In this industry populated by people, who have learned their craft by the seat of their pants, or from others who did the same, it is nice to know there is a place where quality workmanship and industry standards are actually taught. Dave Boyd, my business partner, and I recently attended such a school, so that when were are asked why, we would not respond, “that’s just the way we always have done it”.
David Tisherman and Skip Phillips with student
The school was taught by the renowned Genesis 3 Design Group. It is a joint effort by three of the finest pool designers in the world, David Tisherman, Skip Phillips and Brian Van Bower. It is the only pool and spa construction school in the United States that is accredited by IACET, the International Association for Continuing Education and Training. Genesis efforts, in offering this course as well as a number of other courses, that range from the technical aspects of the pool industry to designing the most artistic pools in existance, should be lauded. As a by product of their work, they have also created a network of designers and builders who are continually pushing the bar, setting the standards higher and higher!
In class with civil engineer, Terry Brannon
Having been in the industry for almost 20 years, first as a service professional, then as a pool renovator, designer and builder, I have seen first hand the poor standards most pool companies hold for themselves. It is a said fact these companies are not even aware of the standards set by fine organizations such as the American Concrete Institue or the Ceramic Tile Institue of America, let alone make their project specification adhere to their basic guidelines. Furthermore, I have previously attended certain trade association’s classes, and have been far less than impressed. With some associations, it seems they are more concerned with giving out ludicrous awards and patting themselves on the back, than in the delivery a quality product. It’s no wonder the pool industry has such a bad reputation.
Celebrating Success
Wanting to establish our company as above the average, we decided to complete the requirements of this course, which was followed by a thorough examination, given according to IACET standards. Both Dave and I learned a significant amount of information and were able network with a number of like-minded professions. More importantly, we both passed the examination. In the category of “tooting my own horn”, I was able to bring home the all time best examination score, and be quite proud of it!
By Eric Herman (written for Luxury Pools Magazine)
There was a time when swimming pools were relatively limited in terms of their aesthetic bandwidth. They were either kidney, rectangular, or lazy-L shaped, with white plaster, blue waterline tile, bullnose coping, and—if you were lucky—maybe tile mosaics depicting fish.
These days, however, that has changed completely. Swimming pools and the landscape elements that surround them can now be seen as a rapidly expanding architectural art form with a myriad of features, colors, materials, shapes, sizes, functionality, and stunning sculptural beauty.
As a homeowner considering this spectrum of creative possibilities and lifestyle benefits, the first thing you should know is…READ MORE
In our previous articles we discussed the design and layout of the pool, its excavation and steel reinforcements as well as the initial plumbing and electrical work. All of this work has been leading up to the single most important construction component, the shell of the pool, which surrounds the body of the pool. It is made of pneumatically applied concrete, shot at high speeds, encapsulating the reinforcing steel, to give remarkable strength. It’s quick to install, versatile, in that it can conform to almost any shape and compared to poured in place concrete is very economical. Yet without proper technique being applied at the time of the shot, the entire future of your pool will be problematic.
With all the preparatory work out of the way, the day has arrived when your new pool will be shot. The process is referred to as “shooting” because the materials are literally blasted into place at high velocity, over 100 mph, which is good! This “blasting” is part of the reason that the shell can develop such great strength. Other contributing factors will depend upon the type of shooting that will take place. There are two types. Although the names have been used interchangeable by some in the industry, which causes much needless confusion, both types are technically known as Shot-Crete or pneumatically applied concrete. With either type, the crews use air as the primary driving force which places, then compacts and consolidates the concrete mixture. The differences are that some crews use a dry-mix, commonly referred to as “gunite”, which is delivered from the trucks, forced through large hoses by air pressure, then combined with water as it leaves the hose nozzle. The other type of crew use a “wet-mix”, commonly referred to as “shot-crete”, which is combined with water prior to being pumped by a concrete pump through the hose, then is forced by air from the hose nozzle. For more information on the differences, read my article “Shot-Crete, Gunite what’s the Difference?”
Shotcrete Truck Setup
As the crews arrive, you will notice they are accompanied by several large trucks. The number of vehicles depends on which type of crew has been chosen. A wet-mix crew will arrive with at least a concrete pump and a large air compressor. They may mix the concrete on-site, which will require a vehicle to hold the raw concrete, another the aggregate, usually sand and pea sized gravel, and a mixing unit to combine these items with water. This is commonly done in area that experience high temperatures and are too far from a local concrete batch plant. As you may know, concrete, once mixed, must be placed within 90 minutes. So on-site mixing is sometimes their only option. A dry-mix crew will have a vehicle to hold their dry mixture and of course a very large air compressor. The larger compressor is required because the air is not only used to force the mixture into place, but to also move it through the hose. By contrast the wet-mix is moved through the hose by a pump, not air.
Below is a video of a wet-mix truck in place:
With the truck ready, the crews prepare the pool, confirming several key factors. First the pool must be level. Hopefully the previous crews properly leveled the work, the wood panels which outline the pool shape. If not, last minute adjustments must be made.
Second, the elevation must be correct. This measurement establishes a necessary reference point so that after all the work is complete, coping, tile, deck, etc, the finished product is at the appropriate level in relation to the house, or other buildings. Once the concrete has been set, “out-of-level” and “elevation” adjustments are much harder, if not impossible to make.
Third, the forms and steel are checked for sturdiness or rigidity, neither must be allowed to shake or otherwise move as the concrete is being shot. Vibrations and movements prevent the concrete from properly attaching to the steel and possibly create hidden voids, or pockets of air, which will weaken the structure. Insist that your builder provide adequate form work. A weak form will only hurt the process. If a spa is part of the plan, make sure the builder installs a form board between the pool and spa. Do not let them simply hold a “peg” board, or have it wired in place by bailing wire to the reinforcing steel. A solid form should be built. Once the wall which separates the pool and spa is shot and partially set, the form can be removed before the rest of the spa is shot. Failure to do so might mean a weakened mixture and voids behind the steel.
Fourth, they will confirm the thickness of the completed beam. Here the crews will confer with the builders plans to make sure the top of the pool wall, the beam, will be as thick as designed. Typically this is about 12″ wide. The importance of this cannot be overstated for two reasons. First, the beam must be sized as designed to allow for the later installation of finish stone work, and the allow the appropriate integration with any new decks, etc. Second, and no less important, the beam, and not just the beam on this point, must be wide enough in all places to properly “encapsulate” the steel. As we have all observed steel will rust, an normal process of oxidation when air, steel and water meet. Rust, although rarely good, is very bad in pool steel reinforcement. Particularly if the rust finds its way into the pool and shows itself as a dark red stain on the pool wall. In order to reduce and hopefully eliminate this process, the American Concrete Institute specifics where concrete is exposed to earth or water the steel should be encapsulated by at least 3″ of concrete. Unfortunately I have seen problem pools where the steel has only 1/2″ of concrete between the steel and the water. This problem can not be corrected later, only managed. It is a costly and avoidable problem, if the pool is shot correctly.
Setting the Guide Wires
To aid the crews as they are shooting, they typically install fine guide wires. The attached photo shows just such a wire, although the wire, being about the thickness of a piano wire is hard to see. Unlike poured in place concrete, which has forms forms on both sides, to contain the fluid concrete, shot pools have forms on only one side. Newly shot concrete is just shot is stiff enough to maintain its basic shape, so two sides are not needed. However, the guide wire helps the crew see where the “other” side of the concrete needs to be.
Partitions to Reduce Overspray
Other preparatory work includes placing screens to help prevent concrete over-spray from reaching the home or other structures. Concrete over-spray on a home would not be a good thing! There should also be a decision on what to do with the rebound and trimmings. Rebound is the term for the concrete mixture that bounces off during the shooting process. It is important to note that the “bounced” mixture is concrete poor, meaning it is usually the aggregate, sand, that bounces, most of the concrete that was part of the mixture will stick, making the rebound mostly aggregate. So rebound must not be reused. It should be collected and discarded. As a point of interest the dry-mix process always generates more rebound than the wet-mix process. A small amount of rebound is usually not a problem, but a large amount will have to be removed from the site. The mixture, though concrete poor, will still harden, and have to be discarded.
Troweling the Wall
The term trimmings refers to excess concrete, more being shot than is actually needed the crew will trim the concrete to the required shape, letting the trimmings fall. Trimmed concrete can be reused, as it is not concrete poor, however, it must be properly compacted and consolidated into place. Most crews find places in the floor for the trimmings. It is not recommended that trimmings be used in the cove, where the wall meets the floor as this is a structural stress point. This however is where trimmings typically fall. This requires the trimmings to be moved to a less stressful place on the floor.
Below is a video of a pool wall being trimmed:
With all the prep work complete the shooting begins. The long hoses, running from the truck to the pool, terminate at a nozzle, which the crew member, called the nozzle-man, aims the hose, directing the concrete flow. He begins at the cove, base of the wall and floor. The extremely important area, must be solid and well shot. The concrete is built up from this point making the walls, benches and other components. The floor is usually the last place to shoot. Sometimes the process will be stopped as the crews moves between the main pool and the spa, fountain or other structure. Always the nozzle-man maintains a flow at downward angle, moving back and forth building up the concrete toward the final shape.
Finished Shell
As mentioned earlier regarding trimmings, the concrete is built up to a level greater than needed, then trimmed back to the desired shape. The process requires patience and an ability to see shape of the final product. All the internal components have to be shaped, the steps, benches, love seats and shallow lounge area. In addition the pool fittings, where the plumbing penetrates the wall has to have special attention. At each location an indention is shaped around the protruding pipe to provide room for the “fitting” which will be installed later. The lights, skimmers and main drains will have similar attention. Finally you may notice one or more “weep” holes, voids in the concrete where ground water can move if excessive rain occurs before the pool is completed.
The entire process for a small pool should only take a few hours, obviously more for larger one. Large commercial projects can take several days. Prior to the shell, the shape of the pool can only be imagined, based only on the design drawings and the designers descriptions. Now, the shell having been shot, the pools shape becomes clear. One step closer to a completed pool!
In our previous articles on pool construction we have discussed design, required city permits, excavation and steel reinforcement. We are almost ready for shooting the pool shell. However we most consider that some tasks required in the construction of must be at least partially performed before the pool shell is built, namely the plumbing and electrical work. Both of these tasks will not be fully complete until much later in construction process. Yet where either of these tasks will penetrate through the pool wall, the must be laid before the shell is installed.
Skimmer Plumbing
The easiest explanation of the plumbing is built on the understanding that the water in the pool completes a circuit, which is known as the hydraulic system. It must first be pulled from the pool, filtered, heated if desired, perhaps even treated chemically, then returned to the pool. This process begins with the water being extracted through the skimmers and the main drains. The skimmers which mounted at the water level are designed to catch leaves and other floating debris which is collected in a basket. It is advisable to have more than one skimmer installed in your pool, particularly in environments with lots of foliage or on larger pools. Better pool designers and builders will insist on at least two skimmers on every pool and increase their number as the situation warrants. The exception to this is on pool designed with either a “vanishing edge” or a “raised perimeter overflow”. The vanishing edge pools have at least a portion, usually an entire side, where the water spills over the wall of a pool and into a trough or catch basin. Raised perimeter overflows are pools partially lifted out of the ground. Here the water spills over the entire perimeter of the pool, usually into a hidden trough which surrounds the pool. Both of these types of pools offer dramatic visual effects and usually have no skimmer. This is because the trough or catch basin often acts like a huge skimmer. These pools stay remarkably clean!
Main Drain Plumbing
The main drain, which is a misnomer, is currently the source of much saftey discussion. It really should not be called a drain since it does not allow you to drain your pool. Neither should it be considered the main source of water for your pool equipment, in that the equipment should only rarely receive all its water from these drains. Technically these devices are referred to as “suction outlets”. It is vitally important that the hydraulic system of any pool be designed with care. Recently congress passed the Virginia Graeme Baker Pool and Spa Safety Act. This law purpose is to reduce the danger of these outlets by requiring outlet covers pass strengant testing requirements and that outlet placement meet certain standards to reduce the likely hood of someone becoming entraped by these outlets. However there is no requirement that a pool actually have these suction outlets. Constructing a pool without them altogether will more than just lower the possiblility of a suction entrapment, but will compeletly eliminate it! The photo pictures placement of these suction outlets as currently required. If you look carefully you will notice that the installation has altered the steel layout which will have to be corrected before the shell is shot.
Wall Plumbing
After the water has been filtered and otherwise treated, it is returned to the pool via the returns fittings attached to plumbin which extends through the pool shell wall. Prior to the shell construction, the plumbing for these returns must be placed and secured into position so that they can not be moved as the shell is placed.
Electrical Bonding
A similar process must be completed for the electrical work. Codes require that the steel be tied electrically to the electrical system through a bond, which is a wire that runs from the pool equipment and to the pool structure and is tied in several places directly to the stell reinforcement of the pool. Since most pools are constructed with an underwater light the conduit for the light must also be installed at this time.
Later the more plumbing and electrical work will have to be completed. But with the inital work complete, specfically where there work extends through the pool wall, the pool is now ready for the next step, the shooting of the pool shell!
To review a FAQ (frequently asked questions) Report prepared by the Health Department of the State of Texas regarding the Virginia Graema Baker Pool and Spa Safety Act - Click Here!
It should be noted that not everything must be the same. Sometimes even simplest changes, such as the direction of the tile can make all the difference in the world. Doing so may add visual interest by emphasizing a new direction for the eye to follow. On a recent project we used a diagonal placement of tile to achieve a stunning look over what was a dated and overwhelming feel of the brick!
Brick can be a wonderful construction material, but in this case, the builder used too much brick. In dealing with an natural elevation change present in the yard. The builder created a wall, raised bond beam, to retain the soil of the yard, which sloped toward the rear entrance of the home. This raised area was now home to a spa, itself raised slightly, and a small entertaining area. This area space is accessed by a series of steps to the left of the spa. The wall began with the steps, ran underneath the spa and extended to the far side of the pool where it similarly descended back to the elevation of the home. For all of this the builder used a red brick, both as coping on the pool wall and as a face to the wall itself. The only exception being a vertical band of tile below the spillway of the spa. The effect of this much dark brick was to overwhelm, putting the entire backyard out of balance.
In approaching this project, our client asked us to update the pool’s overall appearance, especially the brick wall. To do so required numerous visits to various material suppliers until we found a coping treatment and tile selection that matched the clients taste while lightening the pools appearance.
After much searching and deliberation, we finally settled on a 6″ x 6″ light tan and gold tile, which came with wide variation in color for the pool water line and a matching 12″ x 12″ for the wall. The tile was complemented with 24″ bull-nosed travertine coping. Travertine was also used to create a new extended spillway.
Surface Preparation
The existing brick face was left in place, but was coated in mortar. In doing so we were creating a new tile beam, which is usually necessary in renovation work, but particularly in this case. Over this rough brick we needed a smooth and level surface for installation of the tile.
Centering the Tile
Our 12″ tile was centered on the wall between the water line and the spa spillway. The initial tiles set are the most important, as they establish the pattern for the entire wall. We chose to lay the wall tile on diagonals. This would create a simple but interesting pattern, which would contrast nicely with the lines of the pool.
Pattern Continued around Pool
The actual setting of these wall tiles was time consuming, requiring a number of cuts in the tile, particularly where the wall angled in and out from the pool. After the tile was set a topaz colored grout was applied. This color matched perfectly with the tile making the grout lines all but invisible.
Wall Tile and Spillway
Eventually the wall was completed along with the coping and water line tile. The effect new tile, particularly against the against the color of the water was visually stunning!
Right now everybody is trying to save money, and who could blame them? Everyone wants to make their money last, as long as possible. One way to do that is to reduce your energy consumption. With today’s rising energy costs, and their continued rise in the foreseeable future, it just makes sense to reduce when and where we can. There are new technologies available that help you do just that. A high efficiency variable speed pump may be just the ticket you need, to still enjoy your backyard pool and spa and yet save on energy!
Pentair's IntelliFlo-SVRS
This technology has finally made it to the pool industry after being developed for industrial uses and most recently in hybrid car technology. We will all be the better for it, as more and more designers specify these pumps in their designs. I specify them in all my projects. Why, because manufacturers claim these pumps can save from 30 to 90% over a single speed pump, if it is used correctly. It accomplishes these saving by in three ways.
The first is through a more efficient design. Pentair Water has led the pool industry through the introduction of their variable speed pump, the IntelliFlo. Although other pool manufacturers have introduced their own variable speed pump, in my opinion Pentair’s design is still superior. Prior to their new pump, all residential pool and spa pumps used a basic “induction” electric motor, which requires a portion of the electrical energy to be used in creating a magnetic field. This magnetic field is what propels the shaft of the motor to spin. In an induction motor this field is constantly shifting, keeping the shaft spinning at nearly 3,000 revolutions per minute. The energy required to generate this field and the inevitable heat that is produced in the process is a consumption of energy that need not be. In contrast Pentair’s motor uses rare earth permanent magnets, so there is no energy absorbed in creating this magnetic field. The motors, therefore, use less electricity even when running the same speed and carrying the same load as a similarly sized induction motor. A side benefit is the motors run cooler, which promotes a longer service life, which reduces the long term cost of ownership.
Pentair's IntelliFlo-SVRS Control Panel
The second is through understanding the Law of Infinity regarding energy. Most of us relying on “common-sense” would assume if we increase the output of a pump the energy requirement increases proportionally. Meaning, if you doubled the volume of water a pump pushed, the cost would be twice that of the lower volume. However, this is not correct. Simply put, the Law of Infinity states when you double the power output of a motor the energy requirement increases by a factor of four. That’s twice as much as what one would think. Conversely, and here is the real benefit to the motor, when you decrease the power output by half, you cut the energy requirement to 1/4 its previous amount.
Pentair's IntelliFlo Installed
The third is through using only as much energy as is actually needed. Prior to the introduction of this pump, the determination of which pump to use was a little like buying shoes. Shoes come in various sizes, but unless you had custom made shoes, you had to settle for a shoe that was either a little too small or too large. Rarely was there a perfect fit. Pumps were the same way, designers picked from the various pump size offerings without the benefit of a perfect fit. The IntelliFlo-SVRS version of Pentair’s pump has the capability of performing like a pump anywhere along the spectrum of a 1/4 horsepower output up to a three horsepower output. This allows the designer to install the pump and find that perfect speed which supplies all the necessary water to your spa and not a bit more. Once installed the pump can be programed with up to eight speeds in its memory, meaning you will have up to eight pumps in one. So one could program a very low, barely operating speed for maximum energy saving, and in addition several higher speeds could be programmed to create a visual effect from a water-feature. The pump has a built in timer, which when programed, allows the pump to automatically switch between these speeds.
Installing the IntelliComm Interface
One draw back on the pump is that utilizing the display requires bending over to see and adjust the display mounted right on top of the pump, which is often not very convenient. However, the pump is easily controlled by any of Pentair’s automation systems making programming much more convenient. Pentair has even developed an interface, called their IntelliComm, which allows the pump to be controlled by other manufacturer’s automation systems.
Finally, I should point out that Pentair has several versions on this pump. The least sophisticated is their IntelliFlo-VS-3050, which offers only four programmable speed settings with no built in timer. Another version, the one featured here, is their IntelliFlo-SVRS, which not only offers the energy savings but also the added benefit of a built in Safety Vacuum Release System, which is in compliance with the Virginia Graeme Baker Pool Safety Act, designed to protect swimmers from suction entrapment.
It has long been known we are effected by color. Our moods and emotions are altered by the application of the colors that surround us. For example artist, across a variety of media, have been using color to bring emotion to their creations since the beginning of time. Decorators use a similar understanding of color, carefully applying their knowledge in the selections of colors for various aspects to our homes. It is with the same attention to the detail of color, that a pool or spa can be enhanced, by color.
Red Stop Sign
You need not be an artist or decorator to appreciate the influences color has in our lives. Think of our automated responses in our daily lives to the colors of red and green. These colors are part of our driving experience representing simple basic commands of movement. Red means stop and green means go. In signage, on and off the road, red represents danger such as fire and heat. It should not be thought that our responses to these colors are based on our experiences in driving and signage, but the other way around. These colors were chosen to represent these dangers because they were already part our automated responses to these colors. These danger colors, red and yellow, are part of the color spectrum we associate with warmth and heat, while other colors, such as green, are associated with coolness and relaxation.
Perhaps our reaction is fundamentally based on nature’s choice of color. The sun gives off a yellow to orange color, while fire is predominantly perceived as red or yellow. Ironically as fire becomes hotter it changes to blue, which we naturally associate with cool, but lets not confuse things. Blues and greens are easily associated with water as in the oceans and streams, while green is associated with forests and plants. Both are cool to the touch and invoke images of relaxation and comfort.
Deep color of the Blue/Green Diamond Brite Verde
An artist will divide the colors into two groups, colors that are warm; red, orange and yellow, and colors that are cool; green, blue and violet. There are of course many other colors, but they all are some combination of these six primary and secondary colors.
It is important to note there are other responses, beyond a since of temperature, to colors as well. The warm colors seem to advance, meaning that they appear larger or closer than they are in reality, while the cooler colors tend to recede, as if moving away from us. This is particularly helpful when creating palates of colors for decoration purposes. It tends to manifest itself in our choices of the predominate colors and our contrasting highlight colors.
Another important characteristic of color, in terms of water, is that the color of the water often determines the ability to reflect. The darker the water the more the reflection capability. This may not seem important at first, but consider the use of mirrors in the home. Decorators have advocated using them strategically for years as they tend to make the space larger with the reflected images, sometimes doubling the enjoyment of objects being reflected. The water in a pool or spa can also achieve this same type of response, where it reflects the landscape and objects beyond. In the day light, these reflections could be of vibrant colored foliage, or even sculpture placed in the yard. At nighttime the reflection of lights and other lighted objects can be even more dramatic.
Blue-Green of the Ocean
So when choosing colors for your backyard water-scape, be it a fountain, pool or spa, the color you choose is extremely important and should be considered with care. After all, this place is where you want to spend time, so color away!
To view a pool being transformed with an application of a colored surface, Click Here!
Click below to see the same pool having the finish applied:
Not all water features need be massive rock waterfalls that relinquish a torrent of water and sound. Some of the nicest water features are small in size but powerful in effect. These smaller water features can stand on their own or be part of a larger body of water, such as a pool or even pond.
Disappearing Fountain
By far, the simplest of these features are the self-contained “disappearing fountains”. These simple devices are made up of two parts, a hidden underground reservoir and visible object which is enhanced by the movement of water. The underground reservoirs are usually slightly bigger than the above ground portion and are usually covered by rock, gravel even broken glass, which act as a screen, letting the water fall off the object and into the reservoir, but blocking the leaves and debris which would otherwise clog the reservoir. The reservoir acts as a holding tank for the water which is circulated through the object and also contains the pump which moves the water up through the object. The object is often some type of jar, but need not be. Water moving over a small stone can sometimes be captivating to view. If a jar is chosen, take care to choose one that is “high” fired and not a simple clay pot. The low fired pots will absorb too much water and break down rather quickly. The high fired pots are almost of porcelain quality and will last much longer. They cost more, but are well worth it. Take note of the object’s shape. The fascinating part of the fountain is watching the water move across the surface of the object, creating brilliant reflections as it captures the light in many ways.
Jar Water Feature
These features are a fantastic addition to your garden or even at the entrance to your home. They are simple to build and even simpler to maintain. The biggest demand is to make sure sufficient water is in the reservoir. If desired, this requirement can even be reduced by the addition of an auto-fill mechanism. Usually the only other requirement is to drain them in the winter to prevent the pot from breaking or the pump from running dry.
Copper Spill Bowl
If you already have a pool or spa, another option is to add a simple feature. These features are easiest to add during a renovation, but can be added as a stand alone project. They don’t need a hidden reservoir or dedicated pump as they usually are tied into the pools circulation system. One must be careful to chose objects that will hold up well to the chemicals usually found in pools, however many such products are specifically made just for pools. Many of these simple features for pools are shaped like bowls and have a lip designed to allow the water to roll of the edge without rolling back on the underside of the pot or deck. These pots can be made of metal, concrete or stone. Some are pre-finished with a “patina” to appear aged. Others include secondary purposes and double as fire features and planters.
Stone Spill Bowl
In all of the features there are two primary purposes that must be kept in mind, the sight and sound. They should be chosen for their visual interest, the way the water moves and catches the light as well as the visual interest of the object itself. However, the sound is just as important if not more so. These simple features create a gentle, soothing sound, designed to relax those within the hearing range. Don’t expect a loud noise to mask traffic or other disturbing noises, because they won’t accomplish that. They will offer, however, a place to read, talk quietly or take that much needed nap!
Click on the link below to see and hear one of these simple features in action.
In a recent renovation project, we had the opportunity to completely change the appearance of a pool by both the choice of our material, and by the attention to detail in its application. Originally the pool was surrounded by red brick. There was red brick everywhere, as coping to the pool beam and as a face to the wall of the pool. While I like brick as well as the anyone, in this application, it was not only dated, but very over-powering. It also created maintenance issues as the brick absorbed water from the spa spill-over, which left white calcium deposits and algae. Finally, the installation was less than stellar, in that they created a “reveal” on the face of the riser next to steps which had no such reveal. The placement of the reveal, which is the shadow line created by materials cantilevered, overhanging other materials, is important. It is often used to “reveal” elevation changes, or simple for the architectural value it visually creates. In this case the builder’s choice resulted in leaving an ”unfinished” face of the brick exposed, making me wonder, what were they thinking?
Surface Preparation
Our choice of material was travertine, which is one of the best materials to use around pools. Not only does travertine typically have a high compression strength, but it is one of the few materials whose traction coefficient increases as it gets wet. This means you are less likely to slip on the travertine when you exit the pool dripping wet, then when you entered dry. Rather than install the travertine in the same way the brick was installed, we decided to install the coping on both the horizontal and vertical surface of the risers. The stone was cut on miters for a simple clean, continuous look of the beautiful stone.
New Coping without Reveal
The resulting finish eliminated the reveal, making the surface flush with the face of the seeded aggregate deck work. Now the deck and coping are consistent with no unfinished sides exposed. Most materials are finished with sides that intended to be exposed and sides that are “unfinished” meaning they are intended to be hidden because they will be masked by the bonding agent or where they but against joining materials. This was not true before in our original pool and was corrected in the new coping work.
New Reveal on Coping
The reveal is now on the pool side and is consistent with the rest of the pool coping. Travertine is a material that is usually cut and polished creating a smooth and clean appearance. Our installation emphasized that detail, played off it and the overall result was impressive!
It is amazing, if not mind boggling, that something as big and as heavy as a concrete deck can move. One would think that something of this sort, when constructed would stay put. However, decks can and do move. Sometimes just slightly, with only slightly noticeable effects, and other times by several inches or more, where they are at the least a visual annoyance and perhaps a hazard.
Wide Expansion Joints
The reasons decks move are varied. All the reasons are built on the understanding that the deck is not moving alone. If a deck moves, it is likely that the soil underneath the deck has moved as well. The soil, must be thought of not as a solid material, but as a slow moving fluid. We have all noticed soil can appear to grow over concrete that is both adjacent and slightly lower in elevation than the body of the soil. Generally the soil, which is loose combinations of particles in varied size, is bound and held together by only gravity and the root systems of it’s plant life. If the soil is located on a level plane, the movement will be generally downward, thus the soil, overtime will become more compacted. If the soil is on a slope, the soil will move with the force of gravity down the slope. To complicate things, much of the soil in north Texas is made up of expansive clay. The volume of this soil is constantly being changed as it takes on and gives off moisture. Basically the soil is going through constant cycles of growth and reduction. Some soil is considered unusable for structural purposes, without special engineering, as it will not support the weight of heavy objects. Normally the weight of objects is transmitted down and outward from its base, but some soil, those with a high plasticity index, acts like small ball bearings, and moves out from under the object causing it to shift and sink.
These factors can generally be overcome, if they are known in advance of the construction process. This is why I recommend that before any building be considered, particularly where it represents a substantial investment, that the soil be tested professionally to determine its makeup and weight bearing capacity. If the condition of the soil is known and problems exist, they usually can be remedied. Possible solutions include compacting loose soil, removing bad soil, and replacing with compactible soil, proper foundation/footing sizing and placement, and to reach down to stable soil, piers and pilings.
Deck Falling Away
Where the deck has fallen away from the pool, the cause is likely the supporting soil was not compacted correctly. The picture shows a deck on reasonable level soil that over time settled away from the pool. The edge furthest from the pool had the most freedom and fell by several inches. The edge along the pool was likely tied structurally to the pool. The result created a hinging effect where the deck now leans. Note that on the accompanying raised deck section the deck movement is such that the brick and tile fascia have broken loose and and are no longer level with the pool structure.
Wire Mesh Reinforcement
In a recent renovation project we found the deck was moving away from the pool, sometimes just horizontally. In some sections, the deck sections had separated from each other where one section was 2″ higher than the adjacent section. In this particular case there had been little or no attempt to tie the sections together structurally. In fact, the only reinforcement existing in the deck was a wire mesh, insufficient in this case.
Structural Cracks
In some cases, where the soil has moved, the deck is unable to move, it responds differently, by cracking. A structural deck crack is one that exist all the way through the concrete structure and indicates a complete break. This type of crack is a failure of the concrete to resist external forces to bend. In some cases there was insufficient or incorrectly laid steel reinforcement within the concrete to withstand normal, expected forces. Other times, however, the deck was engineered with the assumption the ground would be stable and sufficiently compacted . If this was not actually the case and the supporting ground settled beneath the concrete, then the concrete would then have to span across the gap created by the settled earth, a condition it was not designed to withstand.
Lastly, I should point out there is a movement of decks and other concrete work which is not related to the soil. It is expansion and contraction. In this case the deck is not so much moving, as in away from or towards something else, as much as it is getting ever so slightly larger when it warms and then smaller when it cools. This type of movement is anticipated by the integration of isolation joints or expansion joints in the concrete. These joints are actually separations in the concrete works, usually filled with a flexible material. The concrete sections should not be structurally tied together unless designed by an engineer. Keeping them from from moving apart will be accomplished by properly addressing any soil concerns. Failure to install these isolation joints at appropriate locations can often cause their own problems, such as cracking where two sections, both expanding moved against each other.
