Category Archives: Construction

System Bonding for Water Slides

Proper pool bonding is incredibly important when it comes to considering the safety of swimmers. Pools require electricity to power certain components that make the pool function. Things like pumps, lights and heaters cannot operate without electricity. When pools and their necessary components are not properly bonded or grounded, some electricity can make its way into the pool and potentially harm swimmers. This is why Counsilman-Hunsaker ensures our standards are up-to-date and in line with National Electric Code (NEC) requirements.

Bonding involves electrically connecting all exposed metallic items not designed to carry electricity as protection from electric shock. What this essentially means is that bonding keeps electricity separate from swimmers. In an improperly-bonded pool, electrical gradients will seek the easiest path for conductivity. Bonded pools make electric currents flow into a grid that disperses them.

The requirement to bond and ground pools and pool equipment is a safety requirement incorporated into the NEC, specifically article 680. Equipotential bonding is intended to reduce the voltage gradients in the area around the pool by use of a common ground bonding grid in accordance with NEC 680.26.

The pool shell reinforcing steel, including at least three-feet of the perimeter deck, and all metal anchors, inserts, fittings, light niches, and equipment in the pool and within five-feet of the pool’s edge, as well as the mechanical equipment in the filter room, must be bonded together per NEC Article 680 to form an equipotential bonding grid. Further, due to the importance of controlling electrical currents in and around the pool, the bonding system should be taken back and connected to a positive, true and adequate ground. The ground should be tested and certified as a condition of acceptance.

The code does not specify with regards to water slide components that are beyond the five-foot perimeter around the pool. Water slides have a variety of components including the fiberglass flume, support structures, and the start tower. The water slide start tower and support structures are typically metal structures and, despite not being in direct contact with the water, must be bonded. The start tower is easily within reach of those entering the water slide start tub, and leaking water slide joints may provide a direct connection to the water slide support structure.  Thus, there is a need to bond these components with the rest of the pool components. Water slide manufacturers typically show these requirements on their engineered documents.

Ultimately, by properly grounding and bonding your pool components, you make your pool safer for everyone to enjoy. Swimmer safety is a top priority for Counsilman-Hunsaker, which is why we take these NEC requirements very seriously and regularly ensure our designs create a safe environment for everyone.

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Pool Chemical Room Recommendations

One of the specialty areas of aquatic facilities is the chemical room. These rooms are areas of the facility that are subjected to aggressive materials and more restrictive building code requirements. The International Building Code (IBC) describes a high-hazard occupancy as one “that involves the manufacturing, processing, generation or storage of materials that constitute a physical or health hazard in quantities in excess of those allowed.” High-hazard group occupancy ratings may require sprinkler systems, non-combustible floors, storage containment requirements and fire ratings.

 

Facilities that include a large body of water or more than one body of water can easily exceed the exempted quantity of chemicals allowed in the code. Designating the pool chemical storage rooms as a high-hazard group (H-2 or H-3) occupancy rating will allow for larger quantities of chemicals to be stored.  Chemical storage requirements are a function of the type of chemical stored. Anticipated pool chemical usage should be reviewed against available storage with a minimum storage quantity covering one week of use.

 

Common pool chemicals include the following:

  • Sodium Hypochlorite (liquid chlorine) is classified as an irritant with a sodium hypochlorite concentration of less concentration of less than one-percent. It is non-flammable and low in hazard. Some codes limit storage to 500 gallons or 1000 gallons.
  • Calcium Hypochlorite (table chlorine) is classified as a corrosive class three oxidizer. It is flammable and high in hazard. Some codes limit storage from 2 to 200 pounds in a single location. If this maximum quantity is exceeded, this space will need to be classified as a high-hazard group H occupancy.
  • Bromine (BCDMH) is classified as a corrosive, either class one or class two oxidizer. It is not flammable in and of itself, but it may ignite combustible materials in which it comes into contact. As such, it is identified as a hazard. Some codes limit storage to as much as 1000 to 4000 pounds in a single location. Typically, occupancy fire ratings of the room in which it is stored and used is two hours. Some jurisdictions may require that the space be provided with a qualified and approved sprinkler system. Additional storage of Bromine can be provided in a high-hazard group H occupancy room if the building has such a room.
  • Muriatic Acid (hydrochloric acid) is classified as a corrosive. Muriatic acid is highly reactive liquid acid. It must be stored separate from oxidizers and in a well-ventilated space. The IBC allows for up to 500 gallons of a corrosive to be stored and used before needing to reclassify the storage space as high-hazard group H occupancy.
  • Carbon Dioxide (CO2 – carbon dioxide liquid) is a liquefied gas which is colorless and odorless. CO2 must be stored in accordance with all current regulations and standards. The stored space should be well-ventilated.

 

Every pool chemical room requires mechanical ventilation at a minimum rate of one CFM per square foot of floor area over the storage area, as stated per IBC and IFC or 10 air changes per hour, whichever is more restrictive. Confirm with local codes and regulations if more stringent standards are required. Fumes and vapors shall be vented with exhaust taken per IBC and IFC recommendations. Return inlets for chlorine rooms shall be located low in the space as chlorine vapor is 2.5 times heavier than air and sinks to the floor, and return inlets for muriatic acid shall be high as acid vapors rise. In cold weather climates, heat must be provided to keep the room at a minimum temperature of 40°F to prevent freezing.

 

Understanding the challenges and provisions associated with pool chemical rooms allows for the proper design and construction of these specialty areas. Although these rooms are a small area of the facility, they are subjected to the harshest conditions. Typically, if a facility has great-looking chemical rooms, you can be sure the rest of the facility looks great too.

 

Depth Markers and Warning Signs

Depth makers and warning signs are one of the most important aspects of pool design. Depth markers and warning signs allow swimmers on the pool deck, as well as swimmers inside the pool, to know water depth. Knowing if the water is of a safe depth is critical information for swimmers looking to dive in.
In the United States, every state has its own health code with a standard approach on depth markers and warning signs, and how they should be placed in and around the pool. With that being said, Counsilman-Hunsaker implements its own standard when it comes to the layout of depth markers and warning signs on our pool designs. This standard is one that complies with all state health codes in the country, as well as the Model Aquatic Health Code.

Counsilman-Hunsaker’s standard states that all depth markers and warning signs on the deck shall be either slip-resistant tile or epoxy paint. It is expected that pool decks will end up getting wet, and wet tile can be very slippery. The slip-resistant tile and epoxy paint helps to prevent swimmers from taking a spill on the pool deck.
These deck markings should also be in contrasting color to all surrounding field tile. If the deck markings are the same color as the field tile, they can become camouflaged and overlooked. To keep this from happening, we have the contrasting color specification so the water depth number is clearly visible to all swimmers.
Every state has its own spacing requirements as far as depth markers and warning signs go, though the majority require both to be placed every 25 feet. Some states require that depth markers only need to be placed at the shallowest and deepest points and at every break in slope, while there are more stringent state codes that require the depth markers to be placed at the shallowest, deepest, every break in slope, and at every two feet of change in water depth. To keep all 50 states satisfied, we follow the most stringent codes when placing our depth markers. Depth markers are placed every 25 feet, at the shallowest and deepest water depth, at every break in slope, and at every two-foot change in water depth. Warning signs are also placed every 25 feet from the five-foot break to the shallowest point of the pool. The only thing left for us to do is adjust the placement from 25 feet to 20 feet depending on the local state code for the state we are working in.
As for the “No Diving” warning signs, 49 states require them to be placed from the five-foot break back to the shallowest water depth of the pool. New York is the only state that requires the warning signs to be placed from the eight-foot water depth back to the shallowest water depth.
Being aware of the various restrictions associated with depth markers and warning signs is vital to ensuring the safety of pool-goers everywhere.

Expansion and Contraction in PVC Pool Piping

In the commercial swimming pool industry, the overwhelming choice for pool piping material selection is Polyvinyl Chloride (PVC). The use of such materials can provide security, as it is non-corrosive, and if installed properly, some would say this pipe material can provide an almost infinite life span. But, in comparison to other pipe material selections, such as cast-iron, ductile iron, steel and concrete, PVC has a much higher coefficient of thermal expansion. This coefficient considers the amount of expansion or contraction that will occur due to the temperature range your pipe will endure and the length of pipe you are calculating. Thus, the design and installation of PVC pipe must consider how to accommodate such changes in pipe length.
For pools located in areas with seasonal temperature changes that utilize long runs of straight pipe sections, consideration should be given to accommodating expansion and contraction of the pipe. The ASTM Standard 2774 Underground Installation of Thermoplastic Pressure Piping, contains specific information on the topic of expansion and contraction in pool piping. A science-based formula for determining the expected change in pipe length due to expansion and contraction is:

By knowing the amount of expansion or contraction that will occur in your piping system, you can adjust the design as needed. These accommodations can range from changes in vertical or horizontal direction of your piping system, to the use of mechanical expansion and contraction joints. Changes in pipe direction using expansion loops, offsets and bends are ways to accommodate the expected changes in pipe length within your system. Considering that pool piping systems often have changes in direction due to the inclusion of supply inlets, main drains and feature supplies, the design and installation of the underground pool piping system naturally accommodates expansion and contraction. However, there are times when pipe runs become quite lengthy without changes in direction, and considerations for the inclusion of an expansion loop or mechanical joint will be needed.

Mechanical expansion joints come in many different types. Their primary purpose is to provide a means of flexibility in the piping network for expansion and contraction. They often work by allowing the pipe to slide into or out of itself like a piston. Installation of mechanical expansion joints for underground piping is critical. If the mechanical expansion joints, along with the materials used for backfill around the joints, are not properly installed, the effectiveness can be compromised. For example, backfill materials can make their way into the mechanical joint and hamper pipe movement. If backfill materials are a concern, it is recommended to boot the joint for protection.

In most installations, the straight pipe runs are not excessive enough or the design of the piping network will already include many bends or turns in the pipe. However, for those occasions where environmental factors result in expansion and contraction of pool piping, or straight pipe runs 100 feet or more exist, the design and installation must have allowances for the changes in pipe length that will occur. Without these provisions, the underground piping will be susceptible to potential damage, which will result in leaks to your pool piping system.

Springboard Diving

As a full-service aquatic consulting firm, we strive to design facilities that meet the needs of all user groups. While many aquatic sport facilities revolve around competitive swimming, we certainly do not want to neglect diving. While most university and high school teams only have 5-10 divers on their roster, they can be a secret weapon to propel a team over the competition. For instance, Purdue University finished in 13th place at the 2017 NCAA Championships with a final score of 106.5. The Boilermakers, Purdue’s diving team, scored 94.5 of the total 106.5 score for Purdue. Without the diving team, Purdue would have finished tied for 32nd place. Clearly, consideration should be given to a facility’s diving amenities.

Coincidentally, Purdue has one of the premier diving training facilities in the country, which includes a separate warm water diving pool with a massive 1-meter, 3-meter, 5-meter, 7.5-meter, and 10-meter diving tower. This facility has even attracted athletes like Olympic platform diving medalists Steele Johnson and David Boudia to train and compete at the university. While not every facility has the capacity or need for a platform as elaborate as Purdue’s, there are subtle ways to make your facility stand out when it comes to springboard diving.

There are two ways to mount a 1-meter or 3-meter springboard: on a stand or on a concrete platform. We tend to see a prefabricated, manufactured stand more often than anything else. These stands are made of heavy-duty aluminum and anchored to the deck using bronze deck anchors. The stands include handrails on both sides, as well as a ladder at the rear end of the board.

Shelby Bartlett, the four-time NCAA Zone qualifier and recently-appointed head diving coach at Saginaw Valley State University said that she prefers concrete platforms.

“They provide a more stable surface. Manufactured stands sometimes tend to shake, especially if they are older. And if the hand railings extend past the fulcrum, you can sometimes hit your hand on your walk down the board,” said Bartlett.

While manufactured stands are a good solution for low-level competition, Counsilman-Hunsaker has found that most high-level competitors prefer the more permanent solution that concrete platforms provide. These platforms also tend to be safer to travel up and down on.

Concrete platforms can be customized depending on the number and type of boards needed. Typically, we recommend providing two of each type of board to allow for multiple divers to practice simultaneously. Reinforcement for concrete platforms is designed by a structural engineer and is tested under both static and dynamic loads. A manufactured short stand is mounted to the concrete platform using bronze anchors and can come with or without handrails. If owners would prefer no handrails, they can be moved to surround the outside concrete platform to provide additional security on the elevated surface. This eliminates the risk of hands hitting the rails during divers’ approaches. In some jurisdictions, the concrete stairs leading to platforms fall under the design requirements of the International Building Code (IBC), which states that a maximum riser height for stairs is 7” with a maximum tread width of 11”. Both measurements are lower than that of most codes.

Counsilman-Hunsaker’s designed concrete stands have two intermediate steps bridging the elevation difference from the deck to the top of the one meter diving board surface.  There is a 10” riser difference between the deck and the first step, as well as between the first and second steps.  Between the second step and the top of the diving board, there is a 19-3/8” difference. Also, each step only has a “tread” depth of 4-3/8” at the deepest point.

While manufactured stands do not fall under the IBC, Counsilman Hunsaker can design custom stands to fit the gutter profile and meet requirements to provide a safer springboard experience.

Being leaders in aquatic design means presenting clients with all of their aquatic sport facility options. Determining the right diving amenities for you is just one of the many decisions we help make during the programming phase of design. Counsilman-Hunsaker has the tools to help guide your aquatic design to meet all user group needs.