In this article
A pool is a system of many parts: a concrete shell, waterproofing, tiles and grout, fittings in walls and floor, a buried pipe network and equipment in a plant room. A leak can come from any of them, and each part has its own causes and fixes. Many repairs fail because they treat the symptom in one place while the cause is somewhere else.
This article is organised by leak location: common causes in each part and how to fix each one permanently rather than temporarily, followed by steps to prevent recurrence. The title mentions Riyadh, where most of our projects are, but these causes apply to pools across Saudi Arabia.
How to know your pool is really leaking
In hot, dry weather some water evaporates daily, especially with wind and water features. A leak has distinct signs:
- Loss greater than evaporation explains, continuing on calm, cooler days.
- A bucket test shows the pool losing more than a bucket in the same conditions.
- More chemicals are needed because fresh water is constantly added.
- Damp or sinking appears around the pool or in the plant room.
- You notice cracks, hollow tiles or open grout.
For more, see pool leak vs natural evaporation.
Leak causes by location
Concrete shell
- Cracks from soil settlement or movement.
- Untreated construction joints.
- Rusting rebar cracking concrete from inside.
Waterproofing
- Ageing material that has lost flexibility.
- Thin application or poor surface preparation.
- No reinforcement at corners and fittings.
Tiles and grout
- Grout eroded by unbalanced water.
- Loose tiles letting water reach the membrane.
Fittings
- Cracked sealant around lights, returns and skimmers.
- Worn gaskets and rings in light fittings.
- A cracked skimmer body or one separated from the concrete.
Buried pipes
- Joints separated or hardened by soil movement.
- Breaks from excess pressure or tree roots.
Equipment and plant room
- A failed pump shaft seal.
- Filter lid, valves or exposed joints.
Engineering leak detection steps
- Bucket test with pump on and off.
- Note the level at which loss stops.
- Inspect the plant room and exposed joints.
- Dye-test fittings and cracks.
- Pressure-test each pipe line separately.
- Use listening devices and cameras where needed.
This order starts simple and rules out possibilities one by one, so nothing is broken out or drained until the source is known.
The lasting fix for each cause
| Leak location | Common temporary fix | Lasting fix |
|---|---|---|
| Structural crack | Sealing over the tile | Treat the cause, open and inject the crack, re-waterproof around it, fill test |
| Aged waterproofing | Repeated local patches | Full re-waterproofing with a flexible multi-coat system |
| Grout and tiles | Surface grout filling | Remove failed grout, check membrane behind, regrout with a suitable product |
| Fittings | Silicone around the part | New gaskets and rings, proper resealing, a sealing collar if missing |
| Buried pipes | Sealant added to the water | Precise location, limited excavation, replace the damaged section, pressure test |
| Equipment | Tightening joints | Replace seals and parts, correct system pressure, shade exposed joints |
Three common cases where the real cause is missed
Plant room damp that looks like a pool leak
The owner sees water on the plant room floor and assumes the pool shell leaks. Inspection shows a failed pump seal or loose filter lid. The fix is simple and unrelated to the shell, but without testing someone might propose unnecessary waterproofing.
A visible tile crack and a pipe leak
A hairline floor crack is repaired, yet the loss continues. The real leak is in a buried return line, and the crack was superficial. A pipe pressure test before the repair would have saved draining and time.
Fixing the light and missing a second source
Older pools may have more than one source. Sealing a light niche reduces the loss but does not stop it because a second leak exists in grout or another line. That is why we retest after every repair.
Confirming the repair worked
- Fill test before tiling if waterproofing was involved.
- Repeat pressure tests on repaired pipes.
- Monitor the level for several days alongside a bucket test.
- Give the owner a report of the work and what the warranty covers.
Preventing leaks from coming back
- Balanced chemistry: pH roughly 7.2 to 7.6, with hardness and alkalinity monitored.
- Level monitoring: a mark on the tile helps you spot change early.
- Regular checks of fittings and grout, especially after summer.
- No excess pressure: do not fit an oversized pump without checking the pipes.
- Protect the surroundings: direct irrigation and rain away and avoid deep-rooted trees near pipe routes.
- Maintenance contract: regular visits catch small problems early.
YAM Pools finds the leak source first, then treats the cause rather than the symptom, with testing of the result, a written quotation and a written warranty on workmanship and waterproofing. We serve Riyadh and all cities of Saudi Arabia.
Frequently asked questions
What are the most common causes of pool leaks?
Fittings such as lights and returns, eroded grout and buried pipes are among the causes we see most. Every pool still needs testing to find its own cause.
Do leak sealers added to the water work?
They may help briefly with very small leaks, but they do not fix a structural crack or broken pipe and can make detection harder later. We do not recommend relying on them.
Can a pool have more than one leak source?
Yes, especially older pools. We continue testing after finding the first source and confirm with tests after repair.
How long should I monitor the level after a repair?
Several days with a bucket test for comparison. If pool loss is close to bucket loss, the repair worked.
