Fiberglass Pool InstallationWhat started as an online search with fiberglass pools for sale or fiberglass pool cost has come full circle. Now you’ve chosen the perfect new fiberglass pool for your family and approved the pool builder’s plans. You’ve scoured the internet for the coolest pool toys, floats and games, and you’ve reviewed the rules of pool safety with the kids. So now you are wondering, “When will the pool be done?” Good news! A fiberglass pool installation can be quick and painless when it’s done right.



When it comes to getting a new quality fiberglass inground pool, the waiting is the hardest part. But relative to other pool types, fiberglass pool installations are fast. In fact, your new inground fiberglass pool shell can be installed, connected, filled and swim-ready in as little as three weeks! By comparison, vinyl liner pools can take up to eight weeks, and concrete (gunite) pools can take up to six months. But remember, every project is different, and actual timings can vary. NOTE: During busy install seasons, or due to unforeseen supply chain issues, project timelines may increase. Communication with your pool dealer will give you the most accurate timeline projection and ensure everyone is on the same page.

When we cite timelines for a fiberglass pool installation, we’re always speaking in terms of manufacturer-approved dealers or installers. The timeline we cite is not for a do-it-yourself fiberglass pool install or a fiberglass pool kit—they’re for fiberglass pool shells crafted by manufacturers with high quality control standards working with an established network of dealers and fiberglass pool installers. 

So, let’s take a look at the fiberglass inground pool installation process overall, along with some guidelines for approximately how long each phase might take. We’ll also take a quick look at some of the other variables, such as the accessibility of your site, your soil conditions, the weather, and local code requirements and inspections that can impact the process and your timeline.


Pre-Installation: Permit application and approval

Permit application and approval can take as little as a few weeks or as long as several months, depending on where you live. Since this part happens prior to any actual excavation, we don’t typically count it as part of how long it takes to install the pool. However, it’s important to allot time in your schedule for this process. It’s definitely not something that should wait until the last minute. Your pool builder will likely be handling the acquisition of the permits for you as part of the installation process, but they’ll need some documentation from you to get started.

Note: Almost all the following phases are weather dependent, so check your local forecast!Fiberglass Pool Installation

Phase One (2-3 days): Site excavation and setting the pool 

Your pool builder will outline the pool’s dimensions for excavation using the “dig specs” for your pool design that the fiberglass pool manufacturer has provided them.

  • The excavated area will be dug about four inches deeper and about a foot larger than the diameter of the pool than necessary to allow for backfill material to be added under and around the pool.
  • Your pool builder will add the base material that your fiberglass pool shell will rest on and carefully level it.
  • Generally, pre-plumbing will be done at this time as well.
  • Your fiberglass pool shell will be set in the hole, using an excavator or a crane.

Phase Two (2-3 days): Installing the remaining plumbing, electrical and filtration system 

  • Your pool builder will install the pool pump and filtration system lines, as well as valves, and any other wiring needed for lights and other water features.

Phase Three (2-3 days): Backfilling the shell and filling the pool 

Your pool installation team will now add backfill around the outside of the pool shell while simultaneously adding water to the pool. It’s essential that these happen in tandem so that the pressure on the shell is equalized.

  • If you have purchased a fiberglass pool with a built-in tanning ledge that does not have the Backfill Eliminator technology, you’ll need to allow an extra day or so for the backfill process, as it’s more difficult to backfill the tanning ledge than any other part of the pool.
  • If you’re planning to have waterline tile, it would be installed at this point as well, which might add a day or two to your timeline.

Phase Four (Time Varies): Inspection 

  • Your pool installation must now be inspected by your local building and inspections department.
  • NOTE: Timing can vary greatly, based on your local government agencies’ schedules.

Phase Five (3-5 days): Coping, decking and auto-cover installation 

Your pool installation team will now install the coping around the edge of your pool.

  • If you’re having an automatic pool cover installed, they will complete the “pre-pour” portion of your pool cover installation.
  • Your pool area is now ready for whatever type of decking or pool patio you have chosen.
  • Once the concrete is poured and while it’s curing, your pool installation team will begin to clean up the site.
  • Once the concrete is cured, the post-pour installation of the automatic safety cover will be completed.

Phase Six (2-3 days): Clean up, water balancing and other add-ons 

  • Your pool installation team will remove their equipment and clean up the construction materials from your pool area.
  • Before you can swim, you need to make sure your pool water is safe, clean and healthy for your family. If your pool builder also offers pool maintenance service, you might ask them to help you get your water balanced for the first time. Otherwise, you may need to bring in a pool service pro to help you.
  • If you also plan to have new landscaping added to enhance your backyard swimming pool oasis, or need to have a fence installed, you’ll need to add the time that those contractors have quoted you into your timeline as well.

Are there any geographic or location-specific factors that can impact my timeline? 

What a great question! Yes, soil can play a big part in your fiberglass pool installation cost and timeline. It’s another reason why we stress the importance of finding a local dealer who knows the territory. The soil that your house sits on may make your pool installer’s job a dream or a big challenge. Does your house sit on hard bedrock? If not, thank your lucky stars. Here’s a few of the challenges you may face relative to the soil in your space: 

  • Rock. Underground rock, such as limestone, may require specialized excavation equipment and accommodations made for breaking that rock up and hauling it away. Some installers include a “rock clause” in their contracts. Basically, the homeowner will pay for the cost of hauling rock away. 
  • Clay and Sand. Clay and sand can sometimes have a high expansion capability and needs to be replaced with less absorptive fill soil during the installation process. This enables the soil to expand and contract during temperature/rain changes in a fashion that puts less stress on the pool shell. 
  • Hydrostatic pressure. When standing water creates outward and downward pressure on an object or surface that blocks its flow, it can cause bulges or movement of inground pool walls. Thursday Pools developed a patented system, the Geo-Anchoring System to prevent hydrostatic issues. A specially formulated geo-textile material is infused into the wall during manufacturing, then rolled up and secured for delivery. During installation, it’s rolled out onto the backfill, then covered, thus anchoring the pool to the earth. The walls are then better able to resist movement or bulge. 

Having covered what a fiberglass pool installation done right looks like, we hope you have a blast making amazing memories with your friends and family in your new fiberglass pool! Once your new pool is open, you’ll have countless days to enjoy the lifestyle of a fiberglass pool owner! You’re sure to throw amazing pool parties, enjoy quality family time, get fit with swimming exercise, and look forward to staycations in your own backyard for years to come.