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The Top 8 Problems with Fiberglass Pools

Updated: Dec 31, 2020

Floated Fiberglass Pool

In 2020 Fiberglass Pools are taking the pool industry by storm. However, things have not always been sunshine and rainbows for fiberglass swimming pools. It's time to be honest and address the elephant in the room. Fiberglass pools have had their shortcomings in the past and in this article, we will address those problems and what we have done to solve those issues.

Problem #1: Fiberglass Pools Float:

This is more nuanced than a simple yes or no answer but, yes a fiberglass pool can float. However, the same can be said about any type of pool. Even concrete pools!

Sump Pump and exposed sump pipe on a fiberglass pool
Fiberglass Pool Sump Pipe Lid

Cause: The cause of a floating pool is excessive hydrostatic pressure under and around the pool. Hydrostatic pressure is just a fancy phrase for groundwater pressure under and around an in-ground pool. Too much groundwater pressure and not enough water in the pool will cause a pool to float out of the ground or move. That is why it is recommended to not drain any type of pool without first seeking the assistance of a pool professional.

Solution: Pool Pros Tundra Loc Installation System. Our Tundra Loc installation system requires a 3/4" clean stone base and backfill for our fiberglass pools. This type of stone allows water to freely flow in and around your pool while reducing hydrostatic pressure. Secondly, we install an 8" Schedule 40 PVC standpipe in the deep end of the pool dig and finish it off on the pool deck with a skimmer lid. At any time this lid can be removed and a sump pump can be installed in the pipe to pump out groundwater.

Problem #2: Osmotic Blistering

Osmotic Blistering is an unsightly blister on the surface of a fiberglass pool or boat.

Fiberglass Pool with Osmotic Blisters
40 year old Fiberglass Pool with Osmotic Blisters

Cause: The use of polyester resin behind the gel coat. When polyester resin comes into contact with water it deteriorates creating a blister and over time it pushed the blister out to the surface much like the photo to the right.

River Pools
River Pools Manufacturing Schedule

SOLUTION: The installation of a layer of 100% pure Vinyl Ester Resin behind the gel coat. Vinyl Ester Resin is waterproof and resistant to Osmotic Blistering.

Cross-Lynx is a series of cutting-edge materials and manufacturing best practices that ensure you have the strongest, most durable fiberglass pool possible. Without getting too technical, the core premise of Cross-Lynx is to drive a process called polymerization during the manufacturing process. Polymerization is the process by which polymer molecules cross-link together to form a web of strength within each layer of the shell structure. Each layer of each fiberglass pool undergoes this polymerization process. The more cross-linking that occurs, the stronger and more corrosion-resistant the pool shell becomes. Cross-Lynx Composite Technology was created to fuse the entire structure together, layer by layer, into a single composite structure that's incredibly strong and durable.

Problem #3: Leaks at return fittings:

Cause: Improper backfill material, or the use of the wrong return fitting.

SOLUTION: Our Tundra Loc installation process requires us to use only 3/4" clean stone. This stone is 97% compacted on placement so once placed it won't move or settle, which may cause stress on plumbing. Sand or other backfill material can settle if putting pressure on wall fittings and plumbing causing them to leak or crack. Our backfill material and the use of the CMP Fiberglass Pool Return which has a large 2" nut on the back properly secures the return to the pool. We also do not use gaskets provided with return or wall fittings. Those gaskets squirt out of place when tightening fittings to the wall. To replace those we use only 100% pure silicone as a sealant for all wall fittings. We also insert a 1.5" piece of PVC inside the return fitting which fuses the front piece of the fitting to the back piece of the fitting creating one solid fused piece to reduce the likelihood of leaks even further.

Problem #4: Fiberglass Pools look like bathtubs

Cause: Early on fiberglass pool manufacturers did not necessarily have the imagination or foresight to create bold and intriguing designs. Most were white and either kidney or semi-rectangular with no tile. So in all fairness fiberglass pools did use to look like big bathtubs.

"Old School Fiberglass Pool"
Bathtub Style Fiberglass Pool

Solution: Not so much anymore! With today's modern manufacturing processes and the countless accessories available for fiberglass pools they hardly look like bathtubs anymore.

Not so bathub style fiberglass pool
Not so bathub style fiberglass pool

Problem #5: Fiberglass Pools Crack

Cause: Improper backfill or base (settling), Unlevel pool base, improper handling of the pool

Solution: Our Tundra Loc Installation System that requires a 4" thick 3/4" clean stone base and backfill. This prevents settling of the base and backfill material reducing the chance of shifting and settling. Proper handling with a crane and proper rigging and bracing when lifting and moving the pool. Pools should be lifted with 4 straps and the use of a steel spreader beam to evenly displace the weight of the pool to prevent it from collapsing in on itself when lifting and setting.

Offloading a Fiberglass Pool
Properly Offloading a River Pools D24 Fiberglass Pool

Problem #6: Plumbing Leaks

Cause: Flex Pipe. In the early 2000's most major fiberglass pool manufacturers were recommending the use of flexible PVC pipe for fiberglass pool plumbing. This was fine until builders began to realize that termites loved to eat flex pipe, stone backfill could puncture flex pipe and it could collapse on suction lines.

Solution: Plumb using rigid schedule 40 PVC pipe and heat bend as needed. Rigid PVC is resistant to termites and won't collapse on suction side plumbing runs.

The River Pools Way
The River Pools Way Advanced Fiberglass Pool Installation System

Problem #7: You can't customize fiberglass Pools

Cause: There actually is no cause. You can customize fiberglass pools.

Solution: The inventions of tanning ledges, spillover spas, waterfalls, raised pools, above ground fiberglass pools, beach entry pools, negative edge pools and more. The options are limitless. Check out this amazing pool from our friends at Signature Pools in Illinois. Just amazing.

Custom Fiberglass Pool
Custom Fiberglass Pool by Signature Pools of Chicago

Problem #8: Concrete decking separating from the pool

Cause: Improper backfill and no concrete collar at the pool to lock the concrete to the pool.

Solution: Our Tundra Loc installation system uses composite rods and a 12" thick collar of concrete to fuse the pool coping into the concrete thus not allowing for the two to separate.

As you can see the problems that did exist at one time have been overcome by advances in manufacturing best practices and revolutionary installation systems that eliminate the problems of yesteryear. For your free site consultation contact Pool Pros, Wisconsin's fiberglass pool experts, today at 920-771-0107.



Green Bay, WI 

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  • This website contains an abundance of information that has been created over the last decade or more. Some of the content on this site may reflect prices, perspectives, processes, entities, and names that were relevant at the time but may not be as relevant today. Consumers should consult a Pool Pros associate for the most accurate and updated information based on the unique conditions of their property. Consumers should verify specifications with the installing Pool Pros rather than relying on the information on this website, which is not intended to be a final specification.

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