At some point in your research, you’ve probably seen someone mention a “problem” with fiberglass pools.
Maybe it was spider cracks. Maybe it was bulging walls. Maybe it sent you down a bit of a rabbit hole.
Before you get too concerned, it’s worth taking a closer look at what these issues are, how often they happen, and what can be done about them.
What are the most common fiberglass pool problems?
- Mismatched repairs on colored gelcoats
- Spider cracks in the gelcoat
- Pool walls bulging
- Plumbing leaks from settling
Let’s break each one down.
Problem #1: Repairs on Colored Fiberglass Pools
Modern fiberglass pools often come in a variety of colors and finishes. While they look great, if repairs are ever needed, it can be difficult to match some colored finishes with the factory finish.
Even though repairs are uncommon, they can happen due to shipping damage, installation issues, or rare structural concerns.
Solution: Choose a solid surface finish and skilled repair work
Not all finishes are created equal, and this is one of those details that’s easy to overlook until a repair is needed.
Multi-layer finishes, like metallic or flake systems, are designed to create a certain visual effect, but that layered look is difficult to replicate outside of a factory setting. Because of that, repairs on these finishes are more likely to stand out.
Solid surface gelcoats, on the other hand, are applied in a single layer. This makes them much easier to match in the field, leading to more consistent and less noticeable repairs if they’re ever needed.
A well-trained technician also makes a big difference. While most repairs won’t be completely invisible, a skilled pro can make them far less noticeable.
Problem #2: Spider Cracks in Gelcoat
Spider cracks are small, hairline cracks that form in the gelcoat surface. They’re typically cosmetic, not structural, and are often hard to see unless you’re looking for them.
What causes spider cracks?
They usually happen when pressure is placed on the pool shell beyond what the gelcoat can flex.
Common causes include:
- Improper installation (most common)
- Uneven pool base or debris underneath
- Poor manufacturing or gelcoat application
- Shipping or handling issues
Solution: Focus on quality manufacturing and installation
The best way to prevent spider cracks is simple:
- Choose a manufacturer with strong quality control and proper gelcoat application
- Work with an experienced installer who properly prepares and levels the base
If the pool is built well and installed correctly, the risk of spider cracking is very low.
Problem #3: Pool Walls Bulging
If you've talked to enough pool owners or browsed online forums, you might have heard about fiberglass pool walls developing a bulge. This can happen due to the common practice of using sand as backfill.
When sand is used and becomes saturated, it can liquefy and create pressure against the pool walls. In certain conditions, this pressure can exceed the force of the water inside the pool, leading to bulging.
Solution: Use gravel backfill
Gravel is the most reliable way to prevent this issue because it stays stable regardless of conditions. Unlike sand, gravel doesn’t change its properties when it gets wet, which means it won’t shift or create uneven pressure against the pool walls.
It also provides stronger structural support and naturally compacts as it’s placed, helping the pool maintain its shape over time. This becomes especially important in areas with high water tables or soils that tend to hold moisture, where instability is more likely.
A strong pool shell certainly helps, but the material surrounding it plays just as important a role. Using the right backfill can make all the difference in long-term performance.
Problem #4: Plumbing Settling Causes Leaks
In most cases, the plumbing itself isn’t the problem, it’s the material around it. When sand is used as backfill, it can be difficult to fully compact during installation. Yes, we're back to the sand vs. gravel discussion again.
Even when installers take the time to place and saturate it properly, sand can still settle over time. As it shifts, it can pull the plumbing down with it, creating stress on pipes and connections.
That added pressure can eventually lead to leaks.
Solution: Use stable backfill and proper installation techniques
Preventing this issue comes down to stability. Using gravel backfill instead of sand helps keep everything in place, reducing the chance of movement over time.
It’s also important to work with an installer who takes care to properly support and secure the plumbing during installation. When both the backfill and installation are done right, the risk of plumbing-related issues drops significantly.
Should fiberglass pool problems concern you?
Fiberglass pool problems tend to sound more intimidating than they actually are.
While issues like repairs, spider cracks, bulging, or plumbing movement can happen, they’re typically uncommon and often tied to how the pool is manufactured and installed. When those two factors are handled properly, most homeowners never experience these problems at all.
The key takeaway is simple: focus on choosing a quality manufacturer and an experienced installer. When you do that, you’re not just reducing the risk of problems, you’re setting yourself up for a pool that performs well for years to come.
Frequently Asked Questions
What problems can fiberglass pools have?
Fiberglass pools can have issues like visible repairs on certain finishes, spider cracks in the gelcoat, wall bulging, or plumbing leaks. However, these problems are uncommon and are usually tied to manufacturing quality or installation practices.
What causes fiberglass pool walls to bulge?
Wall bulging is usually caused by improper backfill, especially when sand becomes saturated and shifts. This can create pressure against the pool walls. Using gravel backfill helps prevent this issue.
Why do fiberglass pool plumbing leaks happen?
Leaks are often caused by settling backfill material, not the plumbing itself. When sand shifts over time, it can pull on pipes and create stress at connection points. Stable backfill like gravel helps reduce this risk.
How can you avoid fiberglass pool problems?
The best way to avoid issues is to choose a reputable manufacturer and work with an experienced installer. Proper construction and installation significantly reduce the likelihood of problems.
About the Author
When you’re researching fiberglass pools, it doesn’t take long before you come across a few “what if” concerns, cracks, bulging, leaks, and it can be hard to tell what’s worth worrying about and what isn’t.
I’m Cristian Shirilla, Marketing Manager at River Pools and co-owner of a fiberglass pool installation company in Virginia. Through my work in content and behind-the-scenes conversations with homeowners and installers, I’ve seen how quickly small concerns can turn into big questions during the research process.
I wrote this article to bring some clarity to those concerns, what’s real, what’s rare, and what can be avoided altogether. The goal is to help you move forward with a clear understanding of fiberglass pools so you can make a confident, informed decision about your backyard.
From the Manufacturer
At River Pools, we manufacture fiberglass pools, and we also spend a lot of time talking with homeowners who are working through questions and concerns during their research—especially when it comes to potential problems.
Through our work with independent installers and customers across the country, we’ve seen that most fiberglass pool issues are typically tied to how the pool is built and how it’s installed. When both are done correctly, these problems are far less likely to occur.
That’s why we place such a strong emphasis on our manufacturing process, from material selection to structural design to consistent quality control, so every pool is built to perform the way it should from day one.
If you’re considering a fiberglass pool and want to explore what it could look like in your backyard, the next step is connecting with a trusted independent installer in your area who can walk you through your options.
Ready to start the conversation?
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