Last updated: August 2026
Direct Answer: Common fiberglass pool problems fall into two categories: installation-phase issues like groundwater, uneven ground preparation, and shell misalignment, and post-installation issues like surface cracks, staining, gelcoat fading, and leaks. Most installation-phase problems are preventable with proper site preparation and an experienced builder, while post-installation issues are best caught early through regular visual inspection.
Fiberglass pools are a popular choice among homeowners in Toronto due to their durability, aesthetic appeal, and low maintenance requirements. However, like all pool types, fiberglass pools can encounter issues over time. Understanding common problems and knowing how to address them can help maintain your pool’s beauty and functionality. Here are some insights from experienced pool builders on common problems and their effective solutions.
Installation-Phase Problems to Watch For
Before getting into problems that can surface after your pool is in use, it’s worth understanding the issues that can arise during the installation itself — since most of these are entirely preventable with proper site preparation and an experienced fiberglass pool installation team in Toronto.
Groundwater Issues
Groundwater issues are a significant concern when installing fiberglass pools. Excessive groundwater can undermine the structural integrity of your pool by causing soil erosion around the installation site. This problem often arises in areas with high water tables or poor drainage systems. During installation, high groundwater levels can create instability, leading to complications such as uneven settling of the pool, misalignment of the pool walls, and increased risk of leaks. After installation, groundwater issues can cause the pool to shift or tilt, leading to long-term structural problems.
Addressing it: A comprehensive drainage system around the pool area — French drains, sump pumps, or perforated pipes — helps direct excess groundwater away from the site. Waterproof barriers placed between the pool shell and surrounding soil add another layer of protection, and proper soil stabilization through compaction ensures a stable foundation before installation begins.
Uneven Ground Preparation
Uneven ground preparation is another common issue that can affect fiberglass pool installation, caused by poor site grading, natural ground undulations, or improper excavation techniques. When the ground isn’t level, it can lead to structural imbalances that affect the pool’s overall stability, as well as water level variations that impact usability and aesthetics.
Addressing it: Accurate ground levelling using laser levels or string lines before installation, combined with professional-grade graders and compactors, results in a uniform surface. Consulting with experienced fiberglass pool builders provides valuable insight into effective ground preparation methods specific to your site.
Incorrect Pool Shell Placement (Misalignment)
One of the key challenges in fiberglass pool installation is ensuring the correct placement of the pool shell. Misalignment can result from improper site preparation or errors in measuring and positioning, often leading to uneven pool walls or an improperly fitted shell. Left unaddressed, this can cause structural weaknesses like cracks or shifts, operational problems like uneven water levels, and visible aesthetic issues.
Addressing it: Accurate pre-installation measurements using laser levels and precise measuring tools confirm correct shell placement before excavation. During installation, alignment markers and reference points guide correct positioning, ensuring the shell is level and centred within the excavation area.
Poor Backfilling Techniques
Backfilling — filling the space between the pool shell and the surrounding excavation — is a critical step that ensures the area around the shell is uniformly supported and stable. Inadequate or uneven backfilling can cause the pool to shift or settle unevenly, resulting in structural damage such as cracks or misalignment, along with drainage issues that can erode soil around the foundation.
Addressing it: High-quality, well-compacted materials — typically clean, granular options like crushed stone or gravel — provide good drainage and stability. A layering technique, where backfill is added in thin, even layers and compacted thoroughly before the next layer, ensures uniform support. Backfill material should stay free of organic matter, debris, or large soil clumps, which can cause uneven compaction.
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12 Post-Installation Fiberglass Pool Problems and Their Solutions
1. Surface Cracks
Surface cracks in fiberglass pools can be alarming for homeowners. These cracks are often caused by structural stress, improper installation, or natural wear and tear. While minor cracks may not impact the pool’s functionality immediately, they can worsen over time and affect the pool’s aesthetics and structural integrity.
Tips from Pool Builders: Conduct regular visual inspections to detect cracks early, looking for small fissures or spider cracks. Address minor cracks promptly using appropriate repair kits designed for fiberglass pools. For significant cracks, hire professional pool builders who specialize in fiberglass pool repair to ensure the cracks are fixed correctly.
2. Staining and Discolouration
Staining and discolouration are common issues in fiberglass pools, often caused by chemicals, metals, or organic matter. These stains can make the pool look unattractive and may even indicate underlying water chemistry problems.
Tips from Pool Builders: Maintain a consistent cleaning schedule to remove debris and prevent staining, brushing the pool walls and vacuuming the floor regularly. Ensure balanced pool chemistry to avoid staining. For persistent stains, use specialized stain removers or consult a swimming pool company for professional cleaning services.
3. Gel Coat Fading
The gelcoat is the outermost layer of the fiberglass pool, providing a smooth and shiny finish. Over time, exposure to sun and chemicals can cause the gelcoat to fade, diminishing the pool’s appearance.
Tips from Pool Builders: Protect your pool from UV rays by using a pool cover when it’s not in use. Maintain the correct chemical balance and avoid harsh chemicals that accelerate fading. If the gelcoat has significantly faded, professional recoating restores the pool’s original shine.
4. Pool Leaks
Leaks in fiberglass pools can occur due to cracks, plumbing issues, or structural damage. If left untreated, leaks can cause significant water loss and damage to the surrounding area.
Tips from Pool Builders: Use specialized equipment or dyes to detect leaks and regularly inspect for signs of water loss. For complex leaks, seek professional repair services who can accurately diagnose and fix them. Schedule regular maintenance checks to address potential leak sources promptly.
5. Structural Shifting
Structural shifting can occur due to ground movement or improper installation, compromising the pool’s integrity and leading to significant damage.
Tips from Pool Builders: Ensure the ground is properly prepared and compacted before installation to prevent shifting caused by ground movement. Regularly monitor for signs of shifting and address ground movement issues promptly. If you notice structural issues, consult professional pool builders for an assessment and repair recommendations.
6. Plumbing Issues
Fiberglass pools can experience plumbing problems like leaks, blockages, and faulty pipes, which disrupt pool usage and increase maintenance efforts.
Tips from Pool Builders: Conduct routine checks to identify and address plumbing issues early, looking for leaks or reduced water flow. Fix identified problems promptly, replacing worn or damaged pipes and fittings. Hire pool professionals for thorough plumbing inspections and repairs.
7. Osmotic Blistering
Osmotic blistering occurs when water penetrates the fiberglass shell, leading to raised blisters on the pool surface, caused by osmosis where water molecules pass through the gel coat and create pressure pockets.
Tips from Pool Builders: Inspect the pool surface regularly for signs of blistering — early detection prevents extensive damage. Consult professional fiberglass pool builders for blister repair, who can drain the pool, dry the affected area, and apply specialized repair techniques. Maintain balanced water chemistry to minimize the risk going forward.
8. Leaks at Return Fittings
Return fittings are crucial for water circulation. Leaks at these fittings can disrupt water flow and lead to water loss, affecting pool operation.
Tips from Pool Builders: Regularly inspect return fittings for leaks and tighten any loose fittings. Replace worn or damaged parts promptly. For persistent leaks, seek professional assistance to replace fittings and seal leaks effectively.
9. Concrete Decking Separating from the Pool
Concrete decking around a fiberglass pool can separate due to ground movement, improper installation, or freeze-thaw cycles, which affects both appearance and safety.
Tips from Pool Builders: Ensure decking is installed by experienced professionals with proper compaction and support. Regularly inspect for signs of separation or movement — early detection prevents larger issues. If separation occurs, hire professional pool builders to reattach the decking and address underlying causes.
10. Coloured Surface Repairs
Fiberglass pools often feature coloured surfaces that enhance their aesthetic appeal, but repairing these surfaces can be challenging since colour matching is crucial to maintaining appearance.
Tips from Pool Builders: Use repair kits specifically designed for coloured fiberglass pools, which include colour-matched materials that blend seamlessly. Maintain the coloured surface by keeping water chemistry balanced and avoiding abrasive cleaners. For extensive repairs, consult professional pool builders for seamless results.
11. Spider Cracks in Gelcoat
Spider cracks are small, web-like cracks that appear on the gelcoat surface, typically caused by stress, impact, or natural wear over time.
Tips from Pool Builders: Inspect the gel coat regularly for spider cracks — early detection allows for timely repairs. Avoid placing heavy objects on the pool edges and ensure the pool is installed on a stable foundation to reduce stress on the gelcoat. Hire professionals for specialized gel coat repair techniques.
12. Bulging Pool Walls
Bulging pool walls can result from ground pressure, improper installation, or hydrostatic pressure, potentially compromising structural integrity.
Tips from Pool Builders: Ensure the site is properly prepared before installation, with properly compacted soil and a stable base. Regularly inspect the pool walls for signs of bulging — early detection prevents more severe structural issues. If you notice bulging, seek professional help to assess and reinforce the walls.
Advanced Maintenance Techniques
Maintaining a fiberglass pool requires more than just routine cleaning and chemical balancing. Advanced maintenance techniques can extend the lifespan of your pool and enhance its appearance. Here are some tips from expert pool builders in Toronto.
Acid Washing
Acid washing is an effective method for removing stubborn stains and buildup on your pool’s surface. This process involves using a diluted acid solution to clean the pool, making it look like new again. It’s a specialized technique that should be performed by professionals to ensure safety and avoid damaging the pool’s surface.
Resurfacing
Over time, the gel coat on fiberglass pools may fade or wear out. Resurfacing involves applying a new layer of gelcoat, restoring the pool’s original lustre and colour. This process not only enhances the pool’s appearance but also protects it from further damage. Professional pool builders can perform this task with precision, ensuring a smooth and durable finish.
Equipment Upgrades
Upgrading pool equipment can improve efficiency and reduce maintenance efforts. Consider installing energy-efficient pumps, advanced filtration systems, and automated chemical feeders. These upgrades enhance the pool’s performance and also contribute to cost savings and ease of maintenance. Consulting with fiberglass pool installers can help you choose the best equipment for your pool’s needs.
Frequently Asked Questions
What is the best way to properly level the ground for a fiberglass pool installation?
The best way to properly level the ground is to first remove any vegetation or debris from the area, then use a laser level or transit to ensure the ground is perfectly level. Next, compact the soil using a plate compactor to create a stable base, and add a layer of sand or gravel to further level the ground and cushion the pool shell.
How long does a fiberglass pool installation typically take?
A fiberglass pool installation usually takes between 1 to 3 weeks, including site preparation, excavation, pool placement, backfilling, and finishing touches. Weather conditions and site-specific factors can affect the overall duration.
How often should I inspect my fiberglass pool for potential problems?
It’s recommended to inspect your fiberglass pool regularly, at least once a month, to identify any issues early and prevent them from worsening.
Can I repair minor cracks in my fiberglass pool myself?
Yes, minor cracks can be repaired using specialized repair kits designed for fiberglass pools. However, for significant cracks or structural issues, it’s best to hire professionals for proper repair.
Are there specific permits required for installing a fiberglass pool?
Yes, installing a fiberglass pool typically requires obtaining permits from your local municipality. Permit requirements vary based on location and pool size — check with your local authorities or your fiberglass pool builder to ensure all necessary permits are obtained before starting installation.
How often should I perform acid washing on my fiberglass pool?
Acid washing is a specialized maintenance technique that should be performed occasionally, typically every 3 to 5 years, or as needed to remove stubborn stains and buildup.
Leading Pool Builders in Toronto For Over 25+ Years
Land-Con Luxury Pools has been a trusted name in pool design and building for over 25 years in Toronto. Let our expertise and dedication bring your dream pool to life. From innovative designs to meticulous craftsmanship, we’re committed to exceeding your expectations. Whether you’re planning a new build or need help resolving one of the problems above, our team handles every detail from site preparation to final touches.
Trust our experience, passion, and unwavering commitment to quality as we transform your backyard into a haven of tranquillity and enjoyment. Whether you are looking for a concrete pool, vinyl liner pool, or fiberglass pool installation, we have the expertise to deliver the best. Contact us at 416.504.5263 or email us at info@landcon.ca to schedule a consultation and experience the difference of working with one of Toronto’s leading pool builders.
Our service regions include Toronto, Markham, Etobicoke, Vaughan, Mississauga, Richmond Hill, Barrie, Brampton, Hamilton, Ottawa, Woodbridge, North York, and the surrounding GTA.
