Clouding and discoloration behind glass tile mosaics

With glass tile mosaics increasing in popularity, so have the complaints about dark spots, discoloration, clouding and color rendition.
 
Installation Practices

Proper installation practices for glass tile mosaics are time consuming and expensive.  The cost for labor and setting materials in a pool or fountain can run from $35-100 per square foot - not including the cost of the tile!

In an effort to bring the installation costs of glass tile in a swimming pool within reach of those with limited means, many installers take shortcuts.  These shortcuts include direct setting tiles, bonding them to incompatible substrates, using inferior setting materials or rushing the installation.

Published Standards

In 2005, in response to many consumer complaints and installation failures, the tile industry created minimum standards for glass tile installations.  This committee was comprised of glass tile manufacturers, manufacturers of setting materials and tile installation contractors.  The results were the 2005 ANSI Standards A108.14 - A108.16 - Practices for the Installation of Glass Tile Mosaics.

These standards were promptly adopted by the Ceramic Tile Institute of America (CTIOA) and the Tile Council of North America (TCNA).

In fact, CTIOA has since promoted the ANSI standards as the ONLY acceptable methods of installing glass tiles.  http://www.ctioa.org/pdf/2008-8-12_Glass_Tile_Report.pdf

Some third world and foreign tile manufacturers publish installation instructions that conflict with these standards.  Installation contractors need to be aware that failing to follow accepted and published industry standards will make them liable in the event of any installation failures.

The bottom line is that the installer needs to follow the most stringent standards that apply to their installation.  YES, that is even if a manufacturer allows for a faster, cheaper and easier method.

Trapped Moisture and Voids 

Moisture, voids or blemishes behind translucent (see through) glass tile mosaics will show through the tiles as a discoloration.  The discoloration can be spot behind a single tile, a random assortment of tiles or an entire installation.  They are unpredictable, occur randomly and may only affect a small portion of a project.

Voids, trapped moisture and blemishes occur behind the tiles from the following installation errors and mistakes:

• the bondcoat skins over before the tiles are set (poor bond, loose tiles & voids)
• using the improper direct bond (two step) installation method
• notches left in bondcoat
• too thin of a bondcoat
• utilizing dark colored grouts - which are visible through the sides of translucent tiles
• insufficient embediment into bondcoat
• too much water in the bondcoat 
• ground water weeping into the shotcrete from the soil
• grouting too soon after setting (the back buttering with grout method may in fact trap moisture)
• insufficient curing of the mortarbed (leveling bed)
• a bondcoat that experiences shrinkage (and results in voids)
• utilizing grey cements -which darkens when wet and will be visible through the sides of the tiles if allowed to ooze up between them
• failing to install a waterproof membrane
• filling the pool too soon
• failing to shade the tiles from the sun prior to filling the pool
• failing to protect the pool from rain (or snow or irrigation water prior) to filling the pool

I am not going to discuss each of the above conditions and why they cause discoloration behind the tiles.  Individually or in combination they can lead to visible setting flaws.

Testing

There are tests that expert witnesses utilize when investigating complaints of discoloration behind translucent glass tile mosaics. These tests analyze the visible color variations, composition of the setting materials, sheer strengths (pull off resistance) and moisture contents.

Samples removed for testing must remain in the same condition as when they were installed.  If they were under water, they must remain wet.  Allowing the samples to dry out will change the characteristics of the sample, rendering their evaluation useless in determining the cause.

Learning Process

The final result of any project evaluation, should be the education of the party responsible for the installation.  Incorrect installation procedures, improper setting materials or a combination of them, are responsible for most complaints of discoloration.  

Installers have been known to blame minerals in the water, airborne mold spores and poor pool water chemistry for causing these discolorations... anything but owning up to their misgivings.

Through strict adherence to the published installation standards and practices, you can be guaranteed a flawless glass tile mosaic swimming pool.

Contact the author, Paolo Benedetti of Aquatic Technology Pool and Spa at: 
info@aquatictechnology.com or 408-776-8220. 
Visit his website at: www.aquatictechnology.com. 
All Contents © Aquatic Technology Pool & Spa, 2013. 
All rights reserved.

Pool Expert Witness analyzes aqua azul colored glass tile mosaic failure

Swimming Pool Construction Defect Expert Witness analyzes aqua azul colored glass tile mosaic installation failure.

Something for nothing? Never!

A homeowner in Los Angeles, CA got competitive bids to line his swimming pool with aqua azul colored glass tile mosaics.  The average price for ONLY THE INSTALLATION was $75 per square foot.  The cost of the tiles would be extra.

However, one company proposed to supply their own aqua azul colored glass tile mosaics and install them for around $20 per square foot.

Hmmm...  multiple companies provided bids that averaged $75 per square foot (labor and setting materials only) and this company was going to provide and install the tiles for only $20 per square foot?  

Remember, there is a sucker born every minute!  You don't get something for nothing!

Poor Quality Glass Tile Mosaics

Yes, there is a difference in the quality of glass.  Most cheap imported glass tile mosaics from Asia are formulated with recycled glass of unknown origin.  This bastardized blend results in many kinds of glass with different expansion indexes.  Under the slightest change in temperature (sunlight or heating a spa) and the different formulations of glass will expand at different rates.  And,  you guessed it, they will crack.

This company promoted their glass as being inexpensive because they cut out the middleman and imported container loads directly from Asia.  

Poor quality glass is poor quality glass, no matter where it's from.  The contractor did not care, nor were they even educated as to the science of glass.  

                      Click on the image to see the cracked aqua azul glass tile mosaics up close.

Deficient Installation Instructions

The Asian manufacturer of the aqua azul colored glass tile mosaics did not even supply installation instructions that complied with ANY published trade standard.  Their instructions did not recommend any compatible thinsets or grouts. They made no mention of the requirement for waterproof membranes.  No Tile Council of North America (TCNA) product analysis or testing were provided or available.

Their instructions said to merely mix by hand, a blend of white cement and sand.  They stated to set the tile directly onto the concrete pool shell.  No leveling mortar bed and no waterproof membrane was specified.

TOTAL Disregard of Industry Standards

The low ball contractor then merely followed the manufacturer's instructions, and set the tiles directly onto the concrete shell.  In some instances, they merely set the tiles on top of the old pool plaster.

No leveling bed or waterproof membrane was installed.  The tiles varied in appearance because of the variances in the underlying layer.  The tiles were not level and undulated across the walls and floor.  

                 Click on either image to enlarge them, so that you can view this abortion up close.

No movement joint was installed below the coping stones.  The gap that was supposed to be filled with a flexible material was instead filled with grout.  When the coping exerted stress upon the tiles from thermal expansion, the energy was transferred into the tiles.

                                                Click on an image to enlarge the cracks!

 
Whose to Blame?

Legally, the contractor is ultimately responsible for the poor quality aqua azul colored glass mosaic tiles and the inferior workmanship.  There is absolutely NO EXCUSE for ignoring the published trade standards regarding the proper installation of glass tile mosaics in a swimming pool.  

A waterproof membrane is a "no brainer."  They are required in shower pans and showers are only wet for a few minutes at a time.  Swimming pools are full of water 24/7 and 365 days a year!
 
Greedy?

The property owner is to blame as well.

They were simply GREEDY and CHEAP.  They wanted something for nothing.  They wanted the look of the expensive glass tile mosaics without the associated price of doing it correctly.  

Lazy?

The property owner did not do their due diligence.  The search engine GOOGLE would have revealed that the contractor left Arizona, when their contractors license was REVOKED by the State of Arizona.  At the time, the State of California Contractor's Licensing Board records showed disciplinary actions and sanctions.  On-line reviews of the firm indicated that they were unscrupulous.

Yet the property owner hired them any way.  What a deal!  What an idiot!
 

                                   Click on the image to enlarge the delaminating tiles.

Instead they ended up with a nightmare.  But, they really got what they deserved.  This contractor and this property owner were made for each other.


Contact the author, Paolo Benedetti of Aquatic Technology Pool and Spa at: info@aquatictechnology.com or 408-776-8220. 
Visit his website at: www.aquatictechnology.com. 

All Contents © Aquatic Technology Pool & Spa, 2013. 
No portions of this blog may be reproduced or re-posted without the expressed written consent of Aquatic Technology.