liner at each location.

Temporary repairs were completed on both liner defects with customer consent — a vinyl patch over the L-shaped tear and clear construction sealant under the light frame. These cannot be considered permanent; any further movement in the liner may cause either repair to fail, and the pool reaching its normal operating temperature will cause liner movement that could open additional defects. A specialist liner or pool installation company should be engaged to assess whether the liner requires a professional repair or replacement.

The skimmer leak under the filtration shed slab will require further access work to repair. Options include removing the pump and suction manifold and excavating the base slab, or tracing where the pipe exits the slab and re-routing a short section above ground within the filtration shed. With the skimmer valve closed at the suction manifold, the pool can continue to operate on the sump line. If further water loss is observed with the valve closed, the skimmer pot should be plugged as an interim measure until the pipe can be accessed and repaired.