Aquatic Technology Pool & Spa, "Creating Water as Art."™

Aquatic Technology Pool & Spa, "Creating Water as Art."™
Pools as an art form - the way it should be!

Thursday, November 10, 2011

Glass Tile Mosaic Pools, Spas & Waterfeatures - ONLY Use Quality Glass Mosaics

Having a glass tile mosaic infinity, vanishing, horizon, disappearing, knife edge pool, spa, watershape or fountain is all the rage... But Aquatic Consultant Paolo Benedetti of Aquatic Technology warns that buyers need to beware, as the marketplace is awash in shoddy materials and poor workmanship.

Cheap is not Good
When it comes to glass tile mosaics, there is no such thing as an inexpensive high quality tile. I have inspected over 40 projects that had some type of glass failure. I am personally aware of at least another 50 - people who, for whatever reason, chose not to hire me to evaluate their issue(s). They were kind enough to forward pictures, samples and installation images.

In every case, the defects were attributable to a combination of poor quality glass tiles. If questionable installation practices were employed, the problems only compounded themselves.

Glass tile mosaics from the home improvement warehouse stores, internet, close-outs or cut-rate tile contractors that sell for under $10 per square foot, are almost always to blame. A recent $20+ million dollar estate that I visited, had thousands of square feet of $2 per square foot glass tiles installed. Where's the mentality in that?

There are literally thousands of companies on the internet hawking glass tile mosaics. "Quality glass tile $4.99 / sq ft" reads a leading search results. Of course they're not going to say, "Cheap prices, Cheaper Quality Glass Tiles from $4.99 / sq ft," but they should!

Some of these vendors are actual manufacturers, while others are merely middlemen or distributors. Most people look at samples, and because it looks like a name brand tile, they automatically assumes that it is of the same quality. This assumption could not be further from the truth!

While we'd all love to have our surrounding done in the most lavish materials possible, the simple fact is that quality glass tile and it's proper installation is EXPENSIVE - VERY EXPENSIVE! I'm in the trades, and I don't even have a swimming pool lined in glass tile (though my spa is!).

Quality glass tile mosaics start around $15 per square foot and go upwards from there! A simple blend of Italian glass tiles mosaics can easily cost $20-40 per square foot. And, these blends are their standard blends, ones that they do routinely, already have the graphics computed and maintain in inventory.

Select a custom blend of tiles from their color palette and the cost can run $40-60 per square foot, depending on the colors & complexity of the blend. Choose ORO (24K gold leaf sandwiched between layers of glass) and the cost rises exponentially - upwards of $750 per square foot (depending on the current market price of gold).

Inferior Manufacturing Procedures
I've previously discussed the methods used by various glass tile manufacturers employ to reduce their production costs: firing temperatures, annealing, blending, raw materials, recycled materials, double firings and contaminates. So, I'm not going to discuss those again here.

Besides the shortcuts employed during the actual making of the glass, there are other means of reducing their costs. The lack of initial quality control, ongoing random quality control inspections & testing and the tracking production lots are the most prevalent. Many do not even possess testing facilities or employ outside laboratories.

There are a couple of methods of coloring glass tiles. The most common is the use of chemicals and oxides to actually change the color of the glass. Because the color is throughout the material, any chip or scratch will not change the perceived coloration. This is the oldest and most proven method of coloring glass and dates back to before the ancient Romans. The leaders in this field are Lightstreams, Bisazza and Sicis (,,

Applying a colored coating to the reverse of a layer of clear glass is the second most common method of coloring tiles. The best method of achieving this is to actually melt 2 layers of glass together, a clear layer atop a colored layer. The colored layer does not need to be thick. These tiles have a very contemporary look and a great sense of depth, as there is a layer of clear glass on top of the actual color. The layer of clear glass can vary in thickness, depending on the manufacturer. However, the thicker the tile, the greater the potential that each tile will contain inherent stress, that will cause the tile to crack in the future.

Another method of back coloring clear tiles is to melt a coating onto the glass. There are a few companies that have refined this process and manufacture a high quality product. Interstyle ( of Canada is one such company.

But, there are a lot of knock-offs that try to emulate the appearance of these products from these quality manufacturers. The most common is the of recycled glass and the lack of quality control Refer to my prior articles about the dangers of utilizing recycled glass - while it is "green" it poses a serious financial risk to the installer & purchaser!

An attempt to back color clear glass has been attempted through the use of hand painted, silk screened, or sprayed on paint type of coatings. Anyone with a brain can surmise out that these coatings are not going to stay bonded to the smooth glass surface for long.

Another inferior process is a glued on backing. Because none of these companies ever bothered to perform accelerated failure testing of their materials, they have no idea if the backing will stay attached to the glass tile. Many don't even know if the adhesives they use are even waterproof! Place these tiles into a submerged application such as a swimming pool and in a few years you'll have a delaminated mess. Sometimes the colored backing itself is water soluble. Okay for a back splash, but in a shower, bathtub, fountain, swimming pool or spa you quickly have tiles popping off or letting loose - sometimes in big sheets.

(Color backing on the left has separated, darker ones on right are still bonded. Dark thinset highlighted mesh backing.)

Spacing Mesh (aka: mesh backing)
Oftentimes as the backing begin to fail, the mesh backing on the tiles starts to become visible. This is most evident on clear or translucent tiles, since you can actually see through the entire tile. This exactly why quality manufacturers of clear or translucent tiles do not use mesh backings - they can show through the tiles - even without any type of failure.

The mesh backings are merely designed to maintain the spacing between the tiles during installation. They are not designed to adhere the tiles to the substrate. But a poor quality backing can cause bonding issues. Backings that are too large, do not allow for the 90% contact with the thinset that is required by the standards. Plastic dot backings are the worst of these offenders.

(Mesh covers a large percentage of surface, improper use of dark thinset highlights the mesh. Note: poor alignment of the grout lines).

Personally, I prefer paper faced or plastic film faced tiles. Once set into place, the facing paper of plastic film is removed - there is absolutely nothing to interfere with the tile's contact with the thinset. Over the years, I have seen countless ceramic, stone and glass tiles delaminating from projects because the mesh backing was glued on with a soluble glue. As the glue dissolves and releases, it also causes the thinset to lose it's bond - and the tiles begin to fall off.

The Solution ? Replace the Tiles
Chipping glass tiles from a swimming pool shell is one of the messiest and potentially dangerous jobs in our industry. Shards of glass fly everywhere. Though protective gear is worn, vacuums and pressure washers are employed, small invisible shards seem to spread everywhere. Inevitably barefoot people seem to locate every glass shard around the pool for months following a projects reconstruction.

Installation Costs
Proper preparation, waterproofing and installation for a swimming pool is presently running around $80 per square foot (retail). Contractors who do the installation themselves with trained crews can expect their labor and material costs to be around $55-60 per square foot.

If the project has a lot of details that require a lot of trimming of tiles around jets, fittings, stairs, or circular vessels (e.g. round spas or fountains), then expect to pay on upwards of $100-125 per square foot. Meticulous details take time. And time is money!

You should expect and receive quality... compare some installations below. You can easily spot the quality VS the hacks!

( Click on an image to enlarge it)


Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool & Spa©

Wednesday, November 9, 2011

Infinity Edge, Vanishing Edge, Negative Edge Pool Design Issues

A Pool with an Infinity Edge, Vanishing Edge, Negative Edge, Knife edge, Slot overflow, flooded deck, gutter, perimeter overflow... there are a multitude of names. But, they all share one basic premise... move the water from a catch basin (or hidden surge tank) to a visible vessel and create the illusion that it is overflowing one or more edges.

Sounds Simple Enough?

In every one of these pools there is a "dam wall." That is a wall that is supposed to be dry on one side & wet on the other - imagine the reservoir where you go water skiing. Some of these pools dam walls are 6-8 feet high, while others have low dam walls of only 4-8 inches high.

The other common element is that there is a catch basin for the water. Some have the basin attached to the pool, while others transport the water to a remote storage vessel. The remote vessels can be under the pool equipment room, adjacent to the pool, under the pool deck, a lawn or any place in between. There just needs to be access to the inside of the tank, so that the accumulated debris can be removed. I'll use the terms: storage tank, surge tank & catch basin interchangeably.

Common Problems

The most common problem that I see when consulting on construction defect cases, are surge tanks that are too small. There must be enough water in storage to (a) fill the pipes, (b) raise the level of the main pool so that it over flows, (c) complete the trip to the storage tank. Remotely located tanks usually have gravity lines from the pool to the tank, so this is the "trip back to the tank" (as in c). All totaled this is called the "water in transit."

There must also be a "reserve" of water left in the bottom of the tank to prevent the drains from vortexing (swirling) and ingesting air. This can cause the pump to lose prime, eventually damaging the pump seals & bearing and allow water to enter the motor.

The second most observed problem is the edge effects system (drains, pipes, pump & filter). Usually there are not enough drains of a design that will allow debris to pass through. Instead leaves accumulate on top, restricting the flow starving the pumps for water. The plumbing is usually undersized for the line velocity of the water (feet per minute). The pump is usually WAY TOO BIG to flood the edge. And there is usually no filter on the edge pump. 95+% of the debris in one of these pools ends up in the storage tank. So, why in the world would you want to grind up the leaves, earthworms, salamanders and snails & spit them back into the pool?

Improper placement of the return lines can cause unwanted surface turbulence, destroying the glassy mirror effect that these pools are know for. The primary causes are due to high flow rates, placement in the walls, incorrect elevations and poor aiming of the return flow. There are very simple techniques to guarantee that turbulence will not be a problem, but you have to have this knowledge & employ the solutions during construction!

The next most common issue is with the dam walls themselves. Oftentimes incorrect construction techniques result in a wall with voids, allowing water to seep through. Poor waterproofing techniques can result in tiles that weep. Inadequate expansion joints in the material on the "dry" side of the wall can cause the material to delaminate. After all, isn't this material constantly going through wet & dry, hot & cold, and expansion & contraction cycles? They are after all usually exposed to the direct sun & wind.

Other fatal mistakes are the discharge of excess water and backflow prevention. Rainwater simply cannot be dumped on the slope below the pool - a foolish mistake. One that will surely cause a landslide or in the least cause the pool to slip or tilt. One cannot simply rely on mechanical check valves to prevent water from back siphoning to the equipment pad or catch basin. Check valves flutter and the seals get worn or tear. Face the facts - not if, but when it fails... One needs to rely on physics - something like gravity that is never turned off!

The "Goal"

The goal with one of these pools is to create the flooding effect with the least amount of water in transit as possible. A vanishing edge pool with an exposed catch basin IS NOT SUPPOSED TO FUNCTION AS A WATERFALL. That will cost you many more pumps and a W-I-D-E basin to catch the splash & splatter. The back side of the wall is supposed to appear as a "glistening wet wall."

If the edge tolerances are maintained (how level the finish workmanship is), then you will be rewarded with a pool that can be flooded with the smallest pump. If the pool is "dead on level" you could create the effect with a garden hose! Granted, you would need a larger pump to return the water to the pool displaced by bathers, but this is where a VFD (variable frequency drive) pump could come in really handy. It could run at low speeds to provide the normal visual effect. When bathers are present, it could ramp up the flowrate to meet the need of returning the bather displacement to the main pool.

These pools are spectacular to look at. While on the surface they appear simple, they are actually quite complex.

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool & Spa©

Tuesday, November 8, 2011

Caribbean Resort Knife Vanishing Edge Pools

Caribbean swimming pool designer Paolo Benedetti releases images of a glass tile mosaic resort project in the British Virgin Islands - Virgin Gorda.

2010 - Beach front construction on driven concrete piles.

Completed project - knife edges, 2 beach entries, and a vanishing edge.

Glass tile mosaic waterfall between the second and third tier pools.

Glass tile mosaic grotto and waterfall.

Close up of the glass tile grotto and waterfall.

Project Credits:
Location: British Virgin Islands - Virgin Gorda
Architects: Roger Downing & Partner Co. Ltd.
Developer/Contractor: Victor International
Swimming Pools: Paolo Benedetti - Aquatic Technology

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool & Spa©

Glass Tile Mosaic Infinity Edge Pool Design

Famous Vanishing Edge Pool Designer Paolo Benedetti, releases images of another stellar project.

Project Credits:
Architecture: Swat/Meirs
Construction: Silver Creek Development
Vanishing Edge Pool: Paolo Benedetti
Glass Tile: Sicis - Custom Blend

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool & Spa©

Monday, November 7, 2011

Glass Tile Mosaic Infinity Edge Pools

Famous vanishing edge pool designer Paolo Benedetti discusses glass tile mosaic pools.

It all about the glass!
Since a glass tile mosaic pools can consume a thousand plus square feet of material, everyone & his uncle are promoting their glass tile as suitable for swimming pools. They'll sell more tile for one pool, than they'll sell for showers and back splashes in an entire year.

But be forewarned, YOU GET WHAT YOU PAY FOR!

The cheap glass mosaics that you find at your local warehouse store are not suitable for outdoor applications, let alone swimming pools. Even worse, are the thousands of cheap Asian imports that are flooding the market.

Tile distributors and vendors in the United States, seeing the opportunity to make some money, have entered into private labeling agreements with these inferior Asian manufacturers. Some reputable furnishing companies have also put their names on some of these inferior tiles.

Almost no one from these United States companies has even bothered to travel to Asia to visit or inspect the manufacturing facilities. They have absolutely no idea how the tiles are made, the ingredients, whether the correct manufacturing procedures are being followed and the if there are even any quality control measures.

Limited Liability
In California for instance, a retailer is not liable if a product they sell is later found to be defective. That liability falls on the manufacturer.... do you see where this is going? The importer and retailer are free and clear!

You're going to have to sue the manufacturer in Asia to recover your losses when the tiles begin to fracture, crack, spall or disintegrate.

While you can sue the entities in the United States, they will claim that they have no control over the manufacturing process - hey, maybe that's why they don't want to go inspect the manufacturing facilities??? You think??

Poor Installation Practices
To top off the inferior tile, these Asian manufacturers are including installation instructions that do not meet international standard for glass tile installation (e.g. ISO, ANSI, TCNA, CTCA).

I was recently provided a set of instructions by a contractor in California, who insisted that the instructions included with the Chinese glass tile that he was selling were adequate. The Chinese instructions did not specify a leveling bed or waterproof membrane, nor did they even provide a list of tested and approved setting manufacturers. Their instructions said to mix "readily available white cement & sand" into a slurry paste to seal the concrete shell. A second coat of the same slurry was to be used to adhere the tiles to the pool shell. Finally, they stated that "any commercially available grout" could be used to grout the tiles.

Worse yet, the contractor ACTUALLY BELIEVED that this was adequate. And the homeowners and property owners he sold directly to bought into his horse & pony show.

If the going rate for the installation alone of glass tile is $55-$100 per square foot, then how can he provide and install glass tile for $20 per square foot?

Cheap inferior materials and inferior installation practices!!! Just follow the contractor's trail of unhappy customers and license revocations in other states!

I'd love to drive a Ferrari and only pay the price of a Yugo - but seriously, it isn't going to happen! Don't let your greed get the better of you!

Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool & Spa©

Vanishing edge, infinity edge, negative edge, knife edge swimming pool

From international swimming pool designer Paolo Benedetti, comes another beautiful vanishing edge/negative edge/infinity edge/knife edge pool.

A picture is worth a thousand words:

Design & Construction Consulting by Paolo Benedetti
Built by Paradise Pools

Paolo Benedetti
Aquatic Artist"Creating water as art."™
Aquatic Technology Pool & Spa©