Swimming Pool Rebar Clips - Expert evaluates suitability for swimming pool reinforcment steel

Not all products are suitable for their intended purpose.  Take plastic clips used securing reinforcement steel for instance.

Plastic is non-conductive


Because the plastic is not electrically conductive, the clips isolate the pieces of rebar from each other.  Why is this bad?

Electrocution.

Bonding grid



An equipotential bonding grid is required around all swimming pools and spas.  This includes ALL of the steel in the pool structure and surrounding concrete decks.

Non-compliant plastic rebar clips - cannot be used around swimming pools

Using plastic clips to secure the rebar, electrically isolates the bars from each other, defeating the continuity of the bonding grid.

Liability

Just because a salesman demonstrated their ease of use, and said that they were approved by the building codes, does not make it so.
If it cannot be proven that every bar is electrically bonded, then there exists a potential for electrocution.

This is exactly why epoxy coated rebar is not permitted for use in swimming pools - the epoxy (plastic) coating isolates each bar from the next.

Go ahead any use plastic rebar clips - if you want to pay to to remove and replace the entire pool someday.  It's your gamble...

Paolo Benedetti, SWD, Principal

Aquatic Technology Pool and Spa 
© http://www.AquaticTechnology.com 
International Aquatic Consultant, Watershape Engineering, Expert Witness, Hydraulic Designer, Landscape Design, Owner's Rep
Office: 408-776-8220 
Email: info@aquatictechnology.com 
Major Markets Serviced: 
San Francisco, Palo Alto, Atherton, Hollywood Hills, Beverly Hills, Malibu, Los Angeles, San Diego, San Clemente, Pacific Palisades, Escondido, Scottsdale, Seattle, Phoenix, Tempe, Portland, Aspen, Vail, Park City, Chicago, Dallas, Houston, Austin, New Orleans, Madison, Detroit, East Hamptons, South Hamptons, Cape May, Ft. Lauderdale, Orlando, Raleigh, Chapel Hill, Cherry Hill, Toms River, Salt lake City, Boise, Denver, Santa Barbaara, Carmel, Carmel Valley, Monterey, Pebble Beach, Oceanside, Big Sur, Napa, Sonoma, Sausalito, Danville, Belvedere, Montecito, Palm Springs, Midland, Manhattan, Greenwich Village, Osaka, Paris, Madrid, Barcelona, London, Seoul, Sydney, New York, Tokyo, Cairo, Istanbul, Athens, Rome, Lisbon, Bonn.

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.

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.