Arista Pool and Spa, Inc.
"Born to Raise the Bar"
Inground Pools -- Wading Through the Options
It usually begins with a dream. It’s a vague sort of fantasy, the kind that comes when you gaze out
your back window onto your finely trimmed lawn, with the summer heat making waves above the ground.
A pool, you think to yourself. We need an inground pool. Then, of course, the difficult part begins:
Where would an inground swimming pool go? Which pool builder will we hire? And, perhaps before any other
questions about pool construction, what type of pool should we build? Almost all types of pools fall
under three categories: vinyl, fiberglass, or gunite pools (known more generically as concrete pools).
We’ll take a quick look at each of these three types, with the features and characteristics of each.
Before we begin, though, there are some basic similarities between all pool types. The pool
construction processes vary widely, and the pros and cons are different, but all inground pools
have one thing in common: they must follow
pool construction standards that have been set by the
Association of Pool and Spa Professionals (APSP). Furthermore, these standards are all ANSI approved,
meaning that any respectable pool builder across the nation will build according to the industry minimum
Alright, let’s take a look at the various types of inground swimming pools.
Fiberglass pools are pre-fabricated pool shells that are brought in with flatbed trailers in one
single, giant piece. A pool builder will excavate a large hole for the basin, line it with sand, and then
use a crane to lower the pool into the hole. Then, the pool will be filled with water (to prevent
buckling) and backfilled – that is, the gap around the outside will be filled in. Finally, a deck will
be built around the pool, and you’re ready to swim!
Fiberglass pools are very quickly installed, due to the relative ease of the building process. However,
this perception has made fiberglass the choice of many less than reputable
pool builders. Even though
it may seem like there’s not much to botch up when it comes to a simple “drop and fill” job, severe
bowing can occur if the process is not executed properly. Your rectangular pool could end up shaped more
like a bowtie in a few years. Be sure to choose high quality pool builders with a reputation for
Fiberglass pools are very plain, with a single color sprayed on at the factory. You do have the option
of adding tile to the walls and floor, which will lend a more distinctive look. This must be added
onsite, though, which adds to the installation cost and takes more time. Anyway, the factory surface
tends be less costly to maintain. The slick, bathtub surface has no microscopic pitting, and as a result
discourages algal growth. The result is a decreased use of algal control chemicals, and lower maintenance
costs. However, many people find the artificially smooth surface unappealing and foreign.
Additionally, the fiberglass wall and floor will not feel as sturdy as either a vinyl or gunite pool.
In both the latter types, concrete and steel lend a sense of permanence to the structure. As you walk up
fiberglass steps, however, you will feel them “give” slightly, which can feel cheap and fake. Ceramic
core fiberglass can provide more strength, but there is a great deal of debate in the industry regarding
the true merits of this material. It can be good to be flexible, though: fiberglass pools can be slightly
more tolerant of extreme freeze-and-thaw cycles. In terms of overall longevity, various manufacturers
make different claims, usually around thirty to forty years, but most customers report hairline cracks
and staining around the twenty year mark.
The nature of a fiberglass pool is that it is pre-fabricated, and this ultimately proves to be the
biggest drawback for those who want custom pools with full integration into their backyard poolscape.
Fiberglass is only available in a limited number of shapes, sizes, and designs, so if you have a unique
feature or layout in mind, you may not be able to find exactly what you’re looking for.
“Vinyl pool” might be a misnomer, since they aren’t really made of vinyl, but rather have a vinyl
liner on a concrete, composite plastic, or steel-sided pool. The thickness and quality of liners varies,
as do the decorative elements. The huge variety of liners allows for nearly every taste and preference,
with many having brilliant and diverse patterns, in addition to the standard solids and patterns.
Vinyl pools take a longer time to install than fiberglass, since the pool is actually built onsite. A
typical vinyl pool takes an estimated 4-6 weeks for full excavation and construction, although pool
builders can vary widely when it comes to pool construction times. Part of this time is to allow the
ground to settle after excavation, much like a house’s foundation. If this time is not allotted, cracking
and shifting can occur after the inground swimming pool construction is complete.
Unlike fiberglass, vinyl pools can be built in almost any shape and style, limited mostly by the
surrounding landscape and the customer’s imagination. Once the pool walls are custom built, the vinyl
liner is made to fit. Any combination of steps, sun-bathing decks, benches, spas, and walls can be
created, in addition to many other custom features.
The actual walls are made from steel, concrete, composite plastic, or some combination, but they are
lined with vinyl that is smooth to the touch. Although not as smooth as fiberglass, vinyl does tend to
be algae resistant, with minimal pitting and roughness. Vinyl liners do wear out, however: few
manufacturers guarantee more than a few years, although the actual life can be greater with better
pool maintenance. The most common cause of vinyl liner failure is tearing, which is not covered by
manufacturer warranties. A replacement liner is around $1200 - $1800, but the cost of reshaping the
bottom to accommodate your custom pool can be considerable.
Gunite Inground Pools (or concrete pools)
A gunite pool, most commonly known as simply a concrete pool, begins with the excavation of a large
hole on the poolsite. Just as with vinyl, the pool builder will set aside time for settling, and will
grade and smooth the excavation prior to continuing. Then, the pool is essentially built in layers.
First, the walls are formed with concrete forms and steel rebar. This allows for similar customization
as with the vinyl pool. Any number of fountains, spas, baby pools, steps and shapes can be created at
this point. Once the rebar is laid, the gunite application begins. Gunite, also known as shotcrete, is
concrete that has been mixed in such a way that it can be sprayed through large, powerful hoses. The
crew blasts the mix onto the rebar, where it is then shaped and sculpted with trowels. After the concrete
has cured, the surface is plastered and sealed, and any decorative finish is applied. Finally, the
construction of a concrete deck completes the job.
Gunite inground pools are very durable, and as a result, this is the pool construction method of choice for
most large public pools (e.g., Olympic size pools). It is occasionally necessary to re-plaster gunite
pools, but only about every 15 years, depending on the maintenance. And, when it needs to be done, it is
a more straightforward process than custom-fitting a vinyl liner.
When most people think of an inground pool, they think of a gunite pool. The sturdy concrete means it
won’t give when you step on it, the way fiberglass does, and there is no liner to tear, like vinyl. They
can be decorated with an almost infinite number of finishes: pebble, tiles, smooth, or even painted with
custom artwork. They allow for customizability without sacrificing the extraordinary durability of
concrete. A gunite pool is the perfect choice for those who want a custom swimming pool, tailored to
their landscape and tastes.
In conclusion, while it can be dizzying to look at all the options available, all it takes is a quick
consideration of the aspects of each type. Fiberglass, while durable and quick to install, has a cheap
feel and a lack of customizability. Vinyl pools can be customized, but the liners do not last, and are
very expensive to replace. Gunite inground pools, in contrast, offer the best of all the options: they are
infinitely customizable, with uncompromising durability and value.
So, when it comes time to make your dream a reality and build a pool, carefully weigh all of your
options. You’ll be glad you did.