poolnerd

There are two basic kinds of pools: above-ground and inground. Each has its advantages and disadvantages, but they all have a few things in common:

• A pool is just a vessel that holds water for folks to swim and frolic in. It doesn’t much matter if that vessel is made of concrete, fiberglass or vinyl. From a frolicking standpoint, its all the same.
• The water in that vessel must be kept clean and sanitary, so those same frolicking folks don’t get nasty ailments from water-borne creatures like bacteria and viruses. That’s where filtration and sanitation come in to the picture.
• While the pool is busy holding water, it must — above all — be safe. Pool safety is a whole series of articles in itself. But besides the obvious issues like supervision, fencing, knowing how to swim and perform CPR, there other issues not talked about much that need to be covered: electricity in and around the water, hair or bathing suits being sucked in at drains, appropriate types of (non-slip) decking, and so on.

But let’s get back to sorting out pool basics.

Above-Ground Pools

Most above-ground pools are of the steel-wall-with-vinyl-liner type (think “Doughboy”). There are also soft-sided ones (like “Splash Pools”), and inflatable ones. Most of them come with a pump and filter mounted on a base, connected to the pool with hoses. One hose brings water to the pump from the skimmer (and sometimes another hose or pipe from a drain in the bottom of the pool, also connecting to the pump’s suction or inlet port). Another hose carries filtered water back to the pool.

The chief advantages of above-ground pools are their low price, and their portability. A Doughboy-type pool may cost one-fifth to one-tenth what a similar sized inground gunite pool costs. And, if you need to leave town, you can disassemble your swimmin’ hole and take it with you. You’ll probably need to get a new liner when you get to wherever you’re going, though.

One of the chief drawbacks of above-ground pools are their looks. No matter how they try to make ‘em look good, you still have a long, steel wall, four feet high in your backyard. Another drawback is their comparatively short lifespan. I’d say the typical above-ground pool lasts ten to fifteen years. But, for a lot of families, that’s more than enough.

If you want to go swimming, but don’t have much scratch, an above-ground pool is the best bet.

Inground Pools

Inground pools can be built of:

• Poured concrete, applied over a cage of reinforcing steel (”rebar”). This kind of pool isn’t very common these days. I’ve seen this type of construction in old municipal pools, and even a few big residential pools from long ago. Like the from 1930s or ’40s.
• Gunite or shotcrete, applied over rebar. Both are special types of sprayed-on concrete. The difference is in whether the mix is pumped through the hose to the pool in a wet, or dry, form. Once finished, they both have similar looks and properties.
• Vinyl liner, stretched over a steel or wooden wall. The liners can be made to fit nearly any shape and size of pool, and come in an amazing variety of colors and patterns. Realistic looking tile patterns can even be printed on the liner to like conventional inground pools.
• Fiberglass, usually with a thin gelcoat veneer for a smooth finish. These pool shells are made at a factory and trucked to the site. A hole is dug, the pool set in the with a crane, then sand is backfilled between the pool and excavation. Sizes, shapes and configurations of ‘glass pools are fairly limited and vary by manufacturer.

Different types of pools are more prevalent in different areas of the country. Out here in the west (I’m in sunny Southern California), gunite/shotcrete pools are the most common. In the Midwest, vinyl liner pools are popular. Back east, it seems that there’s a mix. And fiberglass pools are scattered all across the land.

Gunite Pools

Gunite/shotcrete pools can be made to any shape and size. I mean any. There’s a pool around here that was made to look like the Batman logo. You know, like that searchlight thing you see shining in the night sky when Batman is needed (or something like that — my superhero knowledge is a bit sketchy). Incidentally, the shape has little influence on the price. Perimeter and surface area are main the concern. A rectangle and a profile of Elvis’s head cost pretty much the same, if the size is pretty much the same.

A gunite/shotcrete pool shell’s structure must be designed by an engineer. The pool builder selects the appropriate sections and schedules of the engineering plan. For instance if there are conditions like expansive soil, or a hillside or building close to the pool, this must be considered. Also, this type of pool allows cool features you don’t see in other types: beach entries, swim-up bars, vanishing edges, pebble finishes. All of this customization — site considerations, special designs, unique features — can sometimes be reflected in the cost. But it also means that you can the pool best suited to your yard, and to your family’s lifestyle.

Vinyl Liner Pools

Vinyl liner pools come in a wide variety of shapes, sizes and colors. Some even have “tile” printed on them, perhaps so they will look more like gunite pools. The excavation is similar to other types of pools, but some types are significantly over-dug to accommodate steel panels that comprise the pool wall. The void between the excavation and the wall can be backfilled later in the construction process. They are popular in some parts of the country, like the Midwest. Since they are rare in this part of the country, I can’t give you much authoritative info on pros, cons and costs.

Fiberglass Pools

Fiberglass pools are more limited in choice of shape and size than their gunite/shotcrete cousins. But the installation is much, much faster. Dig a hole, drop in the pool with a crane, backfill with sand while filling the pool with water. Boom! You can go a-frolickin’ just a few days after the work commences. Those other pools can take months, sometimes half a year or even more, to build. And the fiberglass salesmen tell you that fiberglass is like 30 times as strong as concrete. I dunno about that, though. Is that strength measured in compression, or in tension? All I know is that around here, we use concrete for house foundations. Not a single fiberglass house pad in the whole county. Now, I’m no engineer, but there’s probably some reason for that.

They All Just Hold Water for You to Swim In

Well, there you have it. Different types of pools, unique advantages and disadvantages. But, in the end, they all just hold water: hop in, close your eyes, and they all swim pretty much the same.

This entry was posted on Saturday, July 22nd, 2006 at 7:36 pm and is filed under For Homeowners, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.