Fiberglass Pools: Why They Pop Out of the Ground

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Fiberglass pools have been a popular choice among pool owners for decades. But there is one question that most people ask themselves when considering this type of pool: Why do fiberglass pools pop out of the ground? The answer to this question is multi-faceted and has more than one reason behind it.

Fiberglass pools are installed into holes that were dug by excavators or machines, which requires a lot of force and pressure to be applied on the bottom side. With all that pressure, it’s not uncommon for these types of pools to pop out as soon as they’re put in place!

I have seen this question online multiple times so I dug in to understand it much better to explain why it could be a concern or could be highly overblown. Sometimes the need for renovations can have other implications and be required to salvage the lifespan of your inground swimming pool.

Can a Fiberglass Pool Pop Up?

The fact is that a pool, regardless of material or pool type, may easily fall out of its hole if underground water or heavy rains occur.

The reason a fiberglass swimming pool will float has to do with the accumulation of trapped water behind the pool and under the pool floor, which cannot escape because there is no space for it to go.

The hole, as a result of the water pressure build-up, turns into an underground pond. The upward pressure from the rise in water pressure transforms the pool into a boat, and it will perform the primary function of a boat, which is to float. The scientific term for this state is hydrostatic pressure.

The solution to keeping any pool from floating is the installation of an in-ground pool. One technique for a pool builder to build a pool and ensure it does not float is to install a hydrostatic pressure relief valve in the hole.

A common cause of damage to a pool is the accumulation of water pressure underneath it.

Another option is to have your pool installer install a construction liner that runs beneath the pool and is connected to the pool pump. If there is any hydrostatic pressure in the pool, this line can be switched on so that it may be drained when necessary.

Fiberglass pools should also have a cantilevered concrete pool deck or rim around the pool’s edge. If you ever need to drain and maintain your fiberglass pool, the concrete edge acts as a collar to keep it in place.

A pool should always have water in it, regardless of the material used. The weight of the water keeps everything in place and prevents it from floating away. It is best to drain a pool only when absolutely required.

Reasons Why a Fiberglass Pool Would Float or Pop Up

If there is enough water beneath a watertight container, it will float. The container must not be sealed in place and should not contain water for this to happen.

When you have a pool you should always ensure it is properly filled with water. This will ensure it does not pop out of the ground or float away if there is a flood whether from storms, hurricanes, floods, or other events.

This story is mostly a myth that came about because pools that were empty and not maintained floated or popped up. This is more the exception and not the rule.

Methods To Ensure No Popping Out Happens

A fiberglass pool that is properly built, installed, and cared for will not float or pop up. So as long as the builder was installing it properly and the water level is always maintained there isn’t an issue with popping out of the ground. 

Maintain Proper Water Level

The water in your pool should always be full. This will help stop the pool from popping up and floating away.

The good news for fiberglass pools is that if you keep the water above the skimmer’s lower end, you have a decent chance of not damaging the pool.

Let your pool rest for no longer than is required to do the work that necessitates emptying it, and this problem will be far less likely to happen.

De-Watering System

If you are getting a fiberglass pool, make sure the builder includes a “de-watering system” in the installation. A de-watering mechanism is comparable to your sump pump at home.

A sump pump is used to remove extra water in the home from your basement and crawlspace so that they remain dry, while also protecting the foundation.

A de-watering system for your pool allows you to remove any groundwater that is building around your swimming pool, lowering the hydrostatic pressure and reducing the risk of damage to your swimming pool and causing it to pop out of the ground.

For example: If you live in an area where rainfall may seep underground for a long period might cause your ground under the fiberglass pool to become excessively wet, then a sump system should be employed.

A sump system will stop pop-ups. This is because it will stop water from building up beneath the pool if there is a lot of water that may gather.

Proper Backfill

After you’ve installed the de-watering system’s pit, be sure the pool is completely filled with clean ¾” stone. This makes it easier for groundwater to flow through than sand or crushed lime. Allowing the pump in the pit to remove water as rapidly as possible!

Should Your Pool Pops Out Lets Talk About How to Fix It

If the pool is not screened, the best option is to remove both the deck around the pool. Disconnect all electrical and plumbing connections, drain and lift the existing pool, dig, re-level, and re-install it to the correct grade. Finally, pour a new deck around the pool and reinstall the electrical and plumbing connections.

The most important thing to remember if your fiberglass pool pops out is that it can be fixed, but you need the right equipment. You have to hire a professional company that has all of this equipment on hand so they don’t have to rent any tools or parts before being able to fix it.

The most important thing is that your contractor must have the required license and knowledge. The licensed contractor for this work will examine and test the plumbing surrounding the fiberglass pool structure (before it is reinstalled) to look for hairline or significant cracks in the PVC pipes.

This will save you time and money by having to wait for the parts or tools that they need.

Final Thoughts on Why Fiberglass Pools Pop Out of the Ground

Fiberglass pools are not likely to pop out of the ground just because they’re empty. If you have a fiberglass pool that is properly installed, maintained, and filled with water then there isn’t an issue with it popping up or floating away.

Make sure you hire professionals to do work and if you are in a very wet area to install a sump system. If you do this then there is no way that your pool will pop out of the ground and cause damage to it or anything around it.

Hopefully, I have helped you understand this better and given you more peace of mind on why fiberglass pools do not pop out of the ground.