Miami, Florida Watershape Aquatic Consultant Swimming Pool Designer and Expert Witness

Smooth dowels should be utilized to transfer loads between adjacent concrete slabs.  This typically occurs where a pool deck abuts a building's foundation.

Required by Codes and Standards

The standards set forth by the American Concrete Institute (ACI) are incorporated in and adopted by almost every building code in the United States.

ACI 302.1R goes into great detail about the proper installation and requirements for doweling adjacent concrete slabs and foundations.

Freedom of Movement

Allowing the dowels to move freely within the slabs is one key requirement.  This is why greasing, smooth bars and sleeving are key elements.

Smooth dowels are similar in dimensions to typical deformed reinforcement steel (rebar), except that smooth bars do not have any ridges (deformations) along their length.  They are smooth...

Sleeving and greasing are two common methods to ensure that the dowels can slip freely within their cavities (when installed after one slab has hardened).

Dowel chairs (dowels supported on wire baskets) are commonly used when foresight allows their installation prior to the first concrete pour.

Cracking

The improper installation of dowels can lead to transfer cracking of either slab.

These are usually caused by the use of deformed bars, whose ridges grab within the drilled holes.
The transfer of stress, causes the bars to crack one or both slabs.  Not a serious problem on a patio, but it can be a problem with building foundations, slab floors, highways and bridge decks. Cracks allow water intrusion and possible corrosion of the reinforcement steel.  This is why most smooth bar dowels are epoxy coated.

Following the standard industry accepted methods and practices will prevent a lot of repair expenses later.

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.

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Expert Witness Swimming Pool Bonding Water

Bonding the water 
 

National Electric Code 680 requires that the water of the pool also be bonded.  This means that the water needs to be in contact  with the equipotential bonding grid.

This can be achieved if there is a properly bonded heater, light niche, bronze handrail anchor or metal umbrella sleeve underwater. 

Otherwise, a length of bonded stainless steel pipe or a bonding probe can be added to the plumbing at the equipment pad.

Bonding the surfaces around a pool

Section 680 also requires that the decking, or in the case of a deckless pool or one with concrete paving stones, that the soil surrounding the pool be bonded.  This can be achieved through the use of a copper mesh or a #8 copper wire that enciricles the pool.  The copper bonding loop must be attached to the pool’s reinforcing steel at four locations that are spaced equally around the perimeter. 

Your pool doesn't have rebar?

Vinyl liner or fiberglass pools that do not have reinforcing steel, must have a layer of copper mesh placed below them prior to installation.  This copper mesh under such pools must then connect to the decking loop in four locations, just like a concrete 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.