Do Fiberglass Pools Float Out The Ground?

First, a little fun fact from the Solid Structures team here in Virginia Beach. Fiberglass swimming pools float. In fact, we’ve floated one to a client’s house because there was absolutely no easier way to get the fiberglass pool shell into the waterfront backyard. When all other pool builders said “no” we said “yes.” If you are interested to see this effort in action, it can be viewed here on our YouTube Channel. While there, be sure to check out some of our client testimonials in regards to fiberglass pool installations.

Okay…So, will rising ground water make a fiberglass pool just float or pop out of the ground? Here’s the short answers…

• Yes: If not installed properly and if the homeowner drains the pool
• No: If installed properly and the pool is drained after evacuating all ground water

All Pool Types Float

With that said, all types of inground swimming pools can float, to include concrete pools and vinyl liner pools. Pool installers or pool builders who don’t have the means to install fiberglass pools may use this “fiberglass pools float” disinformation as a scare tactic to convince homeowners to buy a different pool type. If you are interested in fiberglass swimming pool design consultation and full installation, we’d be more than happy to go over the difference between pool types, longevity, and cost over time.

Overall, homeowners should not be concerned about fiberglass inground pools floating up. Let’s go over some supporting information for those answers.

1. Pools Can’t Float When Completely Filled with Water

When a fiberglass pool is filled with water, floating it out of the ground would break the rules of physics. There is no buoyancy of the fiberglass pool shell when filled to the correct water level. Fiberglass swimming pools should only be drained if there’s a required repair to be done by a certified pool professional. In other words, don’t drain significant amounts of water out of your pool to correct a water chemistry issue. The water level should always be around the middle of your skimmer opening.

Other pool types, such as concrete and vinyl liner pools must be drained for regular maintenance (resurface or vinyl liner replacement).

2. Proper Installation – Ground Water Standpipe

Fiberglass pools must be installed with a ground water standpipe. This pipe, typically at least 8 inches inside diameter and perforated, runs from the top of your pool deck all the way to the deepest part of the excavated hole for the fiberglass pool shell. When surrounded with the proper backfill (e.g., #57/¾”clean washed stone) it enables you to visually see the ground water level. If the pool must be drained for a repair, a pool professional would insert a sump pump to the bottom of the pipe and drain out all accumulated ground water prior to draining the fiberglass pool.

This pipe also serves as a hydrostatic pressure release to decrease the buoyant force of rising ground water from pushing up on the bottom of the pool.

3.  Proper Backfill Material – Clean Angular Shaped Stone

Clean/washed stone with angular shapes, ranging from ½” to 1” (typically referred to as #57 stone) has locking properties (does not shift position once in place) and allows for proper drainage to the ground water standpipe mentioned above. If the contractor chooses to use sand as a backfill material, it may shift position over time as ground water rises and falls. Additionally, the ground water standpipe will collect with sand. If the pipe is wrapped with a filter sock, that sock can clog. Using #57 stone allows pool owners to visually see ground water through the pipe and evacuate it, if needed.

Feel free to contact us at Solid Structures for a complete fiberglass pool design and installation consultation. Take a look at our fiberglass pool gallery showing a variety of pool shapes, sizes, and colors…all of which have never just floated out of the ground here in the Virginia Beach, Chesapeake, Norfolk areas of Hampton Roads / Coastal Virginia.