How to Patch a Pool with Water in it

Aquaman Leak Detection Blog

Why Is My Pool Leaking? Top Causes of In-Ground Pool Leaks

On Nov 30, 2023

Aquaman Leak Detection - Why is My Pool Leaking Top Cause of In-Ground Pool Leaks

When identifying and fixing a leak in an in-ground pool, the first step is to locate the problem area. Unfortunately, this can be one of the toughest parts of the process! Common places for water to leak are along seam orientations, around skimmers and light niches, on the sides or even beneath the coping stones, or through cracks in concrete surfaces if your pool is installed on a slab. 

There are many reasons for leaks in swimming pools.
  • Pumps and motor problems can cause a swimming pool leak.
  • General wear and tear on the pool surface can cause leaks.
  • Broken plumbing beneath the pool deck can saturate the ground.
  • Loose fittings on railings, tiles, and other accessories lead to leaks.

These problems also apply to slab leaks, spa tubs, and other in-ground water features.

It may be more difficult to find a leak in an in-ground pool, but the leak must be repaired to avoid ground saturation, flooding, and water waste. Depending on the type of in-ground pool, there will be different risk factors for leaks.

Fiberglass Pool Leaks

This type of pool or spa tub can last for 25 years or more without problems. Fiberglass in-ground pools and hot tubs are pre-fabricated shells that are placed in a hole prepared for their size. They should be set in gravel, although many fiberglass pools are backfilled with sand.

Cracks and leaks can occur in the plumbing when the surrounding sand becomes saturated or it settles. Finding plumbing leaks is not easy since the intake and return lines are under the pool decking.

Fiberglass pools may also have fissures in the gelcoat surface from improper handling and installation. These cracks should be repaired and repainted to keep the fissures from spreading and causing leaks.

The pool must remain full to maintain enough pressure to keep the surrounding ground from pushing a bulge into the fiberglass shell. This can happen when the ground is wet from rain or a leak.

Vinyl Pool Leaks

Tears in the vinyl lining are a major cause of swimming pool leaks in this type of surface. Sharp objects hitting the side of the pool or a careless swimmer can cause a tear in the vinyl surface.

Vinyl tears are easy to patch but they must be treated immediately to stop the leak from spreading.

Concrete Pool Leaks

Many in-ground swimming pools in Florida are concrete or gunite, the gravel and concrete composite. These are the most durable pools with a lifespan of decades.

A crack or fissure in the pool's surface must be repaired immediately. This type of crack can come from age or sharp objects hitting the side of the pool. Decorative tiles can become detached from the surface. Railings, the skimmer pad, and other fittings can also become loose.

The repair may be as simple as injecting a flexible polymer adhesive into a swimming pool leak. This can be applied while the pool is filled.

Pumps and Plumbing

Underground leaks can be caused by corrosion or movements in the ground. PVC pipes can be easily repaired unless damage is extensive. Then they have to be replaced.

When trying to determine the cause of a decreasing water level in a swimming pool, it is important to make sure that the skimmer valve is closed. If this does not stop the water from dropping, then the risk of pump damage should be considered and a submersible pump should be used instead. If this still does not resolve the issue, it is likely that there is a leak somewhere else in the system; therefore, a leak detection dye test can be done when the water stabilizes at any particular level. To locate where the leak may be coming from, careful inspection should be made during this time, as it could be coming from any number of places such as small openings or cracks in the pool walls or piping. Small debris which gets sucked into these tiny voids can often provide an indication of where a potential leak may be happening. With knowledge of locations and signs to look out for during inspections, leaks can more easily be identified and solved.

Questions to Consider When Pinpointing an Indoor Swimming Pool Leak

Is the Pool Leaking Only With the Equipment On?

Leaking on the pressure side of the plumbing, (after the pump) can cause much more noticeable leakage than dripping on the suction side does. If you notice any water consistently running out of the waste or backwash line, your pool may be leaking.

On the other hand, if there are no obvious sources of leakage while the filter pump is on, you may need to inspect parts of your pool that may not be under pressure where small drips can become full-blown gushers without being noticed until it's too late. It's best to check areas downhill from your pool for weepers where underground leakage may be surfacing near your foundation or anywhere else outside your pool area. 

Is the Pool Leaking Only With the Equipment Off?

If the pool leaks when the equipment is off this could mean that there is an issue with the suction side of your pool plumbing. With the filter pump on, this can create a vacuum in pipes leading from the pool to the pump. It’s possible that the air entering through these pipes is coming from elsewhere, like a small crack or a broken seal. If this is the case, you may notice air getting trapped in your pump basket with a clear lid, bubbling out of your return lines, or building up inside your filter tank.

Does the Pool Leak All the Time?

The most common reason inground pools leak is due to holes or cracks in the pool’s shell. This makes it essential to conduct a thorough pool leak detection process to identify any weaknesses or fractures that could be making the pool vulnerable to leakage. Careful examination of the tile line, plaster, and vinyl should be done, as well as inspecting inside the skimmer(s). A common problem with leaks is where there is a separation between the plastic skimmer and the concrete pool. Fortunately, this type of leak is usually straightforward to fix.

It's also helpful to perform a dye test - when the pump is turned off and the water remains still, place a bit of dye near any suspicious cracks and holes and observe if it travels somewhere, which would indicate a leak. By taking all these steps into account during a pool leak detection process, one can gain insight into whether or not their pool may have been leaking for some time.

Are There Leaks at the Equipment Pad?

The first step in finding an equipment pad leak is to look closely at the filter, pump, heater, and valves on the pad. It is important to make sure all these components are secured properly and not leaking. Visual inspection may help identify any loose components or build-up of calcium deposits from hard water that could cause a small drip.

Secondly, checking for moisture around the ground surrounding the equipment pad may indicate a leak which might have pooled around the equipment pad’s base plate seal. If this is found then it’s essential to take further steps as it could lead to corrosion of additional parts resulting in higher leakage over time. 

The Experts at Aquaman Leak Detection Can Help!

Aquaman Leak Detection uses sophisticated sonar equipment to find and fix a swimming pool leak from plumbing lines under the decking. The entire deck does not have to be torn up to repair a return line leak.

Check the suction lines that carry water to the filter, heater, and chlorinator for leaks. This system starts at the skimmer that is designed to keep the piping free of debris.

Pumps should also be checked for wear in the system. A new impeller or hose may be necessary.

Aquaman Leak Detection offermodern technology to find and repair leaks. Our service includes our warranty. Contact us with any questions if you suspect your swimming pool is leaking.


The Complete Guide to Swimming Pool Ownership


By Aquaman

We now proudly serve all of Florida. Each of our trained and certified pool leak detection specialists utilize the most advanced methods and technologies.

Blog Comments