Thursday, July 10, 2014

Swimming Pool Design in Expansive Soil Conditions

Plan for the Worst Case Scenario

Whenever designing or building a swimming pool in expansive soils conditions, you must plan for the worst case scenario, says swimming pool designer and expert witness Paolo Benedetti of Aquatic Technology Pool and Spa at

This means that you must adhere to to the following procedures:
  • Obtain a Geotechnical report (soils report)
  • Have the structure engineered to withstand saturated soil conditions when the pool is empty.
  • Ensure that water does not collect around the outside of the structure.
  • Isolate the structure from the soils.

Soils Report

The structural engineer cannot possibly know how strong to design the structure if he does not know that characteristics of the soils.

The soils report will define the load bearing capacity of the soils.  It will also quantify the expansiveness of the soils.  From these criteria, the structural engineer can determine the strength of the structure.

Structural Engineering

Whether one uses generic or custom structural engineering, it must exceed the forces the soils will exert upon it (these are known as soils surcharges).

The structural engineering will define the thickness of the walls and floor; the size, placement and spacing of the reinforcement steel, PSI strength of the concrete and any special mix design requirements.

Custom engineering is always recommended, as the structural engineer will also review other potential surcharges (from buildings, slopes, snow, surf, wind, etc.).

Empty and Saturated Condition

The structural engineer will design the structure to resist surcharges when the pool is empty.  Why empty?  Because some day the pool will need to be drained to be remodeled or refinished.

And because the engineer cannot predict the condition of the soils when the pool is drained, he must assume that the soils will be fully saturated and swollen.

Keeping the soils dry

Installing concrete decks around the pool will help keep the soils adjacent to the structure dry. 
Drainage should be installed to prevent water from sheeting off of the decks and into the surrounding landscaping.  This will only force the water to seep back under the decks into the sand/rock base, defeating the intent of keeping the soils around the pool dry.

Placing drainage rock or drainage panels under or around the pool is fruitless, unless there is a means to discharge any water that collects under the pool.  This could be a drain to daylight (if there were a slope nearby) or a dewatering well with a sump pump in it.

Isolate the pool from the expansive soils

Another method is to reduce the surcharges around the pool from expansive soils.  This can be achieved by over excavating the soils and later back filling with non-expansive materials.  Of course this requires that the pool be built differently, since the concrete cannot be shot against the soils.

Sand bags, void forms or geo-voids can also be installed behind the reinforcement steel.  Properly braced, the concrete can be shot against these surfaces.

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

Saturday, July 5, 2014

Expert Swimming Pool Design Services

What services should you look for when seeking an expert swimming pool designer?

Someone with a proven track record of delivering gorgeous projects.A designer who is not first and foremost trying to sell you a pool.Someone with your best interest, both financially and aesthetically in mind!

Luxury Pool and Spa Design Services

We work with property owners, architects, pool companies, landscape architects, developers, contractors and other design professionals, to provide the level of support that they may require. We can provide:
Luxury Swimming Pool & Spa Water Feature Design & Construction

  • Conceptual design services
  • Review existing designs and plans
  • Provide energy efficient hydraulic designs, calculations, and schematics
  • Consult on water sanitization options
  • Specify support equipment (based upon reoccurring maintenance expenses, ROI's & efficiencies)
  • Controls, automation & systems integration
  • Perform material selections & mock-ups
  • Provide construction & bidding documents (to include all/part):
    • Project layout
    • Cross sections
    • Equipment pad/room layout (to scale)
    • Equipment room support facilities (electrical, ventilation, drainage, etc.)
    • Plumbing schematics
    • Lighting schematics (vessel, area, or landscape)
    • Low voltage electrical schematics
    • High voltage electrical schematics
    • Details & cross sections
    • Shop drawings
    • Structural engineering (based upon owner provided soils/geotechnical report)
    • Installation practices & methodologies
    • Material Specifications
    • Workmanship Standards
    • Erosion or dust control programs
    • Gray water collection & waste water discharge
    • Site drainage
  • Construction Management
    • Direct construction/build-out
      • Our direct contract, management and coordination
    • Outside contractor
      • Review bids & proposals
      • Assist with contractor selection
      • Supervise local contractor
    • Progress/Site Inspections
  • Feasibility Studies
    • Pre-Property Purchase
  • Existing pool facility conversion/remodel
  • Expert Witness
    • Construction Litigation
    • Failed pool structures
    • Vanishing Edge, overflow & hillside pools
    • Workmanship standards: masonry, tile, plaster & other finishes
    • General workmanship issues, construction tolerances and material testing
    • Standards compliance
  • Workmanship, installation, materials

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

Tuesday, June 24, 2014

Swimming Pool Designer Expansion Joints Expert Witness

International expert swimming pool designer Paolo Benedetti discusses pool deck expansion joints in his article Expansive Tendencies:

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

Wednesday, June 11, 2014

EXPERT - Swimming Pool Reverse Osmosis Water Treatment detrimental to plaster and equipment!

Today there is just TOO MUCH information available to people on the internet.  And people believe everything they read on the internet... remember the TV commercial "Here comes my boyfriend.  He's a French Model.  I met him on the internet ?"

There are companies marketing reverse osmosis water treatment systems to the swimming pool industry.  They are being touted as the solution to mineral fouling, waterline scaling and perfect water balance. 

Reverse Osmosis Water - Good and Bad

Reverse Osmosis water is void of all impurities, minerals and contaminates.  It is "pure water."  Many brands of bottled water are purified using reverse osmosis.  This is what makes reverse osmosis water so good to drink and cook with.

Because reverse osmosis water does not contain any minerals, it must be packaged in inert plastic bottles.  Domestic reverse osmosis purification systems are plumbed utilizing plastic tubing and faucets with ceramic seals.

If copper or iron pipes were used, then the reverse osmosis water would strip the minerals from the pipes in an effort to re-balance itself.  Eventually the walls of the pipes would get thin and begin to leak.  

Detrimental to Pool Surfaces and Equipment

This phenomenon of desiring to re-balance itself, is what makes reverse osmosis water bad for use in a swimming pool, spa or fountain.

When the mineral content of water in a swimming pool drops below prescribed levels, the water begins to seek a means to re-balance itself.  And it is NON-SELECTIVE as to where it will draw it's minerals from.

This means that your pool heater's copper heat exchanger, pool plaster or pump seals will all fall victim to corrosion and decay.

Mineral Levels Impossible to Monitor

Even if a reverse osmosis system was outfitted with a sensor to monitor the calcium and mineral levels, it would not serve any purpose.  


Because those sensors could not determine THE SOURCE of the minerals.  The reverse osmosis system would think that the water was balanced, but it would not know if it was using the calcium from the pool plaster, tile grout or masonry mortars.

Once the mineral levels get to the minimum levels and the surfaces begin to decay, the reverse osmosis system still thinks that everything is okay.  The decay of the pool surfaces and equipment will continue until the owners observe the non-reversible symptoms of degradation.

Reverse Osmosis - great to drink, bad to swim in.

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

Tuesday, May 20, 2014

Swimming Pool Expert Witness Consultant designer

Who can be qualified as a Swimming Pool Expert Witness?

A swimming pool expert witness is one who testifies in residential, commercial or resort swimming pools cases involving disputes of product liability/incorrect application, construction defects, negligence, wrongful death, injury or illness.  

A qualified swimming pool expert witnesses will possess an education and background in swimming pool design, construction, maintenance and operation.  Swimming pool expert witnesses include aquatic consultants, watershape consultants, swimming pool contractors, mechanical engineers or structural engineers.  The more diverse their training and background, the broader topics their opinions may encompass.

The testimony of swimming pool expert witnesses is governed in Federal Courts by Rule 702, Federal Rules of Evidence.  Rule 702 was established by the Supreme Court ruling in, Daubert v. Merrell Dow Pharmaceuticals:
“A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:
(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert has reliably applied the principles and methods to the facts of the case.”

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

Sunday, May 4, 2014

Wet Set method causes Glass tile Problems

Glass tile mosaics are without a doubt, the most beautiful finish available for swimming pools, spas and watershapes.  However, there are standards and procedures that must be adhered to, to ensure a successful installation.

Water behind glass tiles from wet set method

First and foremost, you should obtain SPECIFIC installation instructions from the manufacturer of the glass tiles.  They should specify which products they endorse and recommend for their tiles.  If the instructions recommend a generic white cement and sand blend, seek specific pre-mixed product recommendations.  You do not want to risk an expensive glass tile job on such flimsy instructions.

Know the applicable standards.  While the Direct Set (aka: wet set or two-step) method of setting tiles may be okay for some stone and ceramic tiles, it is not permitted for glass tile.  Some foreign manufacturers still recommend it.  But, the 2005 ANSI A108.14-A108.16 standards are very precise about the acceptable methods of installing glass tiles.  The Direct Set Method is not one of them.  It is fast and inexpensive - that's why installers use it.  But consumers pay with issues like those shown above.

The Ceramic Tile Institute of America (CTIOA) and the Tile Council of North America (TCNA) also endorse the ANSI standards (  These standards also have prescribed materials performance specifications and curing times for each phase of the installation.

While time consuming and labor intensive, properly installed glass tile mosaics will result in a spectacular finish that should last for generations.

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