Swimming Pool Leak Detection in Bracknell

Symptoms

A property in SL4 housing a school swimming pool required further investigation and repair work following a previous visit that had identified a failing skimmer pipework line. The skimmer pipework had already been shown to be unable to hold pressure, and the return valves in the filtration room had also been identified as needing replacement.

The scope of work across three days covered the pool surround, underground pipework, skimmer pots, and the filtration room.

Methods Used

The swimming pool leak detection work began with pressure testing the skimmer pipework to confirm the known failure before using acoustic listening equipment to identify the loudest echo point along the line. Tracer gas was then deployed to confirm the location, directing excavation to the correct area without unnecessary disruption.

As the dig progressed and the fault became more complex than a simple pipe crack, the investigation adapted — additional pipe sections were tested once the damaged section was removed, and a hydrophone was used to listen to the pool water for any remaining acoustic evidence of leaks once repairs were underway. Dye testing was also applied to the skimmer frames after fresh water was observed entering the excavated hole during refill, identifying draw-through at the skimmer shrew holes.

Investigation Process

1. 1
   Pressure test and acoustic survey

   The skimmer pipework was plugged and pressurised, confirming it could not hold pressure as previously found. Acoustic listening equipment was used to identify the loudest echo point, locating it close to the skimmer pot.

2. 2
   Tracer gas confirmation

   Tracer gas was introduced into the pipework and detected at the surface, confirming the leak location adjacent to the skimmer pot before any excavation began.

3. 3
   Initial excavation and tile removal

   A small section of tiles next to the skimmer was removed and the ground excavated to approximately 800mm, where the pipework was found. Further tiles were removed to improve access, and tracer gas confirmed the leak was on the underside of the skimmer.

4. 4
   Excavation extended, fault identified

   The hole was extended on both sides of the skimmer pot surround. The leak was traced to a T fitting connected directly to the skimmer pot, and it was determined that a repair in place was not feasible — significant excavation or skimmer pot renewal would be required.

5. 5
   Customer advised, bypass agreed

   The customer was advised that the skimmer pot should be plugged and the pipework rerouted to bypass it, allowing the pool to remain operational using the remaining skimmer and the low-level side suction. The customer agreed to this approach.

6. 6
   Pipe cut and skimmer bypassed

   When the existing pipework was cut, the pipe connection at the leaking joint sheared completely, consistent with the pipe having become brittle over time and with ground movement having caused the break. The section was removed and the skimmer pot bypassed.

7. 7
   Remaining pipework pressure tested

   With the damaged section removed, the pipework back to the plant room and the second skimmer were both pressure tested and held, confirming no further leaks on the skimmer line.

8. 8
   Pool refill, dye test, and hydrophone check

   As the pool refilled, fresh water was seen entering the excavation hole. Dye testing of the skimmer frames showed dye being drawn into the shrew holes; these were plugged with epoxy sealant. A hydrophone was used to listen to the pool, which was now quiet with no further evidence of leaks.

9. 9
   Filtration room valve replacements

   The two return outlet valves were cut out and replaced with new valves after the outlets were bunged. The skimmer line valve was also replaced. A dripping union glued directly into an elbow with no cuttable pipe was treated with a specialist epoxy material, which was left to cure for six hours before filtration was restored.

10. 10
    Pool level check and skimmer pot repairs

    On Day 3 the pool was found to have had no observable water loss overnight. Both skimmer pots were inspected and found to have multiple cracks; all cracks were repaired with epoxy, and all joints around the skimmer throats and between the pots and throats were also sealed with epoxy as a precaution.

Result & Outcome

The leak was located on a T fitting on the underside of the skimmer pot, approximately 800mm below the pool surround. The fitting had failed and the connected pipework had become so brittle that the joint sheared completely when cut, indicating long-term deterioration and likely ground movement as contributing factors. The skimmer was bypassed and the pool confirmed operational with the remaining skimmer and low-level side suction.

Once the primary leak was resolved, additional work was completed across the filtration room — three valves replaced, a dripping union sealed with specialist epoxy — and both skimmer pots were patched with epoxy after multiple cracks were identified on visual inspection. A hydrophone confirmed the pool was quiet following all poolside repairs, and no water loss was observed overnight before Day 3 work began.

For a swimming pool leak detection job of this complexity, the outcome is a functional pool with the immediate faults resolved. However, both skimmer pots are visibly brittle and cracked; the engineer has recommended that both be replaced in the near future along with the brittle skimmer pipework, and the customer should continue to monitor the pool in the interim.