Taking the Plunge: What You Need to Know Before Buying an Inground Swimming Pool
I’ll never forget the look on my father’s face the day I asked for an in-ground swimming pool. I must’ve been 10 or 11 years old, and he looked at me as if I’d asked for a helipad or one less sister. “Go outside and run around the house,” he barked. Not even close to the response I had hoped for.
Back then, aboveground swimming pools were popular, but “dug-in” pools were extremely rare. In fact, there was only one in our entire neighborhood. Times sure have changed: Today, according to the Association of Pool and Spa Professionals, there are nearly 5 million existing in-ground pools in the U.S., and 175,000 to 200,000 new pools are built each year.
About two years ago I decided to take the plunge, so to speak, and began calling pool contractors to get approximate construction costs for an in-ground pool. Next, I spoke with the bank to discuss financing options. Then, a pool contractor came out for a visual inspection of the proposed pool site. As he walked around my backyard, he’d stop occasionally to kick at the dirt and shake his head. I had a feeling I wasn’t going to like what he had to say. “Well, we could put the pool here,” he said with very little enthusiasm, “but it ain’t going to be easy, it’s definitely not going to be cheap.”
Apparently there’s a vein of rock roughly the size of Mount Rushmore running behind my house. There was no way to dig the pool without first drilling and blasting out the rock. The contractor estimated the cost of blasting would run between $6,000 and $8,000, and that didn’t include the expense of removing the blasted material and excavating the hole.
I immediately called two neighbors, both of whom own pools, and discovered that they each had to blast to get their pools in. As I was bemoaning the expense of dynamite, one neighbor casually mentioned the high cost of fencing. I had completely forgotten that you’re required by law to install a protective barrier around an in-ground pool. “It cost us nearly $12,000 for the fence and two gates,” my neighbor said. And her yard isn’t much bigger than mine. “It would’ve cost only $9,000, but the contractor had to charge extra for digging the postholes, you know, because of all the rock.” My dream was in jeopardy—and severely under-funded. I suddenly felt like running around the house.
After several weeks of crunching numbers, it became apparent that I had only one course of action: I convinced my neighbor Bob to put in a swimming pool. And since I instigated this whole mess, I felt it was my duty to help Bob get the pool of his—and my—dream. Here’s what we learned along the way:
1 PICK A POOL
There are three main types of in-ground pools. In order of popularity they are: concrete, vinyl-lined, and fiberglass. In small pockets of the country, you might also find contractors building steel- or aluminum-walled pools.
Concrete pools are truly custom-built and can be formed to virtually any size or shape. These types of pools are often called Gunite or Shotcrete pools because concrete is shot from a gun onto steel-reinforced walls. (Technically, the concrete is pumped through a hose, but the term Hosecrete never caught on.) Once the concrete cures, it’s plastered to create a smooth, paintable surface.
Another, lesser-known type of concrete pool, called structural concrete, is formed and poured similar to a house foundation. This technique is often used for pools built into hillsides.
I spoke with a few concrete-pool owners who complained that they had to wear thick socks or water shoes while swimming because the pool’s surface was as rough as sandpaper. If you’re considering a concrete pool, be sure to ask the builder about the smoothness of the interior surface.
It typically takes longer to install a concrete pool than any other type—generally between three and 12 weeks—but it’s considered the strongest, most durable type of pool. In fact, there are many concrete pools still in use today that are well over 50 years old. And, unlike any other type of in-ground pool, existing concrete pools can be remodeled, enlarged and updated.
Vinyl pools are made from a preformed flexible liner that fits into the hole and attaches to a reinforced wall frame made of steel, aluminum or non-corrosive polymer. Most vinyl pools are rectangular, but L-shaped and freeform liners are also available. And vinyl liners come in dozens of patterns and colors to satisfy anyone’s personal preference or poolscape design.
When considering a vinyl pool, be aware that pool toys, pets, and sharp objects can puncture the liner. And while liners can be repaired, play it safe by choosing one that’s at least 20 mil thick. Construction time for a vinyl-lined pool is generally one to three weeks.
Fiberglass glass pools are factory-molded into one giant bowl-shaped piece, which is set into the excavated hole by a crane. As a result, fiberglass pools can be installed much faster than other pool types. In some cases, installation takes as little as three days.
Fiberglass pools have a super-smooth gel coat finish that’s extremely durable and stain resistant. And, unlike concrete, fiberglass pools are nonporous, so they tend to use fewer chemicals.
However, fiberglass pools come in fewer sizes and shapes than concrete or vinyl pools. And the huge molded pools must be shipped via truck, which are often forced to take long, circuitous delivery routes. The transportation of oversized loads is regulated by individual states, so the pool-delivering trucker may have to drive around several states to deliver your fiberglass pool.
How a fiberglass pool gets to your house isn’t your responsibility, but do ask the contractor for information regarding the shipping method, additional shipping fees and the approximate delivery date. And remember, there must be adequate space in your yard for the crane to drive to the pool site.
All three types of pools—concrete, vinyl and fiberglass—are available nationwide. However, certain types are more prevalent than others in certain regions. For example, fiberglass pools are popular in the south, while concrete pools dominate the northeast. Vinyl pools are sold in most areas. Aren’t sure which type of pool is best for you? Rely on the expertise of local pool contractors. If they’re all installing the same type of pool, there’s probably a very good reason why. (It often has to do with the local climate and soil conditions.)
It’s difficult to say how much you’ll pay for an in-ground pool. Cost varies widely depending on the region of the country, type of pool, soil condition, circulation system, accessories and, of course, the size and shape of the pool. Even the time of year can influence the price; some contractors offer discounts for pools built during the off-season when business is slow.
Generally speaking, concrete pools are the most expensive, followed closely by vinyl-lined pools, and then fiberglass. However, a high-end, tricked-out fiberglass pool could cost more than a barebones concrete pool. I can tell you that here in New England, my neighbor—and new best friend—Bob paid nearly $40,000 for a 20x40-ft. concrete pool. That price included the filtration system, water fill up, underwater lights and stone coping around the pool’s edge. But it didn’t cover the cost of the fencing, landscaping, lounge chairs, outdoor lighting and other pool-related items. When determining the total cost of a pool, take into account these not-so incidental expenses (see “Budget Stretchers” below).
As a general rule, you'll likely spend about twice the cost of the pool to complete your swimming pool project. So, if you buy a $50,000 pool, be prepared to spend an additional $40,000 to $50,000 before all is said and done.
3 ZONING REGULATIONS
In-ground swimming pools are subjected to building and zoning regulations just like any other home-improvement project. Therefore, you must apply for a building permit and receive approval before any work can begin. If your contractor applies for the permits, that’s fine, just be sure you see the authorized permits.
Building and zoning rules differ from town to town, but ordinarily you must satisfy certain setback distances from the pool to property lines, septic tanks, wells, sewer lines, wetlands, and the like. There are also codes concerning pool barriers and gate hardware. Generally, a perimeter wall or fence must be at least 4 ft. tall, and equipped with self-closing, self-latching gates. Fence boards or balusters must not be spaced more than 4 in. apart. Chain link fences must have openings no larger than 1 1/4 in. wide.
For an extra level of protection, especially if you’ve got young children or grandchildren, consider mounting alarms on all house doors leading to the pool, and installing a power safety cover over the pool. For a list of specific rules and restrictions, contact the local building department or zoning board.
4 CIRCULATION SYSTEMS
The pool’s circulation system is designed to keep the water clean and crystal clear. To do this effectively, it uses both filtration and sanitization. The heart of the filtration system is the pump, which draws water from the pool into an automatic skimmer and then through a filter. There are three types of filters commonly used: sand, cartridge, and diatomaceous earth (DE). All three types of filters work well when properly installed and maintained. An experienced contractor will help you decide which filtration system is best for your pool.
Sand filters are the oldest and most common method of pool-water filtration. They use special filter sand (pool-grade No. 20 silica) to trap dirt and debris. As the sand particles “load up” or become clogged, they trap smaller and smaller particles. Sand filters are cleaned by backwashing, which involves reversing the water flow through the filter and flushing the dirty water into a waste line.
Cartridge filters have been around for a number of years, but their popularity has only recently begun to skyrocket. This system uses large cylindrical cartridges to screen out dirt. Most pool builders recommend using large cartridges that have 500 to 600 sq. ft. of filter area. Unlike sand filters, cartridges don’t require backwashing. Instead, you simply remove them and rinse off the dirt with a garden hose, a process that uses much less water than backwashing. In fact, backwashing has become an environmental issue in the southwest and other drought-prone areas of the country. According to one recent study, if every in-ground pool owner in the greater-Phoenix, Arizona, area used cartridge filters, they'd collectively save about 1.5 billion gallons of water each year.
Diatomaceous earth is a porous powder that has microscopic openings, similar to tiny sponges. As water passes through the openings, particles are trapped. DE filters can strain out dirt, dust, algae, and some forms of bacteria. When DE filters become dirty, they’re cleaned by backwashing or by draining the clogged filter into the waste line. Then, fresh DE is added to the filter.
A filtration system removes debris, but a chemical sanitizer is required to kill organic contaminants, such as bacteria and algae. And an oxidizer is used to kill both inorganic and organic contaminants. There are three EPA-registered sanitizers commonly used in swimming pools: chlorine, bromine, and PHMB. Chlorine is by far the most commonly used pool sanitizer; it’s also an effective oxidizer. When dissolved in water, chlorine releases free-available chlorine, also known as hypochlorous acid. There are different kinds of chlorine sanitizers available, including cal hypo, dichlor, gaseous chlorine, liquid chlorine, lithium hypochlorite and trichlor.
Bromine (hypobromous acid) tablets can also be used as a pool sanitizer. The solid white tablets slowly dissolve to produce free-available bromine, which is also a strong oxidizer.
PHMB (polyhexamethylene biguanide) is a pool sanitizer that’s used in conjunction with hydrogen peroxide and an algicide. Hydrogen peroxide is used as an oxidizer.
Salt chlorine generators represent the very latest advancement in pool sanitization. Instead of using standard pool chlorine, this system transforms common table salt into chlorine. And contrary to what you may have heard, salt chlorine generators don’t create saltwater swimming pools.
The actual chemistry behind this system is too complicated to fully explain—and besides, I don’t really understand it—but here are the basics:
Salt is automatically dispensed into the pool (about one teaspoon per gallon of water), and as it dissolves, salt flows through a generator cell, which electrolytically converts it to pure chlorine. The converted chlorine is then pumped into the pool to sanitize the water.
A salt chlorine generator initially costs more than other types of sanitizers, but you’ll save money by not having to buy chlorine. In fact, most pool owners recoup the additional cost of the salt generator in about five years. Another big advantage is that salt generators produce “soft” water that doesn’t burn eyes or dry out skin.
Note that it’s important to test the pool water before arbitrarily adding chemicals. Take a water sample to a local pool store for analysis, or buy a do-it-yourself test kit. Keep the pH between 7.2 and 7.8, and maintain the alkalinity between 80 and 120 parts per million. And during the very hottest stretches, check the water chemistry several times a week. Keeping the pool water properly balanced is the very best way to control sanitizer consumption.
As mentioned earlier, the true price of an in-ground pool is often about twice the cost of the pool itself. That’s because there’s so much more to an in-ground pool than a hole filled with water. To truly create an inviting backyard oasis, you need to enhance the landscape, buy accessories and invest in pool maintenance.
Here’s a list of items that aren’t typically included in the price of the pool: outdoor lighting, landscaping, pathways, decks, fencing, patios, privacy screens, whirlpool spas, outdoor sound system, water test kits, shade structure, patio furniture, equipment shed, storage cabinet, pool toys, and additional outdoor electrical outlets. Now you’re not likely to need all of these items, but keep them in mind when formulating your construction budget. And be sure to invite me over once the pool is open.