Glass Tile Mosaic Swimming Pool Expert Wtness

Choosing a glass tile mosaic installation system.

Rule #1

Do it right or don't do it at all.

Beautiful, but Unforgiving

Glass tile mosaics in a swimming pool are the most beautiful glistening finish available.  However, they are also the most unforgiving.  An installer might have been able to get away with cutting corners with ceramic tile. But if they try to cheat with glass tiles they will surely experience installation failures.

Lack of Instructions

Many foreign manufacturers are trying to capture a portion of the US market.  However, they also fail to realize that we have published industry standards that specify how installations are to be performed.

When the instructions accompanying glass tiles lack specific product recommendations, then look to the manufacturers' of setting materials.  Many have developed complete systems for the installation of glass tile mosaics.

Choosing a System

Most high quality setting systems come with an installation warranty that covers labor and materials.  They will not cover inferior glass tiles.  

If you install cheap glass tile mosaics from a warehouse store, do not expect a warranty from the tile manufacturer.

Remember - you get what you pay for!

Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: info@aquatictechnology.com or 408-776-8220 "Creating water as art."™ 
Aquatic Technology Pool and Spa© ©www.aquatictechnology.com 
All rights reserved.

Swimming Pool Design

Why you need an expert swimming pool designer...

Value
A swimming pool designer will interview you and determine your needs, your changing lifestyle and your entertainment style.  They will plan and prepare your project for future modifications to accommodate those changes in the project's use.

Creativity
A designer can offer ideas and options that a salesman simply cannot.  If something is not on a company's menu, a salesman is not going to offer it.  Salesmen that attempt to deliver features that are out of their normal realm, more than likely they will not work properly.  I have seen a vanishing edge promised by salesmen to be a cascading waterfall, become nothing more than a spraying basin overshooting mess.

Money Savings
How can spending money on a swimming pool designer save me money?  Nothing is left for interpretation.  Thorough plans ensure that there is nothing omitted from the bids, that change orders are minimal and that the structural engineer has a clear picture of the intent.

Future modifications in the project, to meet lifestyle or use changes, can be incorporated.  This foresight can literally save you thousands of dollars by not having to rip out prior work that you paid good money for.

 
Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: info@aquatictechnology.com or 408-776-8220 
"Creating water as art."™ 
Aquatic Technology Pool and Spa© 
©www.aquatictechnology.com All rights reserved.

Glass Mosaic Tile Expert Witness Discolorations

You paid a pretty penny for the installation of glass tile mosaic in your swimming pool, spa, watershape or fountain.  Now you're seeing a discoloration behind the tiles.  

The installer it telling you that it's normal or from airborne mold spores during installation.  But you have doubts... and you are correct in your suspicions.

Source of Discolorations

Most discolorations are the result of installation errors.  They can be from any of the following installation mistakes:

• using gray cements or setting materials
• not keeping the tiles shaded until the pool is filled
• not protecting the work from rain or irrigation water
• allowing the bond coat to skin over (poor bond, voids)
• too thin of a bondcoat
• excess water in the bondcoat
• incorrectly using the direct set (two step) installation method
• leaving trowel marks
• grouting too soon (not allowing the bondcoat to fully cure)
• filling the pool too soon after grouting
• fielding mixing setting materials (results in unknown sheer and compression strengths, density and permeability)
• not using a waterproof membrane
• too thin of a bondcoat (allowing the membrane to shadow through)
• allowing ground water to soak through the pool shell

These are just some of the most common mistakes.  Individually or in combination, they can result in a beautiful pool turning into a hideous mess.

Industry Standards

Regardless of what the installation method your installer or the tile manufacturer recommends, there are acceptable industry standards.

Many foreign manufacturers are not aware that the tile industry in North America has performed significant testing and analysis if glass tile mosaic installation practices.  They have established acceptable methods of installing glass tile mosaics that apply to EVERY INSTALLATION in North America.  They are the GOSPEL for glass tile installations.

These practices are published under the ANSI A108.14, A108.15 and A108.16: Standards for the Installation of Glass Tile Mosaics.  They also make direct reference to the quality and performance standards for the required mortar beds, waterproof membranes, bondcoats (thinsets) and grouts.

The field mixing of mortar beds and setting materials cannot guarantee that they meet the ANSI performance standards.

Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: 
info@aquatictechnology.com or 408-776-8220 
"Creating water as art."™ 
Aquatic Technology Pool and Spa© 
©www.aquatictechnology.com All rights reserved.

Swimming pool bonding: A matter of Life & Death

Testing a swimming pool bonding grid

Required tools

An analog ohmmeter (meter with a needle, not digital). Available at Home Depot for $10.
A roll of wire (long enough to reach from the pool equipment pad to the furthest point to be tested)
Alligator clamps (attached to each end of the roll of wire)

Testing Procedure
STEP 1 - "Zero out" (calibrate) the meter:
Attach one of the ohmmeter leads to an alligator clamp that is on one end of the wire. Attach the other alligator clamp to the other ohmmeter lead.  The meter will display a measurement (it is measuring the resistance of the roll of wire).  Use the calibration dial to return the needle to zero.  You are now ready to start.

STEP 2 - Testing
Disconnect one alligator clip from the meter and attach it to an exposed bonding at the equipment pad.  Use the probe without the alligator clip to take readings of various metallic components, but touching it to them.  The needle should remain close to zero.
remember, if you are measuring the Ohms of resistance using the 10X scale, every reading is multiplied by 10 to get the true resistance.  There should be no need to use the 100X scale.

The following items should read zero ohms of resistance:

• Pool Heater
• Pool Pumps 
• Any piece of pool equipment that is metal
• Pool Controller (or time clock box)
• Related circuit panels
• The internal grounding bar of all pool light junction boxes.
• The external bonding lug of the light junction box.
• The metal parts of the diving board, slide, deck anchors, umbrella sleeve, fountain heads, spillways, waterfalls, etc.
• Anything containing over 4 square inches of metal that is within 5 feet of the pool (in any direction): downspouts, hand railings, steel in the pool deck concrete, window frames, skimmer lids, deck drains, pool cover tracks, pool cover lids, etc. 
• Swimming pool light niches can only be tested with the water removed from the pool.  When installed the stainless steel (SS) light fixture's face ring should read zero.  The following parts should also all read ZERO: 
• The SS straps inside of a plastic light niche.
•  The body of a SS niche.  

If these components show any resistance other than ZERO their bonding is corrupt.  More than likely the bonding wire is not securely connected or the continuity is broken between the niche, the junction box and the equipment pad.

BONDING is a matter of life and death.

Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: 
info@aquatictechnology.com or 408-776-8220 
"Creating water as art."™ 
Aquatic Technology Pool and Spa© 
©www.aquatictechnology.com 
All rights reserved.

Minimum Shotcrete Strengths Pools Watershapes

Shotcrete Strengths for Swimming Pools

The minimum compressive strength for shotcrete (wet mix or dry mix method) shall be 4000 PSI.  The minimum compressive strength of the concrete is fc’=4,000 psi with a maximum water-cementitious material ratio (w/cm) of 0.50.
  
American Concrete Institute
 

The American Concrete Institute’s ACI 318-08 Building Code Requirements for Structural Concrete includes Chapter 4 Durability Requirements. Also contained therein are two applicable tables:

Table 4.2.2 specifies the Requirements for Special Exposure Conditions. 

Table 4.3.1 Requirements for Concrete by Exposure Class defines a Category P1 exposure as concrete “in contact with water where low permeability is required.”   

American Shotcrete Association

The  American Shotcrete Association has also stated that their approved minimum compressive strength shall be 4,000 psi (as stated in the their Position Statement #1).

International Building Code

The IBC also specifies 4000 PSI shotcrete, by making direct reference to the ACI 318 standard.

The IBC (2012) 1910.6 Rebound Removal, also states that all rebound and trimmings shall be removed from the structure.

 

Therefore, all rebound, trimmings and loose debris shall be removed from the structure and shall not be used in any manner within the structure.

Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: info@aquatictechnology.com or 408-776-8220
"Creating water as art."™ 
Aquatic Technology Pool and Spa© 
©www.aquatictechnology.com All rights reserved.

Limiting Suction Outlet Plumbing Velocities

Standards Mandate the MAXIMUM SPEED LIMIT
 
Standards dictate that the MAXIMUM velocity limit in the plumbing at the suction outlets is 6 feet-per-second (ANSI/APSP-7).  I recommend that the maximum designed velocity on the suction side of the pump be limited to 4 feet-per-second.

Why lower that the maximum?  In suction lines speed is not a good thing.  In fact, excessive speed causes equipment wear, friction, lost energy and pump noise.

Since pump selection is the last task performed when designing a suction system, oftentimes there is not a pump curve that EXACTLY fits the system requirements.  By designing below the maximum allowed velocity, the designer has the ability to select the closest pump curve, even if it slightly exceeds the 4 FPS design - safely remaining below the maximum.

Isolation Valves 

When isolation valves are placed in suction lines between a pump and the suction outlets, any singular suction line supplying water to the pump MUST be capable of providing 100% of the systems’ designed flow rate at a maximum line velocity of 4.5 FPS.  

This is required, because if valves are closed and lines are improperly isolated, and if the pipes are not of sufficient diameter, the line velocity would quickly exceed the 6 FPS standard.

Energy Efficiency

Energy efficiency is greatly enhanced by lowering the line velocity.  Cavitation, operating noises & suction entrapment hazards are also reduced by lowering the line velocity.

Line velocities cannot be reduced much lower than 4 FPS, otherwise pipe scour would not occur.  Debris and sediment could eventually collect in the pipes.

Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: info@aquatictechnology.com or 408-776-8220 
"Creating water as art."™ 
Aquatic Technology Pool and Spa© 
©www.aquatictechnology.com All rights reserved.

Salt Water Pools Galvanic Corrosion

The current rave is have a "salt water" pool.  Many owners are under the false impression that these pools are "chlorine free."  Though, this is hardly the case.

Electrolytic Solution

Salt is placed into the pool to create a solution much weaker than that found in the ocean.  In fact there should only be about 3,000 ppm of salt present in a salt water pool.  A special device at the equipment pad, then splits the sodium chloride (salt) into CHLORINE!  These owners are merely using the salt to generate chlorine in their pipes!

But placing salt into the pool also turns the pool water into a electrolytic solution.  Add some stray current and the pool becomes in effect a giant electroplating tank.

A salt water pool is really a very weak, but giant battery!

Galvanic Corrosion

These stray currents will cause staining of the plaster surfaces, galvanic corrosion of less noble metals.  Copper heat exchangers will actually dissolve from the inside and decay on the outside, as their molecular structure is attacked.  Metals suspended in the pool water will bond to more noble metals, plating them in unusual colors.

Sacrificial Anode

Many in the pool industry have drawn on "a solution" that boat owners have used for years - SACRIFICIAL ANODES.  HOWEVER, a SACRIFICIAL ANODE is not the placebo everyone is seeking. 

On a boat, a sailor does not care if the anode erodes, or if the anode's metals dissolve into the water (ocean).  The anode on a boat is a lot cheaper than the wiring, an expensive bronze prop or brass components.  It prevents the corrosion of the boat's precious components, by SACRIFICING itself instead. 

Placing a sacrificial anode in a swimming pool is doing the same thing as on a boat.  One is merely offering a SACRIFICIAL metal for the galvanic corrosion to attack, instead of the precious components.  It does nothing to address the actual cause - GALVANIC CORROSION.

So instead of plating surfaces with copper, you will be plating them with zinc or magnesium from the sacrificial anode.  The sacrificial anode will save the copper, but it will not stop the staining or plating of the stainless steel components.  That will now occur with the metal from the anode.  

This is exactly why anodes need to be periodically replaced - they are sacrificed.  And where those sacrificed metals go is out of your control!

The Source of Stray Current

The equipotential bonding grid does not prevent galvanic corrosion.  In fact, if there is stray voltage finding it's way to the pool through the property's CONTINUOUS GROUNDING SYSTEM, the equipotential bonding grid may actually be feeding voltage to the pool's metallic components. 

The bonding grid can actually function as either the electrode or cathode, depending if there is stray voltage present or if it is providing a path to ground (where the equipotential bonding grid and the grounding grids are cross connected - pumps, heater's, panel boards, etc).

For these very reasons, many pool builders that I know and I, have ceased installing salt systems.  We now promote "off-line" on-site generation of liquid chlorine from salt or tanks of liquid chlorine and then the controlled dispensing via a ORP/pH Controller.


Paolo Benedetti, SWD Aquatic Artist, Watershape Consultant, Expert Witness, International Construction Management 
Contact the author at: info@aquatictechnology.com or 408-776-8220 
"Creating water as art."™ 
Aquatic Technology Pool and Spa© 
©www.aquatictechnology.com 
All rights reserved.