Monday, September 22, 2014

East Hamptons - Preventing Swimming Pool Deck Frost Heave Damage


What is Frost Heave?

More precisely it should be called "freeze heave."  When the wet soils become frozen, they expand.  These expansive forces usually go horizontally and vertically.

If the soils are constrained (surrounded by immovable objects) by a building foundation, retaining wall or swimming pool, they will push against those structures.  The weakest structure loses, and may experience structural distress.

Usually these forces  push upward, causing the concrete pool decks to heave or buckle.

An Ounce of Prevention

Proper preparation of the materials that underlie the concrete is key in preventing frost heave.

Preventing the underlying soils from becoming saturated, prior to a hard freeze is key.  Replacing the soils with drain rock, to a depth below the frost zone will greatly reduce soil saturation.

However, the water must be given a way to escape.  Perforated drain pipes, sump wells and daylight drains can assist as well.

Preventing water from running off of the decks and into the surrounding planters or lawns will also eliminate a lot of the ground water.  An 18-24 inch deep (or deeper) footing around the perimeter of the deck will also prevent irrigation water from seeping back under the pool decks.

Keep it Dry & Warm

Basically, the key is to keep the soils under the pool decks from becoming saturated.  Dry soils will freeze, but will expand minimally.  

Saturated soils will expand exponentially, causing cracked concrete (allowing water to seep under the slab), loose stone work and heaved pavement.  Well drained soils or gravel will not retain water & thereby not expanding sufficiently to cause damage.

Some success has been achieved with the heating of slabs and insulating the underside of the slabs.

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.

Sunday, September 7, 2014

International Aqua Design and Watershapes Consulting


With a background in swimming pool construction, design and operations, we deliver thoughtful designs with an emphasis on reducing reoccurring maintenance, operating and labor expenses.  A focus on the ROI drives our design decisions.... the REAL definition of VALUE ENGINEERING.

A few extra dollars spent upfront can bring a significant savings in maintenance, operating expenses, labor, downtime and ease future expansion.


Experience PLUS EDUCATION
 

Combining 20+ years of actual construction experience, watershape consulting, owner's representation, quality assurance, construction defects expert witness, a formal business degree and graduate courses in watershape and aquatic design - our background is unparalleled in the swimming pool design industry. 

We are not "self-trained," but are rather one of a few firms uniquely educated trained and qualified to design and engineer complex hydraulic systems and concrete pool structures. With a background in international consulting and as the owner's representative, makes us uniquely qualified in the entire world.

Educator and Published Author

Our founder has authored 100+ articles on such topics as swimming pool design, watershape consulting and construction defects.

He has taught courses on pool construction, waterproofing and aqua design to international audiences.

Uniquely qualified in all of the world - personal enough to be yours.

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.

Saturday, September 6, 2014

Aqua International Swimming Pool Design Consultants and Engineering

Whether your project is in Arizona, New York, Florida or California, the National Electric Code applies to your project.  And service disconnects are the most frequently omitted item on swimming pool projects and plan specifications.

NEC 680

Most people involved with the design or construction of swimming pools, merely focus on NEC Section 680, because it deals specifically with swimming pools and spas.  However by law, they are equally responsible for the entire contents of the NEC.

NEC 430.109(B)-(D)

The NEC requires a permanent means of disconnecting equipment for service purposes. 
The disconnect must be located on the equipment itself or within the line of sight of the equipment. 

Circuit breakers are referred to in the NEC as a branch circuit over-current protection device
According to the NEC 430.109(B),
branch circuit over-current protection devices shall not be used as the disconnection means for motors greater than ½ horsepower. 

For motors between ½ and 2 horsepower you cannot rely on the breaker.  Per NEC 430.109(C) you need a separate means to disconnect the power.

Variable speed pumps are a perfect example why we need service disconnects - they are wired so that they constantly have live power running to them - 24/7.
They are signaled to turned on and off via a data cable and not by way of switching the power on or off.  As is, the only way to turn off the power to the pump is at the circuit breaker.   But their nameplate rating is greater than 1/2 horsepower.
Therefore, that would be in violation of NEC 430.109(C).

The solution is to install an approved means of disconnection between the circuit breaker panel and the equipment.    

Section 680 of the NEC is not the only section that applies to swimming pools....  


Time to break out the NEC code and do some reading, isn't it ?!


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.

Thursday, September 4, 2014

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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Wednesday, September 3, 2014

Hamptons Swimming Pool Aquatic Consultant

Expert witness and construction defects consultant Paolo Benedetti of Aquatic technology Pool and Spa (www.aquatictechnology.com) discusses the importance of isolating the pool decks from the pool structure.

Independence

Independent movement is critical for the proper performance and protection of the swimming pool structure.

A 1/2 inch layer of closed cell foam should isolate the pool structure from the concrete deck and any stone or tile overlay.


Tying the pool structure to the pool deck with a few pieces of rebar or resting the pool deck on a ledge of the pool structure, will subject the coping and/or tile to horizontal stress when the decks move. 

A hinge effect is created where the pool deck is tied to the pool structure.  A few measly pieces of rebar will not prevent this hinging effect. Expansive soils can easily bend these bars and crack the pool structure.

This transferred stress will also result in cracked tiles, loose coping stones and a cracked pool shell.  This is usually evidenced by horizontal cracking within the top 6-8 inches of the pool, usually through the tile.  Loose and dislodged tiles soon follow.

Frost Heave and Expansive Soils

Deck movement can occur from expansive soils or frost heave.  The forces generated by these movements are enormous.


Cheap Protection

To protect the decks and any outdoor structure from such damage, it is a wise idea to place isolation foam everywhere the decks abut an immoveable object (planters, foundations, retaining walls, columns, pool structure, bbq, etc.).

To prevent water from getting into the joints, they should be sealed with an appropriate elastomeric sealer.  This help will prevent the soils under the concrete from becoming saturated from bather splash or rain water.

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.