Renovating an Old Pool: Leaks and Finishes

Renovating an old pool does not start with new tiles. First find where it leaks, assess the shell and check the equipment, then decide how far the restoration should go.

People who buy a house often find a pool in the garden that has not been used for years: mosaic tiles falling off, water dropping every week, a noisy pump. The first instinct is usually to replace the finish and get the pool running quickly. But visible defects are often the result of deeper problems. New mosaic laid without fixing a leak can come away in the same places after a season or two. That is why restoring an old pool starts with diagnosis.

Checking whether it leaks

A pool always loses water through evaporation, and on hot, windy days the drop is noticeable. A simple way to separate a leak from evaporation is the bucket test: a bucket of water is placed on a pool step, and the levels in the bucket and the pool are marked at the same time. If after a day or two the pool level has dropped much more than the bucket level, a leak is likely.

The next step is to narrow down where it is:

compare the level drop with the pump running and switched off; a difference can point to the pipework;
if the level stops at a certain point, for example below the skimmer mouth, the leak is in an element at that height;
dye is used around wall cracks, light housings and fitting joints to see which way water flows;
pipes are pressure-tested, or acoustic equipment is used to pinpoint the leak.

Damp patches in the plant room or garden, sinking paving or a strip of grass that stays green all the time can also signal a hidden pipe leak.

Assessing the shell

Check groundwater first: where it is high, an emptied pool can literally float out of the ground. Once drained, the walls and floor are inspected carefully. Hairline surface cracks and structural cracks need different approaches: the former are usually dealt with by renewing the layer under the finish, while the latter are repaired only after a specialist has established the cause, whether ground settlement, reinforcement corrosion or frost damage.

Rust stains and spalling on concrete can indicate corroding reinforcement. Such areas are opened up, the rust is cleaned off, the steel is protected and the concrete is restored with a dedicated repair mortar. Painting over the problem only postpones it.

Waterproofing and a new finish

Once the shell is repaired, the waterproofing layer is rebuilt. Whether the old finish must be removed entirely depends on how well it is bonded: laying a new layer over hollow-sounding tiles is risky. Several options are considered for the new finish:

mosaic or ceramic tiles: long-lasting, but joint quality is decisive;
reinforced PVC membrane: quickly creates a watertight surface in an old shell prone to cracking;
specialist pool paints: a fast solution but one that needs renewing more often.

Whatever finish is chosen, the pool is filled only after all layers have cured and the manufacturer's waiting time has passed.

Updating the equipment

In old pools the equipment is often worn out or was never sized for the pool in the first place. A noisy pump, a filter that clogs constantly or water that never clears may mean the system needs to be recalculated. During renovation the following are checked:

whether pump capacity and running schedule match the pool volume;
the filter type and the condition of the filter media;
whether valves and fittings are leaking;
whether it makes sense to modernise disinfection, for example by switching to salt electrolysis;
whether old halogen lights can be replaced with low-voltage LED fittings.

The electrical panel, earthing and residual current protection must be checked. In older systems, electrical safety may not meet current requirements.

Surroundings and safety

Coping stones, steps and handrails are part of the renovation too. A loose coping stone can fall into the water or injure someone. Slippery old tiles are particularly dangerous when wet. For families with children, fencing and covers are worth rethinking at this stage.

Short renovation sequence

Test for a leak and locate it.
Drain the pool after checking the groundwater risk.
Establish the cause of any cracks and repair the shell.
Pressure-test the pipework and replace it if needed.
Install waterproofing and the new finish.
Update the equipment and electrics.
Fill the pool, start the system and monitor the level for several days.

Pool renovation at Zaferoğlu İnşaat begins with an assessment of the existing structure, and pool projects have their own section in the company's portfolio. Measure how much water the pool loses a day with a bucket test; that figure says a lot about where the restoration should begin.

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