Swimming Pools 101
Considering an in-ground swimming pool? Here's everything you need to know about style, type, maintenance, safety and cost.
An in-ground pool is the ultimate in backyard upgrades. If you’ve always wanted one, now may be the time. Prices have fallen during the recession by up to 30 percent. Nevertheless, it remains a big investment, so it’s important to make smart choices with regard to size, shape, site selection, and type.
Size and shape depend upon your needs, budget, available area, and design wishes. Swim spas are small pools (some only 10 to 14 feet long) that produce a manmade current against which you can swim in place. Lap pools are typically narrow but require a sizeable yard. Some are as long as an Olympic pool (25 meters) and are meant for training or exercise. Recreational pools are usually shallow at one end and deep enough for diving (9 to 11 ft.) at the other. Typically rectangular, they come in many sizes. Freeform shapes are also available and are often preferred because they blend well into the backyard landscape.
Many pool owners prefer to install their pool close to the kitchen or family room. That provides ready access to the house and makes it easier to bring food and drinks out and to clean up afterwards. It’s also easier to keep an eye on the pool from the house. That said, a somewhat secluded pool has the feel of a vacation getaway—without ever pulling out of the driveway. As long as the pool is connected to the house with a smooth, well-lit path and has a sizeable pool deck around it for outdoor furniture and a grill, no one will complain. A pool cabana, of course, allows for nearby dressing and showering.
Pool Construction Methods
The majority of today’s pools are built of vinyl, fiberglass, or concrete (called either wet shotcrete or Gunite, depending upon how it’s mixed and applied). Poured concrete pools and concrete block pools have fallen out of favor. A plaster finish is troweled over shotcrete or Gunite surfaces.
Vinyl is the least expensive option. Inside a suitable excavation, a frame of wood, plastic or metal is erected. The most stable systems are set in a concrete footing. Wall panels are then fastened to the framing, plumbing is installed, and a sand base is laid. A heavy-duty vinyl liner is fastened to the top of the frame and what remains of the hole is backfilled. Masonry coping is installed over the top of the wall.
Fiberglass pools are pre-molded in a variety of shapes and sizes. They are manufactured with steps, benches, and swimouts already in place (not the case with vinyl). After the hole has been dug, plumbing installed, and sand base laid, it is lowered into the hole and leveled. To avoid bowing, filling the pool with water and backfilling with sand must be done simultaneously. No framing is required.
Shotcrete pools are made by shooting a mix of cement, sand, water, and aggregate from a pneumatic applicator at high speeds against the earthen walls and base of the pool excavation and around a grid woven of steel rebar (reinforcing bar). Multiple passes are necessary to build the mixture to the desired thickness. The concrete must be troweled smooth before it sets, and afterwards a coat of plaster is applied.
There are two types of shotcrete, wet and dry.
- Wet shotcrete is delivered premixed with water in a truck.
- Dry shotcrete, commonly known as Gunite, is a mix of sand and cement and sometimes small aggregate. It remains dry until it reaches the nozzle of the applicator and doesn’t really mix with water until impact on the pool walls and floor.
There is some debate about which approach is stronger and longer lasting, but both processes produce durable pools. Gunite, however, demands a more highly skilled nozzle man to maintain the correct water-to-cement ratio.
Decking around a pool can be poured concrete, stone, brick, tile, or any of a variety of pavers. Wood may also be used, but it will demand more maintenance, can be slippery when wet, and is prone to causing splinters. Don’t skimp on area. The pool deck, which will be used for lounging, sunbathing, and dining, is likely to get more use than the pool!
Pool costs vary by type of pool and region. For example, in many parts of the country a fiberglass pool costs less than a concrete pool—but not everywhere.
Size is probably a more important indicator of price.
- Small pools will cost roughly between $20,000 and $30,000.
- Medium-size pools will run between $30,000 and $40,000.
- Large pools begin at $40,000 and go up from there.
- Add in the extras—diving boards, slides, decking, lighting, and automatic cleaners—and the costs can easily rise by another 10 to 20 percent.
Some pool contractors may be able to give you a more accurate estimate based upon the pool volume. For example, concrete pools in many parts of the country cost about $10 per cubic foot. As with any home improvement, request several quotes from reputable contractors along with as many references as possible.
In addition to initial cost, plan for ongoing maintenance expenses. Vinyl liners, for example, last about 5 to 10 years, at which time they need to be replaced at a cost of about $4,000. Concrete pools need to be resurfaced every 10 years or so, a job that can cost even more. Fiberglass pools have a life expectancy of 25 years, making them a low-cost option in the long term. In addition, fiberglass is less likely to stain or support the growth of algae, thereby reducing maintenance hassle and expense.
The cost of a new pool doesn’t end with its construction. Depending upon how much of it you hire out, maintenance, supplies and electrical costs can run between $1000 and $3000 a year. There’s opening and closing, cleaning, checking connections, adjusting pH, adding algaecide, surface repairs, and liner replacements. Cost-saving green alternatives are available. Before deciding upon chlorine as your primary sanitizer (it’s a major pollutant), consider some of the natural water purifiers. They include saltwater, ionization, oxidation, sonic waves, and certain types of plants. And if you’re thinking about heating your pool to extend its use into the cooler seasons, consider solar thermal heating. Of all the solar technologies, its payback is the fastest.
The Consumer Safety Protection Commission (CPSC) recommends taking measures to prevent children from accessing the water when there is no adult supervision. When planning a pool, include a fence around the perimeter in your plans. (Your municipality may demand it—and it’s a good idea in any case.) Gates should be self-closing, self-latching, and lockable. Door, gate and pool alarms should be installed along with anti-entrapment drain covers and securable pool covers. Everyone using the pool should be taught to swim, and someone in the family should be trained in CPR, first aid, and emergency response.