How Much Does It Cost to Build an In-ground Fiberglass Swimming Pool?

Pools make a fun addition to many properties, giving you the opportunity to cool off on a hot day right in your backyard. Fiberglass ¹ pools are one of the more common types of inground pool, requiring less ongoing maintenance and electricity than other materials. Inground pools made of fiberglass can enhance the resale value of your home, making it more attractive to potential buyers.

The average size of an inground fiberglass pool is around 12-feet by 24-feet and costs around $60,000 on average, including all labor and decking.

Pros and Cons

Like many materials, a fiberglass pool has its positive and negative attributes. Since it isn’t the only material you can build a pool from, it helps to weigh the pros and cons before building.

Cost Factors

There are several factors that determine the ultimate cost of the pool. Size is the one of the biggest determining factors. While fiberglass pools are limited in how big they can get, they can vary in length and width as well as depth, which can impact your final costs.

The pool shell and the excavation of your yard will both be determined by the size, which in turn means that the costs of both of these areas may fluctuate as well. This is also true of the amount of water you will need to fill the pool. If you live in an area where water must be purchased and delivered that will be another contributing factor for the final cost.

The shell of the fiberglass pool will be delivered in one piece. There is usually a delivery charge associated with this service, which can be impacted by how far the delivery area is from the supplier.

Finally, the accessories and features that you add to the pool, such as filters, heaters, pumps ³, ladders, and other items can all have a range of costs, which will impact the final cost of the project.

Parts of the Pool

There are several parts and steps that go into the installation of a fiberglass pool. Each item has its own cost that, added together, make up the total for the project.

Designs

Unlike vinyl ⁴ and concrete pools, fiberglass pools cannot be created in endless designs or shapes. Instead, they are limited in what molds a particular company may be producing.

There are still numerous designs to choose from, however. The most common is the rectangle, which can come in many dimensions although it must be under 16-feet by 40-feet in total.

They can be found in “freeform”, kidney, and Roman styles as well. Each manufacturer will have its own mold, so one company’s “freeform” may be different than another. Because the molds are already existing, costs are usually driven primarily by the size of the pool, rather than by its shape.

Finishes

All fiberglass pools have a gel coat finish that is applied to the top surface of the pool. And this finish can take on a variety of different looks and colors, including flecked, metallic, and solid.

The way that this finish is applied, however, varies between manufacturers. Most manufacturers use what’s called a solid finish, which means that one layer of material is used to create the finish on the pool. Others, however, use a multi-coat finish. This gives you a more interesting finish, because they can apply different tones and finishes on top of one another to give you a unique color and design.

This multi-layer finish can be problematic in the long run, however. All fiberglass gel coats will eventually develop cracks. A solid surface gel coat is easy to repair and get a close match with the original color. A multi-finish surface can be more difficult to match when repairing, which means that the patch will likely show.

You will also pay more for a multi-step gel coat. A solid surface will cost around $10,000, while the same size and shape pool with a multi-coat will cost closer to $15,000 to $20,000.

Decking

Your fiberglass pool will need a deck, or a surface area around the pool that can withstand water and provide some grip when wet. Decks can be made of a wide range of materials including:

• Stone: $4,000 for material and installation without grading ⁵.
• Concrete: $4,500 for material and installation without grading.
• Stamped pavers: $4,500 for material and installation without grading.
• Aggregate surfaces: $4,500 for material and installation without grading.
• Modified wood: $7,000 for material and installation without grading.

The cost of each of these materials will vary depending on several factors including the size and shape of the deck, the color, and the exact material. For example, bluestone, slate ⁶, and limestone ⁷ can all be used around a pool deck, and each will have a different price point.

The most common pool deck ⁸ used with a fiberglass liner is concrete. Most pool installers will pour a concrete deck as part of the pool package, and will include the deck along with final grading and leveling ⁵ of the surrounding area for a total of around $10,000.

Labor

Because a fiberglass pool shell is made off site, a lot of the labor in building the pool is in the excavation, dirt hauling, and deck installation. This accounts for anywhere from $10,000 to $20,000 of the final cost of the project, depending on how much leveling is needed, how far the transport needs to be, the shape being excavated, and whether or not the deck is being installed at the same time.

The labor is carried out by the pool manufacturer that you purchase the shell from. While it is possible to hire someone directly to do the excavation, and have the pool company only install the shell, in most cases, the pool company will take care of all labor. It takes roughly 2 weeks from start to finish to have the pool installed from excavating the site, to putting in the shell, to leveling and finishing the deck.

Maintenance

Swimming pools of any material need to be properly maintained to keep them safe to use. This can be done yourself or you may hire a professional pool maintenance company to help keep your pool at its best.

The average homeowner will spend around $250 for DIY pool cleaning each month, while some homeowners will spend an additional $100 to $200 for professional maintenance.

This includes:

• Testing and balancing the chemicals.
• Testing and adjusting the temperature.
• Running the filter.
• Vacuuming the bottom of the pool.
• Brushing down the sides of the pool.
• Skimming the surface of leaves and debris.
• Adjusting water levels.
• Lubricating and fitting all the pipes, valves, and parts upon opening.
• Uncovering and covering the pool at opening and closing.

Comparing In-ground Swimming Pool Materials

Fiberglass is not the only material that you may use for your inground swimming pool. Concrete and vinyl are also options, and each will have its attributes to consider. Below, you’ll find the comparisons for cost, installation timeline, maintenance, durability, maintenance costs, and resale.

Enhancement and Improvement Costs

Water Features

Many inground pools may have water features installed to enhance the landscaping and look of the pool. These may include things like waterfalls or fountains. An average waterfall feature costs around $1,020, but you can find more elaborate versions with lights for up to $20,000.

Covers

Your swimming pool will need a cover if it is not used all year. The two most common types of cover are mesh and solid. Mesh covers run around $2,700 and are lighter and easier to install. Solid covers cost around $3,700, and can keep your pool cleaner, blocking algae growth during the winter months.

Lights

If you intend to use your pool at night, you may want to invest in pool lights as well. Pool lights may float on the surface of the pool, or you may have them installed right into the walls of the pool itself. Lights cost from $450 for incandescent lights to $1,450 for fiber optic lights.

Mosaic Inlays

Waterline mosaics can add a decorative touch to your fiberglass pool. These are small tiles made of glass or ceramic that can be installed just at and above the waterline in most cases, but you can have them cover the entirety of the pool as well. They come in many shapes and styles, and can enhance the look of the pool. Mosaics cost $75-$100 per square foot installed.

Heat Pump

If you live in a cooler climate, you may wish to add a heat pump to your pool. Fiberglass pools retain heat well, so they won’t need as much electricity to heat as other pool types. Heaters cost between $1,800 and $2,400.

Pool Vacuum

If you wish to maintain your pool yourself, rather than having someone clean it for you, it’s wise to invest in a pool vacuum. Vacuums clean the bottom of the pool, either manually or automatically, to remove sediment and debris. Pool vacuums cost between $100 and $300 on average.

Enclosure

Enclosures are a popular way to keep your pool safe and clean, and to get more use out of year round. Enclosures may be mesh or glass walled, or they may be as simple as a fence. The average enclosure costs around $22,125 to install.

Fence

Fences are integral to pools. They keep the area safe for young children and pets who may wander onto your property. Pool fences can be made of any fencing material and their cost is driven by how large the area is that you are enclosing. The average cost is around $1,120 including the gate.

Salt Chlorine System

Because chlorine ¹⁰ can be harsh on the skin, many people opt to purchase a salt chlorine system, which is more gentle. Upfront costs are around $750-$2,425, but ongoing costs are about half of what a typical chlorine pool would cost.

Retaining Wall

If your yard is sloped, a retaining wall ¹¹ can help level the area where the pool will be, while keeping the rest of the yard untouched and nicely landscaped. Retaining walls can be built in several styles, and cost around $13,700 for 50 linear feet.

Additional Considerations and Costs

• Permits. In some areas, a building permit may be necessary before beginning construction on your pool. Costs will vary by town and region. Typically, your builder can advise you as to the process and if a permit is necessary, but it is the responsibility of the homeowner to make sure that necessary permits are pulled.
• DIY. Pools are not generally considered DIY projects because of the amount of excavating involved. You need to take care not to hit utilities, to make sure that the proper backfill is used, and that the area is leveled. However, there are parts of the project that many homeowners do DIY, including the deck.
• Kits. Some swimming pool companies will offer the fiberglass pool as an all-in-one kit. This takes the guesswork out of pricing and can allow for some degree of DIY. Generally, even if you opt for the kit it’s best to have a professional evaluate your yard and do the excavating before proceeding. The total for the kit will be around $15,000 to $20,000 on average.
• Guarantee. When purchasing a swimming pool, always ask the company or manufacturer if they have any type of warranty or guarantee on the pool, lining, and/or installation. If so, get this in writing to ensure you have something to fall back on later.
• Diving Board. Fiberglass pools are too shallow to allow for safe diving. Therefore, it is not recommended that a diving board be installed with this type of pool.
• Tips. When purchasing a new swimming pool, there are several considerations you’ll need to make to ensure you’re getting the right model for you. This includes:
  • Size. Fiberglass pools are limited in size, but bigger pools aren’t always the better option. Make sure you get a pool that meets your needs.
  • Maintenance. Will you do the needed maintenance yourself, or hire it out? Both have associated costs to consider that will add to the final price.
  • Cost. Cheaper pools aren’t always the best deal, especially when you consider longevity and how often a pool may need its lining replaced.
  • Use. Who is going to use the pool, and for what purpose? A lap pool will have different specifications than a pool meant for entertaining.
• Location. Fiberglass pools can be used anywhere, but they are particularly useful in certain areas. Because they aren’t deep and use a specific backfill, they can be used in regions with high water tables. Because they hold heat well, and aren’t affected by freeze/thaw cycles, they can also withstand very cold winters.

Remodeling Terms Cheat Sheet

¹ Fiberglass: Plastic that is reinforced with glass fibers. The fibers may be mixed randomly throughout the plastic, or come in the form of a flat sheet, or be woven into a fabric

² Liner: A covering, usually made of vinyl, for the walls and floor of a swimming pool, used to keep the water in and protect the pool's surface.

³ Pumps: A device used to move air, liquid, or gas by mechanical means

⁴ Vinyl: A synthetic plastic made from ethylene and chlorine. Vinyl has many applications in the construction industry and it is widely used in sidings, window frames, roofing and gutters, among others

⁶ Slate: A fine-grained rock, typically bluish-gray in color, that can easily be split into thin layers and is commonly used as a roofing material

⁷ Limestone: A type of sedimentary rock, made up of mostly calcite and aragonite

⁸ Pool deck: Decorative border or edging around a swimming pool, often including a fence

¹¹ Retaining wall: A structure used to support vertical slopes of earth or to hold back water