<img height="1" width="1" style="display:none" src="https://www.facebook.com/tr?id=2312617572090101&amp;ev=PageView&amp;noscript=1">

Common Fiberglass Pool Problems And Their Solutions

While we would love to tell you that owning a pool is all sunshine and rainbows, the truth is that it’s not. Like with any other major investment, there are possible problems that you may encounter and it’s important for you to be aware of these problems before you fully commit to purchasing a pool.

Now, our intention is not to scare you with these problems, but you need to be aware of what you may encounter in the future. And we won’t just tell you what to look out for and say, “Good luck, you’re on your own!” We’ll tell you how you can deal with these problems and potentially avoid them with proper care for your pool.

1. Colored Surface Repairs


The Problem

The standard white or blue gelcoat has become just that—the standard. And for many people, the standard isn’t fun anymore. They want something different, something that stands out! They want what they see on the internet or at their friends’ houses bold, sparkling colors.

Therefore, colored/sparkled gelcoats have become more and more common. And although this provides a different look than the standard gelcoat, there are some problems that could arise when it comes to future repairs on a colored/ sparkled gelcoat.

If you need to repair the surface of a pool that has a colored gelcoat other than white or blue, it can be difficult to find materials that match the factory finish exactly.

The Solution

We should point out that most fiberglass pools that are well-cared for don’t need repairs in the first 20-40 years, which is a good chunk of time. So, this is something that won’t pop up for a while.

But, when it does, the type of gelcoat finish that you choose has a significant impact on how the repairs will turn out.

If you choose a colored gelcoat finish, keep in mind that they are applied in multiple layers that can consist of a solid color, metallic flake, and clear coat. They overlap each other to create the completed finish, but this process can only be done during the manufacturing process.

Therefore, re-finishing the gelcoat in the same manner is impossible but can come very close to the original factory finish. Then end results will ultimately appear slightly different but should still look great.

However, solid gelcoat finishes such as the standard white and blue allow us to make a factory finish-accurate repair since they are one layer as opposed to multiple. What does this mean? Well, it essentially means that we can duplicate the manufacturing process of the gelcoat and match the factory finish so there are little to no differences in the surface.

2. Spider Cracks in Gelcoat

The Problem

Spider cracks are hairline cracks that only occur through the thin layer of the gelcoat and don’t extend beyond into the entire structure of the pool.

These cracks are a result of pressure on a certain point of the pool shell that the gelcoat’s flexibility cannot withstand or on non cantilevered tops of the pool coping that have been exposed to high heat. It’s highly unlikely that you will have any objects around the gelcoat once your pool is installed, which is why spider cracks are more a result of improper shipping, manufacturing erroror pool builder installation error.


They also tend to be isolated in one small section of the pool and do not affect the entire structure as a whole. So, they don’t cause significant damage that you should be worried about.

These occur through normal wear and tear of the pool and there isn’t really much you can do to prevent them. They are also hard to see with the naked eye, so they don’t disrupt the look of the pool to you or anyone else.

The Solution

Fiberglass pools are known for their durability and strength, but they need to be shipped and installed properly and with care. So, the solution to battle spider cracks is more ours and the manufacturers responsibility than yours. Just as above a surface repair can fix all spider cracks.

3. Bulging Pool Walls

The Problem

During the installation process of a fiberglass pool, we must complete a process called back-filling.

You see, since we dig a hole that is roughly 30 inches larger in diameter than the shell, we must fill the open space between it and the earth.

There are 2 materials we use to fill out the remaining space—clean stone and sand.  While stone is usually the best back fill material because it allows water to flow through it and does not liquefy. Sand is only permitted to be used when the pool is being constructed in a sandy environment.

The main reason as to not use sand in any other environment than its own is sand liquefies when it becomes saturated with water (there is always some sort of ground water around every pool), making it heavier than the water that fills the pool. Therefore, if the pool wall is not strong enough, sand can create so much pressure around the pool that it will bulge the walls.

The Solution

The best thing you can do to prevent wall bulges is to use make sure your contractor will install the pool properly by using clean stone as back fill during the installation process unless in a sandy environment. 

Since stone is a solid and does not have a reaction to water like sand does, it will not become heavier than the water in the pool and therefore won’t cause the wall to cave in.

Not only does it provide a sturdy barrier between the pool and earth where the original hole was dug, but the fiberglass pool shell will be able to hold its own against stone as well.

Keep in mind that stone does increase the overall cost of a fiberglass pool, but we believe that it’s much more worth it than having to fix bulging in the walls.

In addition to using clean stone to back fill around the pool we also recommend that you have some sort of de-watering system installed that allows you to remove ground water from around your swimming pool.

4. Fading and Discoloration of Colored Finishes

The Problem

If a fiberglass pool is not well-maintained, the surface can fade or become discolored over time.

Water chemistry is a key component in the prevention of fading and discoloration and although the surface of fiberglass pools does not directly affect the pH level of the water, you still need to check it regularly.

The Solution

As long as the manufacturer does their part in creating a strong and durable fiberglass pool and you regularly check the water chemistry to make sure it is balanced, fading and discoloration shouldn’t be an issue. Never have too high of a chlorine level and always make sure pH and Alkalinity are in balance.

Cross Lynx Composite Technology is used by manufacturers, including one that we use—River Pools and Spas. For a detailed explanation of how they use this technology, see the video below.


5. Settled Plumbing

The Problem

“Settled plumbing” can be a little misleading, so let us explain.

The plumbing itself actually does not settle—the backfill around the pool shell does.

Yep. We’re back to the discussion of backfill and once again, the issue arises with the use of sand as backfill.

When sand liquefies, it becomes heavier (as we discussed) and sinks into the ground over time. And not only does it sink—it takes the plumbing with it.

Since the sand backfill is used to fill out the entire space between the pool and earth, it must encapsulate the plumbing to create a level surface. Therefore, when the sand sinks, the plumbing sinks since it is engulfed by the sand.

The Solution

Using gravel as backfill will prevent settling of the plumbing of a fiberglass pool. Gravel itself will not settle, so in turn, the plumbing won’t either.

Like we said earlier though, it does increase the overall cost but using gravel will save a plumbing mess in the future.

Final Thoughts

As you can see, fiberglass pools may have their own problems just like any other type of pool. But the nice thing is, each problem has a solution.

  • You can use a solid surface finish to avoid repairs that a colored surface would need.
  • Spider cracks can be prevented by taking precautionary measures and being careful with the pool shell.
  • Wall bulges can be prevented by using gravel backfill instead of sand.
  • Fading and discoloration of colored finishes can be prevented by maintaining water chemistry and caring for the pool regularly.
  • Plumbing settling can be avoided by using gravel backfill instead of sand.

We hope that this information has given you more insight into the problems that may arise with fiberglass pools and how you can solve them.

Each type of pool has their own potential problems. That’s just something we all have to accept. There’s really no way around it. But what you can do is continue learning about each pool’s problems and solutions in the articles listed below.