Pool Bonding Mistakes

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Electricians and engineers list some common mistakes in grounding and bonding pools

Grounding and bonding can be one of the most confusing parts of pool construction.

So when pool professional and licensed electrician Alan Brotz brings on a new crew member, his first message is very clear: Know your stuff.

“I tell all my guys there is no more important wire on a pool or spa wiring system than a ground wire and a bond wire,” says the owner/president of Swim Systems Inc. in Oviedo, Fla. “The grounding and bonding around a pool are more critical than in any other application in a home, because of the conductivity of water.”

This message applies to pool contractors. Even if local codes require that a licensed electrician handle this critical stage of construction, it’s valuable to know how bonding and grounding should be done.

Here are six common mistakes made by both pool professionals and electricians while grounding and bonding pools, and some guidelines on how to avoid them.

Mistake #1: Confusing the two


Many pool professionals don’t know the difference between grounding and bonding, while others use the terms interchangeably. Even some electricians make this mistake, Brotz says.

But the two are quite different.

Grounding is a process meant to protect people against a possible fault in the electrical system. Basically, it means to electrically attach a piece of equipment to earth ground, which is at the lowest “electrical potential,” mostly referred to as 0 Volt potential. If there’s a fault, or short, the circuit breaker will trip and turn off the equipment.

To ground a piece of equipment, installers must run a properly sized wire from the equipment, through the same conduit as the current-carrying conductors and to the circuit breaker panel. Finally, the wire attaches to the ground bus bar in the circuit breaker panel.

Bonding, on the other hand, electrically ties all specified metallic elements together to minimize the differences in voltage. (In these discussions, voltage is also referred to as potential.) The pump, motor, ladder, even the water nowadays, are bonded.

“If there’s a difference in potential, that creates a foundation for current flow,” Brotz says. “If the current can flow between two pieces of equipment, then it’s just waiting for somebody to come along and be the conductor.”

Brotz gives the example of a pump and heat pump sitting next to each other, with neither bonded. “If there was a fault in the system, either in the pump or heat pump, it’s possible for either piece of equipment to become energized with a voltage other than 0 volts,” he says. “If somebody were to come up and touch the pump, then they become the conductor between the two and get shocked or electrocuted.”

To bond the system, a No. 8 wire runs from one metallic element to the next, connecting to pieces of equipment on a provided bonding lug and, thus, creating an electrical bonding grid. The wire runs through the earth, not inside a conduit.

Mistake #2: Neglecting to ground and bond thoroughly


Because of confusion between the two terms, some professionals may ground but not bond, or vice versa.

Other installers take care to do this with all the pool equipment, but then forget about less obvious things like fences or ladders.

To be clear, anything metallic within 5 feet of the water (meaning the inside wall of the pool), must be bonded. This includes the back of the light niche, ladders (both ladder pockets), diving board stands, lifeguard stands, handrails, junction boxes, pool shells and deck, if they’re made of conductive material. There are exceptions: Any small isolated parts of less than 4 inches in any dimension and extending less than 1 inch into the structure, such as rope hangers.

The pool’s rebar must also be bonded, as well as any reinforcing steel under the deck within 3 feet of the inside of the pool wall. If there is no reinforcing steel in the deck, at least one bare No. 8 (or larger) buried wire may be used, if installed in accordance with code requirements.

Generally speaking, all electrical equipment associated with the pool must be grounded.

Mistake #3: Grounding and bonding to earth


Some professionals believe that grounding can be done by driving an 8-foot ground rod into the earth and hooking the grounding wire to it. “That will not conduct fault current to trip the circuit breaker,” Brotz says. Some may believe this sends any stray current to the earth, but that’s not the purpose of grounding.

Any defective piece of equipment will remain energized. “Then when somebody comes up and touches it, it’s, ‘Good night, nurse.’” Brotz says. “That ground rod will do absolutely nothing.”

Some will even try using the earth as part of the bonding conductor. “In other words, you bond the pool together, drive a ground rod; bond the pad together, drive a ground rod. But you don’t run a wire in between,” says E.P. Hamilton III, Ph.D., P.E., an electrical engineer and president of Hamilton & Associates in Pflugerville, Texas. If you do this, the system isn’t bonded, because everything must be tied together. Otherwise, you risk current straying, if the potential between two components is different.

Mistake #4: Using the wrong connectors
When hooking up the bonding and grounding wires to a piece of equipment, you want the best connection possible to ensure that any current that needs to move has a clear path.

That’s why tying or wrapping the wire around a bolt or other metallic component on the equipment won’t do the trick. “It doesn’t insure any sort of reasonable electrical contact, particularly over time,” Hamilton says.

Instead, use clamps or lugs rated for the specific wire size and application. For instance, when connecting the wire to the pool’s rebar grid, you must use clamps that are UL approved for concrete encasement. If they’re going in the ground, the tag should indicate that they are approved for direct burial. These clamps are usually made of brass and copper. The screw should be made of stainless steel or brass. You don’t want plated steel anywhere near these applications, or they will rust and eventually fail.

“As to ones that are not required within concrete, then they’re going to be standard electrical fittings like you would get at an electric supply house,” Hamilton says.

Make sure the connectors are listed for the type of wire you’re using, whether it’s stranded or solid. Electrician and pool professional David Durkin often sees stake-ons, bud connectors and terminals used with solid wire. “They will become loose after a while, because it’s supposed to mesh in, and you can’t mesh into a solid wire,” says the owner of D&M Electric in Antioch, Calif.

Conversely, you can’t wrap stranded wire around a screw. “It keeps pushing out strands, and it’s not a good connection,” Durkin says. “They should be using terminals.”

If you do want to make the connection by wrapping solid wire around a screw, wrap it clockwise, he adds. “When the screw tightens, it sucks the wire instead of pushing it out.”

When you have to pot certain connections, such as those inside a light niche, use potting kits made for that purpose. Don’t use things such as bath tub caulk, Hamilton says.

Mistake #5: Using the wrong wires
Watch where you use insulated wire. Particularly on the equipotential grid under the deck, uninsulated wire is mandated by code. Some electricians prefer this variety on the whole bonding grid to maximize contact with all relevant pieces of equipment, the water, earth and all conducting surfaces in contact with the bond wire.

There is one place where you must use an insulated wire: “If you have a non-metallic conduit going from the light niche up to the junction box, you have to pull an insulated No. 8 green wire through there,” Hamilton says. “But even that’s more of a ground wire, even though it does have some involvement in the bonding system.”

Many codes require that No. 8 wires and smaller be solid. If you’re cautious by nature, use solid wires for No. 6 as well. “If you need a wire that’s that small, you’re better off with a solid wire, just because the strands are more susceptible to environmental damage,” Hamilton says.

This is especially important with bond wires, since they’re in direct contact with the earth. “It may be buried 50 or 60 years,” Hamilton says.

Mistake #6: Believing that plastic or fiberglass elements need bonding
This mistake is generally not made by professionals, but rather by inspectors. Many of them, for instance, see the metal tension band on a plastic or fiberglass filter and insist that it be bonded.

“Don’t do anything to the tension band on that filter,” Hamilton says. “That creates a substantial safety hazard…if you do anything to the tension band. You’re affecting its mechanical integrity and ability to hold the filter together over time and under pressure.”

If that filter comes with a bonding lug, or has a metallic base with a bonding lug, then it must be bonded. But if it’s all polymer on a polymer base and it comes with no bonding lug, then it doesn’t need to be included in the grid.

Explain to the inspector that, because the band is only touching the plastic filter shell, there is no electrical connection. If the inspector won’t budge, then move the equipment so it’s more than 5 feet away from the inside wall of the pool.

You may have the same problem with plastic lights outfitted with an all-plastic niche. Show the inspector that UL has listed it to go ungrounded.

Take a slightly different path when installing double-insulated pumps, Hamilton says. Though you can’t bond them now, code requires that you run a bonding wire to it anyway. You won’t make the connection to the pump, but you must connect the bond wire to the ground wire in the junction box serving the pump. The code requires this so that if the double-insulated pump is replaced with a pump that isn’t double-insulated, then there’s a place to bond it without tearing up the pool area.

Source: Rebecca Robledo – Pool and Spa News | 5.13.2009

Plaster Pool Stains

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Years after the start-up is finished, changing water conditions can still damage and stain plaster in some surprising ways.

Gary Gripp’s story begins like so many others.

“I’d been servicing pools in this area for over 15 years when it happened,” says the service manager at Anderson Poolworks in Portland, Ore. Gripp and his team had been hired to drain, clean and refill a gunite pool, and everything seemed to have gone right. “When we left the job site, that plaster was clean as new, and the water was sparkling clear,” he says.

But the next afternoon, the customer called again, complaining that the pool’s water was grayish.

Gripp was hurrying back to the job site when he answered another call from the same customer, the water had now turned a pale shade of lavender.

“And by the next day,” he says, “the water was this beautiful deep purple — like a jewel. I wouldn’t have even guessed water could turn that color.”

The culprit, Gripp discovered, was manganese, a metal known to lend a distinctive range of tints to water: Grayish at lower concentrations, up through brighter shades of purple at higher ones. The real question was, why had manganese suddenly become such a problem for this pool?

“When we tested the fill water, we found that the manganese levels coming out of the tap were just about off the scale,” Gripp says. Luckily, he’d managed to pinpoint the problem before the manganese stained the plaster, and was able to bring the water back into balance with a sequestering agent.

Still, Gripp says he learned something crucial from the experience. “No matter how long I’ve been working on a pool,” he says, “I don’t assume anything anymore. I test the fill water on every visit, sometimes even multiple times. Your chemistry could be perfect, but until you test your makeup water you never know what it could be depositing into the system.”

As builders and service technicians around the country have confirmed, balanced water chemistry is a science — and, in its own way, an art — that reaches well beyond the start-up. Even years down the road, calcium hardness, total alkalinity, pH and other factors can shift dramatically, sometimes in a single day.

Even so, a little preparation and a lot of thoroughness can help stop these problems before they damage the plaster.

Chemical crawl

 
 

Changing water chemistry can seem to sneak up on you. Its effects, however, are often — though not always — the results of conditions that have been building up for some time.

Take metals, for example: Their level in the water can gradually rise due to a variety of factors. In dry or windy areas, evaporation removes water but leaves dissolved solids (including metals) behind, significantly raising the water’s total dissolved solids over time. If someone’s been adding a copper algaecide without testing the level regularly, the water’s copper level can rise even more quickly.

Metal deposits inside pipes can be harder to detect, and they often accumulate for years before leading to a problem. “At every pool I’ve seen that’s been around for a few years,” Gripp says, “you can cut a pipe open — even a PVC pipe — and see a deposit of some kind in there. It may be clear and slick, but something always accumulates.”

Most pool water contains some amount of dissolved metals, but these are typically harmless, and invisible to the naked eye. Nevertheless, a variety of common chemical reactions — such as the breakdown of hypochlorous acid under UV radiation and the electrolysis of saltwater in a chlorine generator — increase the water’s concentration of “free” oxygen, the form necessary for oxidation to occur.

The more free oxygen that becomes available, the more metals in the water begin to oxidize — that is, they bond with the free oxygen, which converts them into oxides. Oxidization causes the metals to precipitate out (or fall out) of solution and become visible as a tint in the water. The longer this oxidation reaction is allowed to continue, the greater the risk that the metal oxide will stain the plaster — and eventually be absorbed by its surface.

This is most common with copper, particularly in areas that experience severe storms or droughts, like the Gulf states, says Jana Auringer, owner of The Pool Lady in Coppell, Texas. Auringer travels the Southwest as a consultant, tracking down the sources of plaster stains. She says copper’s telltale pale green tint often appears in pools that experienced no staining issues prior to a bout of harsh weather, and it’s usually traceable to a chemical change in the pool’s fill water.

“[After a storm or drought], we’re finding higher levels of copper in the source water when we test it,” she says. “A lot of times, though, the metal won’t show up on water tests, because it’s already precipitated out and stained the plaster.”

Sudden shifts

 

Stains and other plaster issues don’t always sneak up so gradually, though. As Gripp discovered with his purple pool, water’s composition can seem to change dramatically in just a few days. Sometimes, water whose chemistry has remained stable for years will suddenly display a sharp drop in calcium hardness or total alkalinity. In those cases, servicepeople say, it’s probably not the same water at all.

Across the country, builders and service pros confirm that municipal water circulation has become more complex over the past few years. These days, the water that flows from a tap is a mixture of water from wells, rivers, reservoirs and storage tanks, and the proportion of water drawn from each source may vary from day to day.

Lance Sada became so frustrated by the seemingly random water chemistry he encountered on his route that he performed his own chemical survey. Using a series of brand-new test kits, the owner of A Clear Choice Pool and Spa Service in Sun City, Calif., tested the water up and down residential blocks in his area. “I found that from one street to another, the water’s calcium hardness might be as low as 20 ppm, or as high as 200,” he says. “Sometimes, the hardness from a single tap varied by 100 ppm from one day to the next.”

In cases like these, the most effective way to prevent problems is to test the pool’s fill water on every visit, before adding any chemicals. But in other situations, the source water itself is less of a problem than what it dredges up.

“Some customers get an accumulation of metal deposits in the bottom of their well,” Gripp says. “When you kick that well on, an abundance of iron, copper, manganese — whatever accumulated in that well source — will come flying into the pool during the initial burst of water.”

Pools that sit idle for the winter tend to display similar symptoms when the weather heats up. “If you shut a pool down for a period of time and you don’t empty the chlorinator, or run the chlorine off beforehand,” Gripp says, “that chlorine’s chewing away at the copper or iron inside the pipes.” When you turn such a system on, it may kick a cloud of metal oxides into the water, and create stains on the plaster.

Perhaps strangest of all, some stains only appear after a plaster surface has been freshly cleaned. “A degraded surface sometimes doesn’t attract stains because it’s so heavily scaled, or has some type of mineral coating on it,” Gripp explains. “And when you resurface it, you might find that your water chemistry looks fine, but all of a sudden you get a stain around the return.” Those stains are most likely metal oxides, to which the plaster’s exposed surface is suddenly vulnerable.

Even if you’re anticipating unpleasant surprises like these, they can’t always be avoided. If you start investigating as soon as you notice discoloration, though, it’s often possible to prevent a metal oxide from becoming a permanent plaster stain.

Getting proactive

 
 

Diagnosing the source of a discoloration takes a lot more than educated guesswork. Each pool’s chemical conditions are unique. Manganese, for instance, can appear as a gray, black, lavender or purple stain, depending on the chemistry of the surrounding water. A high TDS reading may point to an excessive level of contaminants, or it might mean you’re adding too much of a particular chemical — or any number of other issues. That’s why it’s crucial to pinpoint the problem’s origin, then confirm it with multiple tests, before you start any treatment.

To become a master of plaster problem-solving, you’ll need to focus on two related skills: Investigating all factors that affect the system, and confirming test results before starting to treat the issue.

The first skill, though it might seem overwhelming at first, is mostly a matter of knowing what questions to ask the customer, and listening carefully to the answers.

“You’ll need to get some background on when the owner first started seeing the discoloration,” Auringer says. “Was it after a heavy rain? After shocking the pool? After a new type of algae treatment? Try to find some change in circumstances to tie the problem to.”

It may also be helpful to find out if any equipment has been replaced, and ask to see the house’s plumbing to check if water has been running through old copper or iron piping. It’s also important to understand the history of the pool’s maintenance regimen, who’s been working on the pool, and what’s been added to the water over time. This can often lead to surprising (and useful) answers.

“It might sound like a lot,” Gripp says, “but if you take every pool on a case-by-case basis, you can find out everything you need to know in a 10-minute conversation.”

The second skill is also somewhat of a matter of instinct, but it too can be boiled down to some basic principles. Techs agree that you’re doing yourself a favor by testing on every visit, in more than one spot in the pool, and by testing source water regularly.

“Always start with a clean slate, and test the tap water first,” Gripp says. In fact, the first time he visits a site, he runs through every single test in his kit. “We also use the separate tests for manganese, iron, copper, phosphates and — if it’s applicable — salinity,” he adds.

Testing the water at several spots around the pool, then averaging the results, can help prevent inaccurate readings due to dead spots or other circulation problems. “Every time I’ve tested multiple spots in a pool,” Gripp explains, “there are significant pH, alkalinity and chlorine differences between them.”

Garrett and Gripp both recommend holding onto your results from the source water, and comparing them against your test results from around the pool for confirmation. “When you go to the doctor,” Garrett says, “he’s always going to check your blood pressure, pulse, temperature and so on, because that gives him a baseline reading to know if there’s anything else wrong with you. It’s no different for pool chemistry: You need to establish a baseline before you know what you need to adjust.”

Finally, before acting on your test results, it’s important to confirm them with other testing methods. At the very least, your test kit should be calibrated against a set of chemical standards, which are usually sold by the kit’s manufacturer. You can also ensure the accuracy of your results by confirming them against another type of test, such as an electronic meter or test strip.

“And that makes you so much more confident when you speak to the homeowner,” Gripp says, “because you can show them the results of multiple tests that all confirm each other.”

Source: Ben Thomas- Pool and Spa News | 2.11.2011

Perfect Water Balance

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To effectively preserve the pool’s plaster life, techs must recognize common mistakes in calculating balanced water.

Since   the 1960s, the pool industry has relied on the Langelier Saturation Index to   achieve balanced water. The traditional method has been to land right at 0.0   of an SI with an allowable variance in either direction. But the subtleties   of pool chemistry call for both a studied approach and a modified SI range.

Over   the years, experts have seen two things: mistakes in calculating SI and a   need for the Index itself to be adjusted. Here, we examine some common errors   techs make in calculating each component of the Index, as well as the   advantages of skewing SI balance toward a positive number.
Balanced water will go a long way in preserving the life of the plaster and   the clarity of the pool.

pH
Measuring pH is the least problematic portion of the SI. There are no   conversions necessary since the pH level is actually the number you’re using   to compute SI. Just be aware of anything introduced to the pool that may have   an affect on the pH.

The   most obvious pH changes will be the result of introducing sanitizers into the   pool. Acidic sanitizers like trichlor and dichlor will lower the pH. However,   you should be cognizant of CO2 loss, which can be especially dramatic in   spas.

“People   forget that when you turn the aerator on … immediately the pH goes up,” says   Joan Vienot, owner of Pool Pal Inc. in Freeport, Fla.

It’s   best to tabulate the water balance in a spa after the unit has already been   used in order to account for these changes, she adds.

Alkalinity
As most techs know, alkalinity refers to the pool’s ability to buffer the   water against pH change. When calculating the Saturation Index, however, we   are only interested in alkalinity’s ability to keep calcium carbonate in   solution.

To   calculate the correct SI factor, techs must isolate carbonate (or, in   actuality, bicarbonate) alkalinity from the pool’s total alkalinity.

Though   a host of buffers contribute to total alkalinity, carbonates and cyanurates   make up the majority of alkalinity in most pools. This is particularly true   in pools that are sanitized with dichlor or trichlor, which continually feed   cyanuric acid in the vessel.

In   order to isolate carbonate- from cyanurate alkalinity, experts generally   recommend taking a third of the cyanuric acid level from the total alkalinity   reading. For example, at a pH of 7.5, a pool with 90 ppm of CYA would have   approximately 30 ppm of cyanurate alkalinity, which you would have to   subtract from the total alkalinity reading to find the necessary SI factor.   Note that cyanurate levels at a higher pH will be more than a third of the   cyanuric acid level.

But   remember, isolating the carbonate alkalinity is not correcting any kind of   interference. The cyanurate is still buffering against pH bounce.

“There   are people applying that ‘correction’ to the alkalinity even when they’re   reporting total alkalinity,” says Que Hales, a manager for Pool Chlor   in Tucson, Ariz.

This   mistake is especially troublesome because every time cyanuric acid is added   to the pool — whether directly or through stabilized sanitizers — carbonate   alkalinity actually is being transformed into cyanurates. Even with the rapid   transformation of bicarbonates to cyanurates, the total alkalinity should   remain a relatively stable pH buffer.

TDS
—or in some cases 1,500 ppm — in the water. However, these tables were   largely put together before salt-chlorine pools became popular.

With   salt levels of 3,500 ppm, many pools with chlorine generators have from   4,000- to 5,000 of TDS in them. In these cases, even using the 12.2 number is   hardly being accurate. Your water is much more corrosive than you may think.

“If   everyone will use 12.4 for the TDS factor, then the corrosive effect of the   salinity will be accounted for,” Vienot says.

While   Vienot uses a standard value of 12.4, chemist John Wojtowicz published an   equation in 2001 to explain the changing SI values as the TDS rose over 2,000   and above. As demonstrated by the chart, a normal   salt pool will be improperly balanced if a tech uses a 12.1 or 12.2 constant.

Calcium hardness
The calcium component of saturation chemistry is often misunderstood. The   actual contributing factor to saturation issues is the amount of calcium in   the water. Calcium test kits give that value. However, some industry test   methods give total harness instead, which includes calcium but also other   components. To correctly calculate saturation values, use a calcium hardness   rather than a total hardness kit.

Although   the calcium hardness level is a direct indication of how much calcium is   available in the water to fall out of solution, it is not the primary   indicator of whether calcium actually will precipitate. pH is the primary   factor, with alkalinity in second place.

And   although lower calcium levels do limit the amount of precipitate that can be   formed, you can’t go overboard and maintain too little calcium.

“If   you don’t have calcium added to water, it’s going to leech the calcium out of   that system,” explains Greg Garrett, technical advisor for the National Plasterer’s Council in Port Charlotte, Fla.

This   is especially true of newly plastered pools that have not had adequate time   for internal cement compound transformation, he adds.

Temperature
Temperature is as straight-forward as pH, but perhaps because of its relative   simplicity, many techs don’t pay attention to the seasonal differences in   pool and spa maintenance.

Temperature   is key to the SI because as the water heats up, calcium becomes much less   soluble. This is why pools can deteriorate over the off-season and many spas   are ridden with scaling problems in the summer.

“A   perfectly balanced pool in the summer may be very corrosive in the winter,”   Vienot says. “In spas is probably where you get the most common water balance   problems. If you balance them for cold water and then heat them up 60 degrees,   you’ve got some real problems.”

Even   if all the other SI factors are within an accepted range, an unaccounted for   temperature can quickly tip the water’s balance.

Proof positive
The NPC’s new start-up guide is now recommending an ideal range of all   positive indices for maintaining pools and spas. This approach is to ensure   that the calcium in the pool plaster is not etched out into the water.

“Why   tolerate negative indices, which indicates the water is under saturated by   [at least] one parameter?” Garrett says.

Even   APSP’s recommendations call for an ideal range of 0.0 to +0.5, with an   allowable variance on the negative side.

Service   techs generally agree.

“With   most pools, we intentionally ride the Saturation Index a little bit toward the   positive side to where, if something goes wrong, we’re more likely to scale   it than we are to etch it,” Hales says.

However,   some pools — those with exposed aggregate, water features that continually   raise pH through aeration or sanitizers that require constant adjustment —   may need the full range of the “neutral zone” of -0.3 to +0.5, he adds.

Source: John Miles- Pool and Spa News | 2.13.2009

One Piece Swimming Pools

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We at Expert Pools are number one when it comes to one-piece fiberglass pools. We have a larger stock of one-piece designs than any other distributor in the world. However, it is not only quantity that separates us from the pack. The quality of our one-piece swimming pools is unrivaled because we utilize the very latest technology in their construction.

Our design team has created a unique fiberglass composite and it has developed an original coping system. Both of these advances have enhanced the strength and longevity of our pools. The majority of fiberglass pool manufacturers and distributors are still utilizing techniques that were developed in the 1970s and have long since become outdated.

What Do One-Piece Pools Offer?

A one-piece fiberglass pool from Expert Pools can be installed quickly without compromising its surface integrity or appearance. Once the pool is in place, it offers benefits that simply are not common with concrete pools or even most fiberglass models. A one-piece fiberglass design ensures that the pool will survive through many winters. It also reduces the amount of maintenance a person will have to perform on the pool. This includes large repairs and simple cleanings.

When you’re building a concrete pool, you are usually relying on sketches to envision what the pool will look like in the backyard. At Expert Pools, we will demonstrate exactly how a pool is going to be laid out. A full-sized template in the form of a piece of fabric can be shaped and placed in a yard to accurately represent the position of the pool.

We even offer three dimensional design for no additional charge.

Media Matters

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Selecting the right filter media for a particular pool can save time and maintenance headaches down the road.

 

Water   clarity is a crucial aspect of pool maintenance, whether a job site involves   a small family pool or a huge commercial vessel.

But experts agree that there’s no “magic bullet” when it comes to filter   media — each type has its ups and downs, and is ideally suited for some   situations while potentially disastrous in others.

Here, veteran service technicians and scientists share their perspectives on   selecting filter media, and walk through the process of assessing a pool’s   filtration needs.

Sand
As many service techs know, sand is the oldest type of filter media in the   pool industry — but what’s less well known is that it’s the oldest filter   media in human history, dating back to the baths of ancient Egypt.

Like many tried-and-true technologies, sand filtration works as well as ever   in a limited range of circumstances — but as today’s pool circulation systems   have grown more complex, and filtration expectations more stringent, it’s no   longer the most efficient option available.

Still, sand is widely used in commercial pool systems — particularly those   with relatively slow circulation rates. In the 1950s, when the pool industry   was still in its infancy, many public pools used rapid-rate sand filters,   which filtered water through a bed of sand with a gravel substrate. This   system was soon made obsolete by high-rate sand filtration, which uses much   smaller sand particles and no gravel. Thus, most of today’s “sand filters”   are more precisely termed “high-rate sand filters.”

These filters typically use sand particles between 0.018 in. and 0.022 in. In   size — often called “#20 standard silica sand” — though some operators   substitute other media such as zeolite, or a mixture of crushed glass and   gravel. Material at this level of fineness can usually entrap particles   between 20 and 100 microns in size.

This might sound tiny, but sand actually misses many particles that would be   caught by more modern filters.

Operators who choose sand filtration are often motivated by the desire to   keep costs down, or simply by the knowledge that the pool’s bather load isn’t   particularly high. In some cases, this is a sensible decision.
However, a sand filter can bring along other costs that might not be as   obvious. As the top bed becomes caked over with debris, its sand will   sometimes start to form vertical channels, experts explain. These channels   can reduce the area where optimal filtration is taking place because the   water is mostly flowing through the channels that have formed, instead of   diffusing evenly through the filtration media.

Another inconvenience of sand filters is that they must be backwashed   frequently — the exact timing varies according to factors such as bather load   and flow rate, but most systems require a backwash approximately once per   month. In addition, the effectiveness of a sand filter can drop drastically   if the sand isn’t replaced at least once every five years. This process can   get fairly involved — it entails scooping large amounts of sand out of the   filter, finding a place to dispose of the material, then refilling the filter   with an even layer of clean new sand.

In short, sand filters are best suited for applications where low cost is a   top consideration, bather loads are fairly limited, and yearly “refreshes”   are acceptable to both the site operator and the service tech.
 
A   traditional sand filter is composed of a large central chamber — filled with   sand and/or gravel — through which water is circulated. A diatomaceous earth   filter’s overall design is similar, but its central chamber is more cylindrical,   and is filled with grids specially designed to be coated with DE.
Diatomaceous Earth
A significant step up from sand in several ways, diatomaceous earth (DE) is   composed of the skeletons of microscopic prehistoric organisms. The complex   structure of these skeletons results in much finer filtration — down in the   range of 3 to 5 microns — than #20 sand can achieve. This fine texture,   combined with high permissible flow rates, has made DE the filter media of   choice for many of today’s service technicians.

This effectiveness comes with a price, though. First, DE is toxic to humans,   which means it’s crucial to wear facial protection to prevent anyone from   accidentally inhaling or swallowing the substance. Care must also be taken to   ensure that the powder doesn’t contaminate nearby chemicals or equipment,   where it can cause corrosion or other unwanted reactions.

Because of concerns like these, many cities and counties also have   regulations against disposing of used DE in the street, or even down public   wastewater lines.

These restrictions have led many techs to develop workarounds. Supporters of   DE recommend disposing of used media in the customer’s yard (after securing   permission, of course) where it acts as a fertilizer for plants. Another   option is to use catch basins, which allow water to drain away from the DE,   which can then be thrown into the trash.

Still, cleanup and disposal of DE can be nearly as messy as cleaning a sand   filter — or, in a way, even more so, given the media’s toxic nature. And DE   filter’s require more backwashing, experts say.

DE is ideally suited for pools with high bather loads where pristine water is   a major priority. Maintenance won’t be a cinch by any means, but proper care   will ensure effective filtration of most particles, even at high flow rates   and temperatures.

Cartridge
A major leap forward in filtration technology came with the development of   cartridge filters. Rather than using a chamber filled with loose filter   media, these filters strain water through a compact array of pleats that   catch particles down in the range of 5 to 10 microns in size — about a third   the width of a human hair.

Though they don’t catch particles quite as tiny as those caught by DE   filters, cartridge filters are more efficient, especially in pools with   relatively low bather loads and flow rates. In these conditions, a cartridge   filter with a footprint of a few square feet can filter a volume of water in   the range of 500 square feet; far more than a sand filter of the same size.

Techs also report that these filters tend to be resistant to breakdowns and   serious clogs, and are much easier to clean than sand filters.

And unlike sand and DE, cartridges don’t require backwashing or regular media   replacement. Instead, all a tech needs to do is remove the cartridge from the   filter tank and hose it off; or, in some cases, dip it in a mild muriatic   acid solution to remove particularly stubborn particles.

The downside is that if this cleaning isn’t performed regularly, cartridge   filters have a tendency to clog, especially in pools with high bather loads,   techs report.

Thus, cartridge filters are best suited for applications with low to moderate   bather loads and water volume, such as residential pools that see usage a few   times a week. If simplicity of maintenance is a high priority, a cartridge   system may be ideal.

Source: Ben Thomas- Pool and Spa News | 1.27.2012

 

Liquid chemical feeders

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Liquid chemical feeders can simplify pool maintenance — but an awareness of their workings is crucial for effective use.

For much of the pool industry’s history, chemicals have been added to the water in two basic ways: By pouring solutions into the pool, or by placing tablets in a feeder of some sort. These techniques are both simple and time-tested, but they’re not always ideal — especially for pools with high bather loads, or those that require rapid chemical adjustments.

This has led some manufacturers to develop new types of mechanical feeders which add precise doses of liquid chemicals to the water as needed. Though many of these feeders work in conjunction with automation systems on large commercial sites, they’re also growing in popularity for residential applications.

Here, we talk with experts on liquid chemical feeders to get a sense of how the main types work, where they’re most useful and how they should be maintained. A working knowledge of these devices will enable more effective service practices and promote clearer dialogue with those clients who use chemical automation.

 

Mechanics
An understanding of liquid feeder applications begins with a grasp of their workings.

Many of today’s liquid solution feeders fall into the category of positive displacement pumps, which means they rely on mechanically applied pressure, rather than suction, to push liquid chemicals — such as solutions containing chlorine, muriatic acid or soda ash — through their lines. The category of positive displacement liquid solution feeders includes peristaltic pumps, diaphragm pumps and piston pumps.

Peristaltic pumps move chemicals through a flexible feed tube, squeezing the tube with a rotating set of rollers and producing an output-side pressure that usually falls between 25 and 100 psi.

The mechanical simplicity of these pumps offers several advantages. “A peristaltic pump is completely self-priming,” says Kevin Boyer, COO of Aquasol Controllers Inc. in Houston. Boyer adds that a peristaltic pump also works quite well with gassing liquids like bleach, because its design simply pumps any gas, along with the liquid, right through the tube and into the line.

Diaphragm pumps move chemicals by rotating a cam or solenoid against a flexible membrane, displacing liquid while its egg-like shape applies varying pressure. As the diaphragm expands and creates a vacuum, a spring-loaded check valve at the pressure side of the membrane’s chamber opens, allowing fluid to flow in. As the solenoid compresses the diaphragm, the pressure forces a check valve at the chamber’s pressure-side out-port to open, allowing the chemical to flow into the feed line.

 
 

Piston pumps work in essentially the same way, except that the cam or solenoid pumps a piston, which compresses a similar flexible membrane.

Some diaphragm and piston pumps used to develop issues with gas buildup, which would cause the pumps to lose prime. However, many of today’s have designed their products to be self-venting. “Some of them are now built with a mechanism in the head that vents the gas back into the bleach tank,” Boyer says.

As designs of liquid feeders have improved over the years, their reliability and consistency have risen, and the amount of repair they require has decreased. Even so, a chemical feed system must be sized correctly, and matched with the right application, if they’re to be most effective.

Applications
Throughout the past several years, automation systems have become more advanced, and chemical feeders have grown less expensive — allowing a much wider variety of customers to incorporate chemical feeders into their projects. Today, some builders urge all their residential customers to incorporate automation.

“I myself will always recommend automation for residential pools,” says Troy McGinty, product manager at Hayward Commercial Pool Products in Rockville, Md. “And I’d say that every commercial body of water should absolutely have a chemical automation system on it.”

It’s also worth noting that many commercial clients will have already done some research into chemical feeders, and may have detailed questions about how these technologies can meet their needs. In short, it’s more critical than ever for pool professionals to understand which devices are most appropriate for each project.

As with electrolytic chlorine generators (ECGs), the ideal way to assess a pool’s chemical feeder needs is not by gallonage, but by the system’s demand for adjustments to chlorine, pH and so on. Environmental conditions, peak bather loads, and water loss or leakage issues are all major contributors to chemical demand. So it’s important to investigate these factors with the customer before making a feeder recommendation.

After establishing the pool’s chemical demands, the next step is to assess which type of feeder will most efficiently meet them. For many residential and small commercial applications, peristaltic pumps are sufficient. They tend to be less expensive than diaphragm and piston pumps, and a variety of size options are available — many manufacturers offer several tiers of motor size, and several feed tube diameters as well.

 
 

Diaphragm pumps are often better suited to large commercial applications because they’re typically designed to deal with more sizable chemical flow. Thus, they tend to be somewhat larger and more expensive than peristaltic pumps.

Also, instead of size variations, they typically deal with varied chemical needs by electronically limiting their output — a limit that may be imposed via an automation controller, or within the pump’s own circuitry, depending on the design.

In fact, automation controllers form a crucial component of many systems that involve liquid chemical feeders. Though some lower-end systems may simply use feeders to add scheduled doses of chemicals to the water, the preferred technique is to use sensors — such as ORP and pH meters — to communicate to a feeder array what chemical adjustments are needed. This sort of setup requires some automation components.

There’s also another impact of these automated adjustments — one that may be closer to home for many customers. “The biggest advantage of a chemical controller is that it’ll save you money on chemicals, because it’s not feeding you chlorine all night long,” says Gus Dabney, owner of Florida Chemical Laboratories in Largo, Fla.

Automated chemical feeders are particularly useful for customers who have electrolytic chlorine generators. Effective real-time monitoring control of the water’s pH and the chlorine levels will ease the burden on the salt cells, increasing their effectiveness and longevity.

Service
Though liquid chemical feeders can do their work without daily input from the user, they’re still subject to their share of potential issues. Frequent system checkups and adjustments — and part replacements when necessary — will go a long way toward keeping these devices efficient and trouble-free.

For a peristaltic pump, the most common issue is wear and tear on the feed tubes. This isn’t caused by any specific flaw in design; it’s simply due to the fact that the pump works by squeezing plastic tubes.

Another potential problem — especially with older peristaltic pumps — is clogging in the lines. Clogs can create back pressure that may damage the pump, so it’s also important to investigate this possibility on a regular basis. Thus, most experts recommend thoroughly checking the tubes of peristaltic pumps for leaks and clogs at least once per week.

In addition, it’s critical to test water chemistry regularly with a manual test kit, instead of trusting a readout on the feeder or controller. Over time, a film can build up over metal chemical probes, and this often skews their readings. Though a soak in muriatic acid or a scrub with a toothbrush will usually remove this film, the easiest way to know it’s become a problem is to “test the tests,” by comparing the system’s electronic readout with other test kit results.

Although some customers might hope that an automated liquid chemical feeder will bring an end to the days of constant maintenance, the fact is that any pool is a constantly changing system, and requires regular checkups and adjustments if it’s to stay safe and efficient. With that in mind, an understanding of chemical feeder mechanics will make it easier to anticipate issues, fix them before they become real problems, and keep the whole system running smoothly.

Source: Ben Thomas- Pool and Spa News | 10.28.2011

Lighting a Pool For Safety

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A commonly overlooked aspect of safety is proper lighting. Here are some tips.

 

When talking about safety-specific products, something that’s often taken for granted in the whole equation is lighting.

But this component allows swimmers to see where they’re headed and how far they can swim or dive before bumping into the walls and floor. In a commercial setting, lighting becomes even more important, as it illuminates signs and helps lifeguards identify when people are in distress.

But in the HMAC sector (hotel, motel, apartment and condo), this part of pool design is often done incorrectly. First, the owners of these facilities often have cost concerns.

“They’re the worst, because they don’t want to spend any money,” says lighting designer Jim Weathers, president of Engineering Associates in Alvord, Texas. “They don’t want maintenance items. They don’t want to spend $700 for a pool light; they want to spend $350 on a pool light, and they’ll put on the bare minimum. That’s all a cost game.”

A number of facilities also mistakenly use low lighting to set a mood.

But some counter that mood-setting shouldn’t be the priority. “It’s safety, not just paint it pretty,” says Kent Williams, president of the Professional Pool Operators of America in Newcastle, Calif. “It has to do with the survivability of the people who swim in your pool.”

Some facility owners and operators further say they want to minimize lighting to save on energy costs. But with new, energy-efficient options such as LED lighting available, that is no longer an excuse.

“You can justify improving your lighting if you can drop the cost of doing it,” says Alison Osinski, president of Aquatic Consulting Services in San Diego.

Here, experts offer some tips on properly lighting commercial pools and spas for safety.

Know the codes — and how they don’t apply.
Virtually all codes on the books contain lighting requirements based on watts, prescribing a certain wattage per so many square feet.

But these codes can prove to be outdated. For starters, lighting technology has greatly evolved since the 1970s and ’80s, when many of these codes were written. Today’s higher-efficiency lights yield significantly more illumination per watt and don’t require as much energy. These older codes don’t consider the actual light output, which affects safety more than anything.

The Illuminating Engineering Society makes recommendations based on the number of foot candles of illumination to be detected in certain spots. For instance, in indoor pools, a reading taken 6 inches above the water’s surface should indicate a light level of at least 100 foot candles. On outdoor pools, that measurement should be at least 60 foot candles. Illumination levels can be measured using a light meter or photometer.

Some state and municipal codes only call for 3 foot candles — well below that called for by the IES. But some professionals consider that too dark. “It’s low and just so out of industry standard,” Osinski says.

Many facility designers overlook light levels on the deck, which is important to ensure that signage is readable, Osinski adds. The IES suggests a minimum of 30 foot candles be detected at eye level on the deck.

Do not use lighting directly over the pool.
Some aquatic facilities will install lighting directly over the water — not on poles around the pool perimeter, but rather on rafters, catwalks and other structures reaching across the vessel. This is a bad idea for a number of reasons.

“It creates a serious glare problem for lifeguards,” Osinski says. “What they see is the light reflecting back at them. They see a perfectly round circle [of light] in the pool and absolutely nothing below it.”

And, with the potential for a bulb to shatter and fall in the water, this placement actually causes safety problems.

Finally, this kind of configuration doesn’t promote proper maintenance. “Every time I see one of those pools with the lights over them, I look up and about five of them are burned out,” Osinski says. “I say, ‘When do you change them?’ And I hear, ‘Oh, when half are burned out.’ That’s because it’s really hard to change the bulbs.”

Rather than placing lights directly above the pool, they can be installed on the perimeter and angled toward the water. This way, the glare is reduced and it’s much easier to change the bulbs.

Light the pool uniformly.
The goal not only is to help swimmers read signs and avoid hitting the bottom of the pool, it’s also to help rescuers see when someone needs help. “You want to be able to see a body underwater, or a person who’s in distress,” Weathers says. “The biggest problem I see is probably lack of underwater lighting.”

For this reason, installers should not rely solely on local codes to establish the minimum guidelines. Codes may require a certain number of watts every so many square feet, but this doesn’t take into account the beam spread and how much coverage the lights will provide. “When you do calculations based on square footage of surface area, sometimes you have dark places between fixtures,” Weathers says. “You need to space your fixtures correctly.”

On lazy rivers and other curvy, freeform aquatic elements, space the lights closer together than normal to make sure every inch is illuminated. “You get so much coverage from each fixture,” Weathers says. “Each one’s different, so you have to really look at the beam spread on the fixture and be able to triangulate that so you don’t have dark spots.”

Getting the best possible light may require designers to incorporate new habits. Especially in HMAC pools, many designers simply place one fixture at the deep end and rely on it to illuminate the whole pool. But the light beam will fade progressively the farther it travels, so the shallow end won’t be well lit. “What they should be doing is [placing lights] on the sides, all the way to the point where it becomes too shallow to install a fixture,” Weathers says.

For the shallowest water, such as that found in beach entries and sun shelves, designers should make special considerations. Most underwater lights can only be installed in water that’s 18 inches or more deep. In these spaces, add lights nearby, such as on pole-mounted fixtures.

“You can light them overhead with flood lights and still penetrate the water,” Weathers says. (But once again, these lights should not be placed on rafters or other structures crossing above the pool. Instead, they can be on poles around the pool perimeter.)

Pay attention to key areas.
Bathers use the shallow end more often than the deep, so make sure that area is well-lit. “We used to put six times more bulbs in the shallow end than the deep end, because the deep end has much less of the swimming activity,” Williams says.

Though the deep end may have two to three times more water than the remainder of the pool, he adds, the shallow end likely will hold the vast majority of swimmers. “So the shallow end needs a lot of light,” Williams says. “Any simple state rule saying you need one illuminator per 1,000 square feet isn’t sufficient.”

Additionally, make sure that drains are well-illuminated, so they can be easily seen for detection of missing or broken outlet covers, says Tom Ebro, a water safety specialist with Aquatic Risk Management in Lutz, Fla.

Use color sparingly, if at all.
If the goal is to detect the human form in distress as quickly as possible, Ebro says, it’s best to have as much contrast as possible. Thus, the ideal scenario is a light-colored pool interior with white light. Colored lights can interfere with quick recognition of a struggling person. In a commercial setting, avoid colored lighting.

Warn customers about maintenance and replacement.
Even when pools and spas begin with the right amount of illumination to meet codes and standards, time can erode that away.

“Part of the problem with lighting is you’ll go in and have a compliant situation with the [right amount of] foot candles, and over a period of time, the ballasts or light will get dirty, and you’ll go to less than [the needed] foot candles,” says Bill Rowley, president of Rowley International Inc. in Palos Verdes Estates, Calif. “Now you’re not compliant and you don’t know it. Then you’ll get into a situation with a lawsuit where you’re less than the [needed] foot candles, and even if it doesn’t have anything to do with the lawsuit, it will be cited.”

When completing a pool and “handing over the keys,” so to speak, designers and builders should warn owners and operators about the need to clean bulbs and ballasts, and to replace lights.

Explain to those in charge of maintenance that they should not wait until half the lights are burned out to begin replacing bulbs. This applies to in-pool lighting and other lighting in the area.

Inform pool owners and operators that too many burned-out bulbs can come back to haunt them if an accident occurs.

“If you don’t have enough light in a pool [so] that you can’t really perceive what the depth is, you haven’t got a chance,” Rowley says. “I’ve been involved in litigation where lights were burned out, which gave a false indication of the pool depth, and someone dove in and hurt themselves.”

Source: Rebecca Robledo – Pool and Spa News | 9.30.2011

Leisure Fiberglass Pools

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Leisure in-ground fiberglass pools offer a durable, low-maintenance alternative to concrete pools. Fiberglass designs tend to cost 10 to 12 percent more than those constructed from concrete or other materials, but they can actually save people money in the long run because far less will be spent on repairs and upkeep. In fact, at Expert Pools we offer lifetime warranties for the structure of our Expert line, and twenty-year conditional warranties on any cosmetic finishes. We also have several different financing options that make it easier for a person to handle the cost of a pool.

There are several fiberglass pool installers that serve customers in Illinois, Iowa, Ohio, Kentucky, Missouri, Minnesota, New York, Pennsylvania, Tennessee, Virginia, and Wisconsin but we feel our products are superior to those offered by other distributors. Expert Fiberglass Pools designs have 78 percent more flexural strength and 17 percent more tensile strength, and they are 33 percent thicker than the average fiberglass model. Our pools and spas are also on the cutting edge of technology, utilizing a unique closed beam coping that allows them to withstand the harsh weather across the country.

Fiberglass Pool Styles

Fiberglass pool styles and sizes are as varied as those of concrete and vinyl lined models. Large residential pools like the Moroccan  (16′ x 38′) or the Grand Elegance (16′ x 40′) require anywhere from 13,000 to 23,000 gallons of water and can be over eight feet deep ! Medium-sized designs like the Tuscany (14′ x 29′) and the Roman(12′ x 19′) range from about three to seven feet deep and generally use under 15,000 gallons of water. We also offer small and mini designs for smaller backyards and tighter budgets.

No fiberglass pool is complete without the proper accessories. That is why we offer top-of-the-line pumps, filters, heaters, and salt water systems. We can also install a host of other items such as fencing and power covers that will keep children and anyone else safe from harm.

 

L.E.D. Pool Lighting

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L.E.D. lighting can completely alter the appearance of a pool or spa and of an entire backyard. A splash of color such as blue, green, or purple can cause the shapes in the water to change in appearance, and they can affect the mood of all of those around the pool. That is why L.E.D. pool lighting is often the perfect addition to any backyard party, even one that doesn’t involve swimming.

On a very practical level, L.E.D. lighting makes it much safer for people to swim at night. Even the best swimmers can run into problems when it is dark. If one’s depth perception is affected in the least, he can end up hurting himself. L.E.D. stands for light emitting diodes. There are 9 colors standard and there is no risk of electrocution because the light works on a 12 volt current. The electrical cost of this lighting is much cheaper than conventional halogen-(old fashioned) lighting. You will save hundreds of dollars in the lifetime of ownership.

Fiber Optic  Lighting

At Expert Pools, we offer standard L.E.D. lighting options. However, we can also outfit our pools with Fiber Optic lighting. This style can give a very natural look to the pool, reducing the neon-like glow that so many lights produce. Also, Fiber Optic lighting can be used to highlight water features and steps.

Whenever a customer visits our showroom, he will have the opportunity to discuss all of the lighting options with one of our staff. You can even see a demonstration of what effect the lighting will actually have on a pool. Even if you decide to forgo Fiber Optic lighting options at first, accessories can always be added at a later date.

Installing Brick Pavers around a Pool

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The benefits of using pavers are both practical and aesthetic, especially if they’re chosen and installed correctly.

Looking for a deck option that can ride out ground movement while offering stylistic flair?

Pavers may be just the answer. They come in all variations — from the basic model you might find at Home Depot to more deluxe versions that include weathered-looking tumbled pavers, concrete varieties with pebble and sea shells mixed in, or those cut from stone.

These pieces fit together into puzzles that vary in complexity from a grid pattern to intricate mosaics established by the designer. In between lay interlocking pavers, with a built-in decorative line.

Practically speaking, this material offers several benefits. Paver decks are less subject to cracking than monolithic slabs, says Irv Chazen, president of Miami-based Custom Pools. He uses them on about 75 percent of his projects. “Problems seem to have diminished when the pavers were used in place of concrete,” he says.

A paver deck has built-in joints throughout, so installers don’t have to try to predict where cracking will occur, says Dan Essig, president of Artistic Paver Manufacturing Inc., in North Miami, Fla. Essig, who also builds pools, adds that a heavy rain or ground movement can cause a piece or two to pop out, though they’re easily replaced. They also make for speedier installation, because the decks can be placed piecemeal. So you can interrupt the job during rain.

But like any product, pavers have their drawbacks. Some are very porous, making them rough on the skin and prone to staining, mildew, algae and even freeze/thaw problems when water gets trapped in the nooks and crannies. Pavers also may experience color variations from batch to batch.

A little forethought
If your client wants to use pavers, keep a few design considerations in mind.

First, make sure their choice is comfortable against the skin. After his clients select their favorite paver, Chazen has them walk barefooted on samples to make sure the surface isn’t too rough. “I tell them, ‘If you think it’s too coarse, then don’t pick it,’” he says.

Also in the interest of comfort, look for pavers with beveled edges, Essig advises. Individual pieces will lift slightly out of the ground from time to time. When this happens, beveled varieties are less likely to ruin the look or cause stubbed toes, because they lack a hard corner.

When choosing a product, keep the pieces to scale. Small to medium sizes work best for most homes. Reserve the largest pavers — say, 24-by-24-inches — for unusually large areas.

Smaller varieties also work best with smaller pools, because you can pitch them away from the vessel without having to cut around corners and contours. “When you come to a corner, one side might pitch to the right and the other to the left,” Essig says. “Paver doesn’t bend, so you can’t get it to pitch in two different directions. If you have a 24-inch paver, it could be difficult.”

Some manufacturers offer matching coping. If you choose this option, use shorter, narrower pieces when working with freeform shapes. They are easier to manipulate around the curves and require less cutting. When placed around a radius, thicker copings can spread too far apart at the edges, leaving large, pie-shaped joints.

Also consider the direction of the grid. If the pool will run parallel to the house, Essig recommends pointing the lines diagonally toward the vessel rather than perpendicular. “Either the house or the pool isn’t going to be perfectly straight,” he says. “If you run the [grid] straight to the pool, the paver cuts will show any imperfections in the house, the pool or both. But if you use a diamond pattern, or offset, you don’t see imperfections as easily.”

This is especially important with rectangular pools. Freeform decks allow a little more flexibility, because there’s no straight line to give you away.

You can also use the grid pattern to highlight architectural elements of the home, such as a living-room window.

If the brand your client prefers varies in color from batch to batch, try to order everything you’ll need at once, Chazen advises.

On the ground
Installing pavers isn’t just a matter of sticking them in the ground.

For one thing, the right preparation is crucial. “If the job is graded, prepared correctly and compacted adequately, you won’t have a problem,” Chazen says. Without it, the product can pop out, settle or move in the ground.

Stabilize the ground the way you would for a concrete deck. While grading the area — to slope slightly away from the pool, of course — make sure it is sufficiently compacted. South Florida, for instance, has a lot of organic material in the soil, which must be removed. Or, you may have to contend with an erratic clay. If that’s the case, dig out 4 to 6 inches of the problem dirt and replace it with an immediately self-compacting, well-draining substance such as crushed stone. Chazen uses a gravel that’s approved by the state of Florida for roadwork called SRD screenings. Different areas have their own stabilization soils, Essig adds.

Next, place a 1- to 2-inch-thick layer of sand over the gravel. This leaves a soft yet self-compacting bed on which to tamp the paver stones.

Finally, dig and pour a perimeter footing. This 4-by-4- to 6-by-6-inch footer outlines the deck and keeps it from separating from the pool. “It’s not what you’d call a structural footing,” Chazen says. “It’s just a little trench with poured concrete that prevents the outermost pavers from moving outward and developing spaces between the deck and the pool.”

Place the pieces over the sand bed, spacing them uniformly for even joints, Chazen advises. Next, pour a fine sand over them. Use a power tamper to secure the stones in place. The vibration will cause the fine sand to settle and compact between the pavers.

If you and your client have chosen a particularly porous type of decking paver, coat it with a sealer to protect it.

Source: Rebecca Robledo- Pool and Spa News | 5.28.2010