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!

Sunday, April 27, 2014

Glass Tile Mosaic Swimming Pool

Unexplained cracking of glass tile mosaics in a swimming pool or spa are more than likely an issue of recycled content or impurities in the glass.

Random cracking failures of Oceanside Glass Tile Mosaics.
Blend: Random Modular Enchantment Tessera 
(click on the image to enlarge it)

If your glass tile swimming pool or spa experiences random cracking in glass tiles, it is more than likely a manufacturing defect, than an installation error.

Unexplained failures of Oceanside Glass Tile Mosaics in a swimming pool
(click on the image to see the crack failures close up)

But how do you prove this?  

Mount the tiles on a sheet of 3/4 inch CDX plywood, following the proper cure times for thinset and grouts.  Place the plywood into the same environment as the cracking tiles.  Place a duplicate sheet into the direct sunlight.  Place a container (tupperware tray) of loose tiles into the same environments.

If the loose and mounted tiles randomly crack, then there is a manufacturing defect.  Additional testing will be required to determine the exact cause.

If only the mounted tiles crack, then there is an issue of thermal expansion.  The cracking is occurring because the tiles are constrained by neighboring tiles and grouts.  Laboratory testing will conclusively vet the cause.

If only clear mounted tiles cracked, then there may be an issue of the thinset heating up in the sun.  The clear tiles usually pass more IR light resulting in excessive heating of the substrate.  This circumstance will require additional laboratory testing to validate the hypothesis.

If you are thinking about installing glass tile mosaics into your swimming pool.. find out if the thermal shock testing of the tiles was performed in the mounted condition (installed and constrained) or loose.  

Loosey goosey is muy malo! 
(loose testing is very bad)

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Saturday, April 26, 2014

Cracks - Recycled glass tiles pools spas

The most frequent common denominator seen by expert witnesses when inspecting cracked mosaic glass tiles in swimming pools, has been the use of recycled glass as a raw material.

Beyond their control

Recycled glass is supplied to the tile manufacturers already ground up.  This ground glass is know as cullet.  The standards established by the recycling industry permit cullet to contain impurities.

The Glass Packaging Institute standards state:  "Some recycled glass containers are not able to be used in the manufacture of new glass bottles and jars or to make fiberglass. This may be because there is too much contamination or the recycled glass pieces are too small to meet manufacturing specifications.... This recovered glass is then used for non-container glass products. These "secondary" uses for recycled container glass can include tile, filtration, sand blasting, concrete pavements and parking lots."  

They are saying that contaminated cullet should be sent to glass tile manufacturers!

The processing of cullet attempts to remove impurities.  By their own admission, sifting, electromagnets and optical inspection does not remove the tiniest of impurities.  Small metallic particles are the most difficult to identify and remove.  Non-ferrous metals (stainless steel, nickle, copper, aluminum, magnesium, maganese) cannot be removed with magnets.  These very contaminates can be the very cause of cracking in finished tiles.

Chemical Balance

It is possible for tile manufacturers to chemically counteract the negative effects of some impurities, but not all - especially metals.

Metal Stones

Metal particles are referred to as "stones."  Over time, these stones change in structure.  These changes cause internal stresses within the tiles.  Eventually the stresses grow to the point where the glass cracks.  Microscopic in nature, they are virtually invisible to the naked eye and beyond the ability (or manufacturer's desire) to be detected.

Refractory brick commonly errodes from the walls of the kiln, and becomes a contaminate within the molten glass.  These are also called stones.  Future thermal changes to the tiles will cause cracking, due to the differential expansion of materials.

Recycled Glass - Warm Fuzzies and Headaches

Using recycled glass as a component of glass tile production lowers raw material costs and provides consumers warm fuzzies.

The probability of contaminates is too high and potential for failures too great, to justify the installation of recycled glass tile mosaics in a swimming pool.

There are many first quality glass tile mosaics on the market to select from, to even risk considering tiles utilizing recycled glass content.

Once tiles begin to crack, water will infiltrate and soften the thinset.  Sharp shards of loose cracked pieces of tile in a pool or spa pose a threat to bathers.

The cost to remove glass tile, repair the substrate and membrane and reinstall new tile is double the cost of a new fresh installation.

Roll the dice or make a sure bet... the choice is yours.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Friday, April 25, 2014

Swimming Pool Glass Tile Mosaics Thermal Shock Testing ANSI A137.2

There is finally a method prescribed for the testing of thermal shock resistance of glass tile mosaics - ANSI A137.2 - 7.9.  This first ever standard is a good start.  However, it is still a far cry from where the standard needs to go.

The ANSI A137.2, Section 7.9 Thermal Shock  standard was developed by a committee that consisted primarily of, none other than... glass tile manufacturers.  Anyone else see a potential conflict?

Set themselves up for success

Manufacturers submit samples of their products for testing to a laboratory of their choice.  There is nothing preventing the manufacturers from providing specially selected, inspected or treated glass tiles for testing.  These may include inspections, testing, treatments or materials that are not utilized in their normal course of production.

The testing procedures only subjects 5 loose tiles to ten thermal shock cycles.  Five tiles simply are not statistically representative of tens of thousands of tiles that may be used in a swimming pool.

The testing lab does not perform any follow up testing of commercially acquired tiles.  There is no subsequent verification that production methods are generating compliant materials.  Again, a self- fulfilling prophecy.

Not Real World Tests

The five sample tiles are tested in a loose state.  They are not tested in the state in which they will be used by the consumer - that is installed.  You know - mounted and grouted.

Mounting and grouting glass tiles places constraints upon them.  They are adhered to on the reverse by thinset.  They are also constrained around the perimeter by grout and neighboring tiles.  Under thermal expansion, they have nowhere to go, especially if the setting materials are too constrictive.

Thinsets vary by their tenacity and shrinkage rate.  Some thinsets have a very high sheer strengths.  Some thinsets experience excessive shrinkage, placing the glass under compression.  Some do both.

Grouts vary in compressive strengths.  Some are more flexible, others more rigid.  Epoxy grouts are more flexible than in years past, and should not be immediately dismissed (as in CTIOA report 2008-8-12).

How SHOULD they be tested?

Glass tiles should be tested in their mounted and grouted state.  The way that they are intended to be used.

Acceptable thinsets and grouts should be specified by glass tile manufacturers, only after successfully completing thermal shock and sheer testing.  

Yes, this may require multiple tests with various combinations of manufacturer's setting materials to find compatible products.  Nothing precludes a manufacturer from specifying only one brand of setting materials.  But, this method may require multiple tests until one is found.

In fact, the thermal testing should be combined with the sheer testing procedures.  The sheer test is performed in a mounted & grouted state.  

Prior to performing the sheer test, the tiles should be subject to the thermal tests.  Excessive expansion may loosen or crack tiles - which will then fail the sheer test.  A REAL WORLD test.

Self-Serving Standards

Until test standards are instituted with the intention and purpose of protecting consumers and not manufacturers, what is a specifier or contractor to do?

Have any proposed tiles tested, in their mounted and grouted state.  Utilize setting materials from one manufacturer, adhering to the ANSI specified thinset and grout cure times - prior to any thermal or sheer testing.

Glass tile mosaics are the most beautiful and luxurious swimming pool finish available.  Properly installed quality tiles should last you a lifetime.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Thursday, April 24, 2014

Swimming Pool Glass Tile Mosaic Cracking - Tile Edge Quality

Poor Edge Tolerances

There are many reasons why glass tiles crack.  The most common is damage to the tile - a chip, scratch or impact.  These traumatic events occur during the manufacturing, handling, shipping or installation process.

Manufacturing Processes

Glass tiles are made into small squares by a number of various processes.  Cast or pressed, individually cut or snapped are the three most widely used methods.

Cast Tiles
Cast tiles are created when molten glass is poured into molds, individually forming each tile.  The process may be inverted, when a cookie cutter style press stamps out individual and distinct tiles.

Cut Tiles
Cut tiles are formed by cutting the tiles from a larger sheet of glass.  The tiles are usually then re-fired in a kiln to relieve stresses imparted during the cutting process.

Snapped Tiles
Snapped tiles are a more rudimentary method of forming tiles.  These are made by one of two processes: 
  • a cookie cutter style mold presses the tile shapes into molten glass.  The cutter does not separate the tiles into individual pieces, leaving them connected by a thin layer of glass.
  • molten glass is placed onto a mold tray and allowed to cover the mold.  It is then pressed or allowed to fill the cavities.  The tiles are connected by the layer of glass that remained across the dividers.
After annealing, they are later "snapped" apart, creating the separate pieces.  The process of snapping imparts chips and stress along the edges of the tiles.  Unless the tiles are re-fired in the kiln, these stressed tiles are handed off to the consumer.

Hard to Detect

These chips and stresses are hard to detect.  Since the tiles are usually mounted on an opaque paper, inspections are difficult for the end user, if not impossible.

Resulting Cracks

The stress that concentrates around these imperfections from thermal expansion will cause the tiles to crack.  Because not every tile has these imperceivable flaws, the cracking will occur randomly and the manufacturer will blame the installation practices.

Paolo Benedetti - Aquatic Artist "Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Saturday, April 19, 2014

Random Cracking Glass Tile Mosaics Swimming Pool

Most of the time, cracking in swimming pool glass tile mosaics can be explained by poor installation practices or shoddy workmanship.  Other times the cracking occurs without rhyme or reason in random tiles.
Random Cracking

Random cracking of glass tile mosaics is rarely the fault of the installer.  It is usually the symptom of inherent stresses within the glass tiles.
(Click on an image to enlarge it)
Random cracks in Oceanside Glass Tile Mosaics

But, without a "before and after" inspection of those same exact cracked tiles, there is no way to say with absolute certainty that the glass is to blame.  So it will become a case of finger pointing and blaming each other.

(Click on an image to enlarge it)
Random cracks in Oceanside Glass Tile Mosaics
Pre-Existing Stresses

A consumer or installer cannot be certain that any individual piece of glass tile does not possess a preexisting stress or flaw from the manufacturing process.

The only way to be absolutely sure, is to inspect each tile prior to installation... Time consuming and costly for sure.

Failure to Inspect
I do not know of any manufacturers of glass tile mosaics that perform a visual inspection of every single glass tile, prior to shipment.  Again, it would be too costly and time consuming.  

I'm sure that there are computerized optical inspection systems that could be employed, but after all it is "only glass tile."  The cost simply does not outweigh their liability for a few cracked glass tiles.

Protecting Yourself

The best way to protect yourself prior to an after installing glass tile mosaics, is to closely follow the installation instructions.

Unmounted sheets from each lot, color and pattern should be stored in a safe, cool & dry location.  Should there ever be a suspected failure, these samples can be tested at a materials testing laboratory for thermal shock resistance and inspected for preexisting stresses.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Tuesday, April 15, 2014

Swimming Pool Designs Designer

Creative swimming pool designs for people with disabilities.


Design is the formulation of an aesthetic and functional plan that considers the human interaction with an object.

Where's the design?

When installing a commercially purchased hydraulic handicapped lift, where are the aesthetics and creativity?  Unsightly, obtrusive, invasive, obstruction and hazard are descriptive words that come to mind.  

The installation of a deck mounted handicapped lift on a commercial or public pool actually violates other codes, ones that require unobstructed access around the entire perimeter of the pool.

Thoughtful design keeps everyone happy

To remain code compliant with all of the various and conflicting codes, one needs to get creative.

Two easy solutions are transfer seat walls or ramps.  A beach entrance can easily function as an ADA compliant access ramp, provided that the slopes are correct.

A transfer seat is merely a wall of the pool that is free standing.  The pool deck is lowered 18 inches in relation to the pool coping.  A wheelchair bound person, merely transfers to this raised bench and swings around into the pool.

With a little thought, ugly pool deck mounted handicapped lifts are not required to remain compliant with the ADA.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Monday, April 14, 2014

Hillside swimming pool desginer

Preventing movement and cracks of hillside swimming pools requires expert planning and a well executed design.  It also requires specific data gathering before a design can even be started.

Topographical Survey

It all begins with a survey of the property.  The topography of the slopes must be determined, so that the proper setbacks can be adhered to.  

This will ensure that the structures do not slide down the slope or cause loads that may entice slope failure.

What kind of soils do you have?

Next, the composition of the existing soils must be determined.  The structural engineer will need to know if the soils can support the anticipated loads.

Defining the soils conditions will also assist in determining if the slope is on native soil, poorly or uncompacted fill (common in hillside housing developments), the depth of the topsoil or if the bedrock is just below the surface (making excavation or drilling difficult). 

The soils report will also advise if there are unusual conditions (e.g. high water levels, expansive clay soils, vertical sheer planes, fragile bedrock, earthquake fissures) that may require specialized engineering.

"Steeper equals Deeper"

A good rule of thumb for sloping lots is "steeper equals deeper."  This means that the steeper the slope is, the deeper the foundations will need to be.

This is because the building codes require that the lowest outside point of the structure maintain a prescribed horizontal setback to the face of the slope (in proportion to the height of the structure).

The setback requirements are greater for occupied dwellings than for swimming pools, decks and retaining walls.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa © 
You may contact Paolo Benedetti at: or at 408-776-8220

Thursday, April 10, 2014

Swimming Pool Designs Designer Bonding Pool Water

I was reading about a UL listed water bond - safe for NEC 680 compliance.  It's used for bonding the water in a swimming pool.  

A metal plate is installed in the skimmer and the bonding connection is ran through a hole drilled into the side of the skimmer.

Easily Compromised

However, the product is easily corruptible via everyday occurrences in a residential swimming pool.

When the flow of water into a skimmer is impeded, then the bonding plate is no longer in contact with the water in the pool.

The flow into a skimmer can be easily affected by a low water level condition or by a weir becoming askew (bumped by children, tangled by goggles, a bathing cap, leaves or a twig).

Or a vessel may become a neglected pool, where the water is allowed to drop a few feet, rendering the skimmer bone dry.

In any of these conditions the bonding to the pool water becomes compromised.

24/7 contact must be guaranteed

Regardless of where the water bond is installed, it must guarantee that there will be a 24/7 contact with the water.  Safety devices cannot be on sometimes, and operating other.  They exist for a purpose.  This is not open for debate.
Potential pool leak

Then there is the issue of drilling a hole through a vessel (skimmer or main drain sump) that is supposed to be watertight.

Anyone who has ever worked on domestic plumbing, an automobile or ever replaced an o-ring, knows for a fact that they fail.  Not if they will fail, but when will they fail.  Relying on some caulking and an o-ring to prevent leaks is asking for trouble.

When the o-ring or bonding plate decays due to chemical and salt exposure, how will they be replaced?  The bonding wire and retention nut are on the outside of the skimmer, encased in concrete.

Better choice

A better choice is to locate an in-line water bonding device that can be installed in the water path near the equipment pad. This way it remains accessible and serviceable.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa 
You may contact Paolo Benedetti at: or at 408-776-8220

Tuesday, April 8, 2014

Malibu Beverly Hills Swimming Pool Design Expert

Paolo Benedetti announces the completion of another commissioned swimming pool design project.  

This glass tile mosaic perimeter overflow pool, is situated in the mountains above Malibu, CA, overlooking the Pacific Ocean on the horizon.

(click on image to enlarge it)

The spa was situated below the pool, to take advantage of the views and privacy.

(click on image to enlarge it)

The blue glass tile mosaic interior was expertly installed by Jimmy Reed of Rock Solid Tile.
The exterior of the pool and spa were clad with Corten steel panels. 

Call us today at 408-776-8220 to commission your own unique architecturally designed watershape.  Commissions are currently being accepted nationally and internationally.

Paolo Benedetti - Aquatic Artist 
"Creating water as art."™ 
Aquatic Technology Pool and Spa 
You may contact Paolo Benedetti at: or at 408-776-8220