Sunday, 20 July 2014

Chapter 1: THE TYPES OF POOLS. How to Build Your Own Home Swimming Pool or Spa

Chapter 1: THE TYPES OF POOLS. How to Build Your Own Home Swimming Pool or Spa



In talking about the different types of pools, it's important to remember three common-sense qualities that all pools have in common.

  • All pools are gigantic holes in the ground.
  • All pools are filled with water.
  • The water in all pools needs to be filtered or purified in some way to make it safe for personal use.


There are some exceptions to these rules, in particular the first--there are temporary inflatable pools, for example, or above-ground "tank" style pools--but these tend not to have the same maintenance issues as classical swimming pools, nor are they as difficult to maintain, nor are they usually as satisfying.  We'll cover some specific issues about above-ground pools at the end of this chapter, for those who opt for that often-simpler solution.

But for the most part, there's one crucial distinction between the different types of swimming pools available to the consumer: the type of lining used.

All pools more complicated than an "ol' swimming hole" need to be lined.  To understand why, think about how much space in your home insurance policy is devoted to the topic of "water damage."  Water is an inherently destructive force.  It naturally erodes any container into which it's placed and it weakens stone moldings and the bonds between different construction elements.  Generally speaking, it shortens the lifespan of any construction project by at least half.  Your pool is no exception.

The key to pool maintenance is to think of your pool as a sustained battle between water and container.  If you think of your pool in this way, you'll naturally think of the container's attributes designed to defend against water damage and to preserve its structure over time, and you'll understand intuitively what you need to do in order to keep your pool working safely and consistently over the years.

The fundamental choice that determines how easy or how difficult it'll be to maintain your pool is the choice of lining material used to make up the "container."




Fiberglass pools are simply molded housings set into a pool excavation, otherwise known as "the giant hole in your backyard."  Sand is applied to the concrete housing in order to allow the fiberglass mold to settle and shift while remaining fairly closely packed to the actual earth.  Once you've chosen a fiberglass mold style, there's no possibility of shifting or revising it; you're stuck with what you've got.

Fiberglass is one of the most popular materials for a number of reasons.  For one, it's very easy to mold into a variety of shapes.  There are factories that do nothing but dream up different pool shapes and mold fiberglass pools to fit them.  On the "minus side", all of this factory design work carries with it a certain overhead, and fiberglass pools can be more difficult to install for this reason. 

The difficulty of designing fiberglass pools also means that although you have a great number of options for how your pool will be shapes and how it will behave, you don't have any freedom to customize within those options.  If none of the factory standard fiberglass pools appeal to you, you don't have any way to design and build a fiberglass pool that you do like (without spending a great deal of money to retain a factory and a dedicated team of pool engineers of your own, that is.)

Fiberglass also has the advantage of being flexible.  That doesn't sound like a huge advantage in pool design, but remember what we said about our basic principle: pool maintenance is about managing the war between the water and its container. 

Fundamentally, all pools are holes in the ground--and the ground can and will shift over time.  The added flexibility of fiberglass pools means that the pool body is more resistant to cracks and warping caused by changes in the earth surrounding the pool.  On the minus side, if your fiberglass pool does crack, it can be very difficult to repair the crack in a way that won't cause you additional headaches down the years.

There are other advantages to fiberglass pools, in particular safety advantages.  Fiberglass pool surfaces are smooth, making it more difficult for kids or other swimmers to get scraped or injured by brushing against rough concrete.  It's also easy to install fiberglass pools, especially when compared to the undertaking that is putting a concrete pool in your backyard--a process that can involve weeks of waiting for concrete to dry and a seriously low margin for error if anything goes awry during the construction process.





Concrete pools are the most classic swimming pool option, but bring with them a host of serious disadvantages.

Once you have your hole in the ground, the process of building a concrete pool starts with the steel framework.  Crossbars of rebar steel are inserted into the ground to provide the pool with a "cage" of support that's resistant to earth movements. 

After this, gunite or other sprayable concrete mixtures are applied to the steel framework, allowed to dry, and then recoated in order to smooth the eventual pool as much as possible.  Different finishes can then be applied to the pool, depending on price.  Tiles, paint, plaster, and pebbles are the most popular finishes, but different options are also available once the basic concrete is put in.

One major advantage of concrete pools is their customizability.  As we've said, the number of different fiberglass pools available to you is limited by the pre-fabricated options on the market.  The number of different concrete pools available to you is limited by nothing other than your budget, your imagination, and the technical competence of the contractors you choose to install your pool--in other words, you have more choice in how your pool will look and behave.

Another major advantage of concrete pools is their resistance to hot temperatures.  Fiberglass pools are good at stretching to resist changes in the earth itself, but can be damaged by extreme, prolonged heat of the type most often found in southern or equatorial regions--in other words, the kind of climate where you'd most often want a swimming pool to begin with.  Concrete pools can expand to some extent in order to resist the heat, giving your pool a longer lifetime in extreme temperatures.

However, you have a bit more to worry about when it comes to changes in the soil itself.  This is the major disadvantage of concrete pools: the difficulty of doing anything if worst comes to worst and your pool does crack or break under the strain of above-average movement in the earth.  Most of the time, concrete pools are a good, safe, flexible option.  But in some extreme situations they're not as good at holding up to natural stresses as fiberglass.

As far as other disadvantages go, there's construction time to consider.  Concrete pools take substantially longer to install and longer still to become usable--expect a minimum of about three weeks.  This ultimately leaves you with a more stable and customizable pool, but requires substantially more planning in order to take advantage of a pool before a hot summer begins, and also causes more damage to your yard and landscaping while the pool is lying there half-finished.  If you have small children or pets, you'll also have to be very careful to keep them out of the pool area while it's under construction.  This can turn into a nuisance very quickly.




Vinyl pools are one of the cheapest and simplest options for in-ground pool installation.  Vinyl pools start like any other pool: a massive hole in your backyard.  The excavation is packed with sand and the walls of the pool are created by placing pre-fabricated "panels" into the earth. 

The vinyl liner is placed in on top of this and attached to the top of the pool walls, sealing the places where the panels join (obvious weak points in the war between water and container.)  The contractor will cut holes to allow for the placement of skimmers, drains, and other plumbing/drainage features, and then the space between the vinyl lining and the pool walls is stuffed with "backfill" in order to ensure that the lining won't shift too much.

Vinyl have the distinct advantage of being very good for cold-weather climates, since they make it very easy to winterize your pool by simply draining the water.  Concrete and fiberglass pools are designed to hold water constantly, and they can suffer some major problems if allowed to drain for too long.  As we'll see in our chapter on winterizing, a lot of extra work is needed to allow these pools to remain full over the cold months without letting the water freeze and damage the plumbing.  Vinyl pools avoid these problems by simply letting you drain the whole thing easily for the winter.

But despite their basic simplicity, vinyl pools bring with them a host of maintenance issues.  The vinyl covering is very sensitive to scratches, holes, and other such damage, which requires you to place some extra safety guidelines on kids or pets who use the pool, and eliminates certain kinds of sharp metal toys from use in a vinyl pool altogether.  The vinyl covering will also need to be replaced from time to time due to age and wear. 

If you're lucky, this will happen only once or twice over a multi-decade pool lifetime; if you're unlucky you can expect to shell this out every year or two.  The need to replace the vinyl lining of a pool adds an ongoing construction expense (to the tune of a few thousand dollars) and some measure of headache to the whole situation.  A failure to do this leads to serious leaks which can damage the underlying rock/soil behind the vinyl lining.  If the leaks are serious enough it can actually cause damage to your entire house foundation.




Above-ground pools carry with them a host of problems, but have one overpowering advantage: you don't need to excavate your yard in order to install one.  Above-ground pools can usually be installed by using a pre-fab kit, assembled in a backyard, and allowed to stand for several months without significant maintenance issues.  Above-ground pools are also portable, which is in and of itself a reason to choose them if you don't own your own home or don't have a stable career which allows you to remain in one place for the foreseeable future.

Above-ground pools do require two significant pieces of maintenance.  For one, you need to have a level yard.  In many suburban areas, this won't be a problem since the land is already fairly level.  If your yard geography is a little bit more unorthodox, however, you're going to need to get your yard leveled in order to install an above-ground pool, which can be a considerable expense. 

The other significant piece of maintenance is essentially the same as any pool would require: weekly chemical treatments performed to ensure water quality, appropriate cleaning and scrubbing, and careful vigilance.

Think of above-ground pools as "training pools": they'll get you in the habit of caring for a pool on a regular basis without requiring you to make costly land modifications or without requiring you to dive into the murky waters of foundation maintenance and drainage optimization.  Just build, install, swim, and enjoy.




In general, here's a good rubric for making your decision:

  • If safety is your primary concern, OR if you live in an area known for weak soil or tectonic activity, go with fiberglass.

  • If customizability is your primary concern, OR if you live in an area known for extreme summertime heat, go with concrete.

  • If cost is your primary concern, OR if you live in an area with continually low/freezing temperatures, go with vinyl.

  • If you've never owned a pool before, you're planning to move soon, or you simply don't want to make a major financial commitment or house modification, go with above-ground--but keep your options open for the future.

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