Category Archives: Construction

Thermoplastic Pipe Expansion

Swimming pool piping is design is notorious for including long straight runs of pipe.  For pools that do include long runs of straight pipe sections, consideration may be given to the use of expansion loops or mechanical expansion joints to accommodate thermal expansion and contraction.  The ASTM Standard 2774 references “Underground Installation of Thermoplastic Pressure Piping”. This ASTM Standard 2774 contains specific information on the topic of expansion in pool piping.  Expansion and contraction of thermoplastic pipe is typically due to temperature changes to either the surrounding pipe embedment materials or changes in the pool water traveling in the pipe system. When temperature changes of the thermoplastic pipe does occur, changes to the piping network in the form of elongation or contraction will occur.  Therefore, in piping networks where there may exist sections of the pipe that are straight and without bends, expansion and contraction of the pipe can cause failures in the system.  Swimming pool piping networks that include PVC pipe used in straight runs nearing 100 LF should take special consideration to the potential expansion and contraction of the pool pipe.  In these instances the design of the pool piping system should have the coefficient of expansion calculated for determination if design accommodations for the expansion and contraction should be included.

In cases where expansion and contraction will be significant, inclusion of an expansion loop or even a mechanical expansion joint can be installed.  A pipe loop is a relatively easy item to include within the piping network.   This pipe loop, or offset, can alleviate the bending stresses that can occur when thermoplastic piping systems experience expansion and contraction.  If expansion joints are required, a detail for the expansion loop may include a specific dimension for the offset lengths.  Mechanical expansion joints work like a piston allowing the pipe to elongate or contract within the pipe run.  The installation of mechanical expansion and contraction joints is critical, particularly cleaning debris (sand, rock, dirt) out of the moving parts.  If small particles come in contact with the mechanical joint mechanism the joints seal can become compromised.

In most instances a linear pipe runs without interruption of bends, joints or pipe size changes is not common.  However, in situations where conditions do allow long pipe runs, your design should pay special attention for need of expansion and contraction loops and mechanical joints.

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Epoxy Grout

Tile, known for its longevity, has proven to be the most durable finish for pool interiors. Selecting the material, size, shape and color of the tile is just one step in the process. Another consideration is the grout selection. Grout can influence tile appearance significantly. If you choose the right grout, it can blend perfectly with the tile color. Or you can choose a contrasting color to highlight the tile. But that also requires an outstanding tile installation. Selecting your grout can be a very important decision as far as aesthetics go. Additionally, there are two different categories of grout; cementitious grout and epoxy grout. Both options are viable solutions for tiled pools, but with certain design parameters, one typically will make a better solution for a specific installation.
Cementitious grout, otherwise known as sanded grout, has been the longtime solution for pools. The cementitious grout can be applied at either indoor or outdoor pool locations, its color does not fade or change and it comes at a lower cost. But this product has also been noted to have a greater likelihood of having issues down the road. There are typically two main causes of failure, with the first being pool water chemistry. The water chemistry often gets exacerbated in spas due to calcium and/or acid issues. The water will begin to leech minerals from the tile grout, which makes the grout will need to be replaced sooner. The other main cause of failure are tile dots. The dots, in Counsilman-Hunsaker specification, have been limited to where they cannot occupy more than one-third of the depth of the tile. The grout is not allowed to occupy the depth or surface area needed to fill the space between tiles. It should be noted that the dots can still be an issue with the epoxy grouts, but it’s not as likely.
Epoxy grout, a product that has become more widely accepted by the aquatics industry as of 2010, is finding its way on more and more pool projects. The epoxy product is known to last longer, but tends to discolor and typically be more expensive. There will usually be a 25%-35% premium, plus additional installation and labor charges. Applications where movement is critical, such as second floors, are ideal installations for epoxy grout. The grout can be used in outdoor pool applications in freeze-thaw environments, however, certain conditions must exist:
• There cannot be a high-water table
• The tile must be porcelain
• The pool should be winterized with water in it (not completely drained)
The exterior application also brings the concern of fading dark colors over time, darkening of light colors over time and in cases where high MVER/high water table exists, the drain rate of the pool water for maintenance becomes just as critical as the fill rate (nothing greater than one-inch per hour).
In project applications where the budget is limited or in the case where minimum trim tile is being installed, the cementitious grout can be considered as a value engineer option.

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.

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.