A two part article authored by Chuck Grosse.
Part II: Construction Defects
In part one I outlined a variety of hazardous conditions I commonly find in pools I visit while vacationing in Mexico. While these observations do not mean that every pool in Mexico has these conditions it does indicate that the conditions are not being spotted during construction or during maintenance at the locations where I have seen them. Along with the physical hazards I also see quite a few “construction defects” some of which are more aesthetic in nature, but quite a few are the kind that mean the pool may not survive well. First I will mention some of the lesser of the evils, the aesthetic defect.
Cosmetic fit and finish is first in line. Stonework, tile work, and concrete deckwork seem to have their own standard in Mexico. A defect that would result in work being removed and replaced in the U.S. seem to pass inspection. Things like the quality of materials used, the size of grout joints between stone or tiles, how those joints are cleaned and finished, and material residue left on the finished product are the most obvious.
Many coping and deck materials seem to be fabricated “on-site” in the form of poured in place or pre-cast segment, and the materials used and finishes rendered are commonly inferior. Poor cement mixes lead to quick deterioration in the pool environment, so many pool copings and decks look old and tired almost immediately. In this case the investment quality materials would be a huge benefit to the end user, since the labor cost for installation, where huge savings can be found in Mexico, would remain basically unchanged. The pool designer should be specific in the materials of choice and the builder should follow the specs.
The all tile pool is extremely popular in Mexico, in part due to the fact that man-power is cheap, but also because the skilled crews needed to install plaster-type finishes are almost non-existent. Also a tile pool offers a nearly “lifetime” finish which can be repaired over and over again, if surplus tile is reserved for that purpose to avoid a mismatch. Fit and finish is the end-game of tile, and pools, because of their odd shapes and curved surface require particular attention to detail. Although grout is a necessary component of tile, the less grout used the better the job. By making accurate cuts and a tight with even gaps between the tiles a skilled worker leaves his mark.
At most every pool one can see “patch” repairs where off-colored tiles have been used to make some sort of repair on the interior of the pool. If only a bit of extra tile was ordered when the pool was built and properly stored for future repairs these patches would not exist. At Del Rancho Pools, where I work, we typically order a 10% waste factor since the tile is usually fairly inexpensive, then leave whatever surplus we have with the owner to store INDOORS so that the tile is usable at the time repairs become necessary.
At many projects irregular grout joints are everywhere, both in the pool and on the surrounding coping and masonry work. Pools projects tend to have a lot of grout involved in them, and several men, or sometimes several crews of men, will be needed to complete the installation in a reasonable length of time. The least skilled man or crew is what sets the projects’ standard, unless the supervisor demands better. It is the superintendent’s job to oversee the work and check for a uniform level of quality.
I also see a lot of poor workmanship in the way of grout clean-up at the time of installation. Grout is sloshed over the surface of the tiles and left to harden where it falls. You’d think that sponges and rags were in short supply. Here again the least skilled set the standard unless the foreman steps in.
The above mentioned cosmetic defects can all be stopped IF, and only, if the project foreman or superintendent sets the bar high enough for the finished product. Make sure your PM (project manager) understands your standard and communicates it down the line.
There are also defects that are not very visible but do affect the functionality of the pool or spa. Plumbing defects, pipe sizing, skimmer type and location, and equipment choices are the major players. Proper design and good project supervision will help end these plumbers pitfalls.
Spas built in Mexico tend to have the worst jets I have ever seen, with almost no force and no bubbles. If a spa is properly plumbed with all the pipes in the right places and has a pump sized for the number of jets installed there is no way to get weak jets with no bubbles. I seriously doubt that most of the Mexican pool plumbers have ever samples their own wares, understand how jets should work and feel, or been shown how a properly plumbed jet system show look. Pump sizing (to weak) and air (or lack of it) are the typical problems. Most spas will need a variable speed pump or a second spa jet pump to give good jet action. At most of the pools I’ve seen you’d be lucky to find one old, dilapidated, and undersized single speed pump. Along with a strong pump spa jets need air. Without it there is no vigorous massage action from the jets. The internal workings of the spa jets actually need the air and water to enter through separate ports to create a venturi effect in which the water “drags” additional air in, which in turn allows the water to travel faster out of the nozzle than it could by itself. This is what creates the “massage” action in the spa. Often it seems as thought the pipes get crossed underground with “air” pipes feeding water and “water” pipes pumping air. Once this happens the mis-routed water actually kills the venturi effect and the jet fails to draw in air. That causes the weak jets. There are also plumbing techniques unique to pool plumbers that actually help the venturi air reach the jet quicker and with less resistance. Although the spa plumbing is the responsibility of the plumber, it is also the job of an experienced supervisor to be able to look at the spa plumbing and intuitively know whether it will work properly before it is tested in the finished spa. If he is not certain it will work he should find out before the plumbing is encased in concrete.
In the U.S. pool builders have began to focus on properly sizing the plumbing of a pool to reduce water flow speeds within the pipes and thus improve energy efficiency. Hydrodynamics is a science in itself and a bit much to try to explain in this discussion, but let it suffice to say that in general a larger pipe is better than a smaller pipe, within limits. In the U.S. it used to be that 2-inch diameter pipe was considered large enough for nearly every application. Now that standard has moved up a notch or two and pipe sizes of 2.5-inches to 3-inches are the norm, with pipes of 4-inches and even 6-inches not un-common. In my travels I often see pipe sizes of 1.5-inches and sometimes even less at many of the pools. I have rarely seen pipes over 2.5-inches in diameter. Larger pipe sizes not only offer better energy efficiency but can also improve equipment lifespan, but are actually thicker walled and more durable in the ground. Here the pool designer must specify the size of pipes to be used for the various pool systems and the PM or builder must follow through to make sure the plumber does not make substitutions in the field based on his common-knowledge.
The function of a pool skimmer is a mystery to many in Mexico, and its form and placement is mostly an after-thought. Most pools and spa have at least one skimmer, and often more are needed depending upon the plumbing configuration and number of pump systems installed. In the U.S. multiple skimmers per pump are now the norm and they are typically place to help with pool circulation and to strategically capture floating debris in a variety of weather patterns. Most are commercially fabricated from plastic with hinged “weir” gates to keep debris inside once captured and removable baskets to keep debris out of the pump and allow for easy cleaning of the basket. In Mexico skimmer placement seems arbitrary at best with the skimmer often located as close to the pool equipment as possible. While this will reduce the amount of pipe used in construction it is usually not the best location to capture debris. Also many are “custom built” out of concrete with no weir gate or basket at all. This means that skimming action may not be happening, and that if debris that enters the skimmer it will ultimately fill the pump basket (or clog the pump), further reducing circulation. Remember that circulation is key to sanitation and without it sanitation is not possible. A properly designed plumbing system with the correct number of skimmers and their positions carefully noted is necessary. The builder needs to understand the importance of this system and install it per plan.
At its most basic a pool needs a pump and filter to stay clean. The pump moves that water through the filter and the filter removes particles from the water. In Mexico nearly every pool is just that, basic. The problem is that along with being basic the pump and filter are also small. Way too small. A pool filter needs to be sized for the pool it filters AND for the maintenance it receives. If a filter gets cleaned weekly it needs to be able to filter a weeks worth of particles. If a pool gets used a lot it needs a bigger filter and/or more maintenance. So many times I have seen a filter that would be considered too small for a residential pool in the U.S. installed on a commercial pool with quadruple the bather load in Mexico. That same filter is also of an older model and by just looking at it you can tell that it rarely if ever gets cleaned. Some of these filters are so old and in such condition that merely disassembling them for cleaning would be their end. At the same time some of these older and undersized filters are paired with an older and undersized pump. How a tired old pump could get water through a clogged up filter is a wonder to me, but I bet it doesn’t happen. Here again the designer needs to understand how much use a pool will get as well as how often maintenance will be done. The designer will then be able to determine what size filter is needed and pair that with the appropriate sized pump. Again don’t let the builder let his experience be his guide; it is your custom pool.
Of course custom pools almost always have more equipment than just a pump and filter. Booster pumps, heater, sanitation systems, solar systems, and pool controllers are all possible components in your project. Each of these components will mesh with the others to form a complex pool equipment set and should be tailored for your needs. Let your designer help you with these choices and make sure again that your builder follows the specifications without un-approved field substitutions.
So far I have talked about many kinds of construction defects, but the ones I will now mention are the real deal. We are talking things that will literally cause a pool to break. Things like engineering, soil, rock, concrete, and steel. If these items get screwed up the ones above will not even matter.
Many of the pools which are built in Mexico are designed by an architect with only the aesthetics in mind. It is left up to the builder to determine how to implement the design chosen from a structural standpoint. Building permits may be issued but often do not include the engineering and inspection aspects that we are used to in the U.S. The permit is more of a way for the local government to document and tax the construction than a method to assure quality. Inspections often occur only once a project is completed. Whether or not the engineering aspects of the project are addressed is not an issue for the authorities.
With that said I must note that is nearly opposite of the U.S. process. Pool permits in California are typically obtained by submitting pool plans and corresponding engineering designs together to the city building department for review. Once approved the construction process is inspected at key points for compliance with the approved plans and engineering. This process ensures that design and engineering work together for the benefit of the pool. In Mexico it is up to the buyer and ultimately the builder to ensure that the desired level of construction quality is upheld. The buyer often knows nothing about pools, so must then rely on the architect and builder to do what is best.
In Mexico they build pools just about anywhere. On flat land, a sloping hillside, or the side of a cliff overlooking the sea. Although each of these is a potential pool location, each site is unique. Each has it’s own engineering concerns and needs to be treated differently. If the sites are treated the same then some of the pools might fail (crack or break). My observation is that often the very same construction techniques and materials are used to build the pool on a cliff that are used to build a pool on flat land, and I have seen the consequences. From my room once in Puerto Vallarta my view was down towards the beach where a half-filled pool sat with a big wet stain on the exposed pool wall facing the bay. The pool had not been designed properly for the exposed wall and the wall had cracked. That pool needed to be removed and rebuilt if the owner wanted a pool. I was told the pool had been in that condition for several years.
In the U.S. it is up to a soils engineer to determine whether a site can support a pool and what loads the soils can handle. He can also determine if the site can be improved to support a larger load. Once the soils have been analyzed that information is given to the structural engineer, along with the pool design showing the location of the pool relative to the site. The structural engineer then determines how the concrete and rebar will be arranged to give the pool the strength it needs for its soils conditions. The builder must then follow the engineering plans during the construction process. We, as builders, rely on our structural engineers to let us know what sized bars go where and how thick the walls need to be for the desired strength and the site’s soils conditions.
My experience in observing construction using concrete and reinforcing steel (rebar) in Mexico is that the relationship between the two that provides strength to structure built from these materials is not well known by the tradesmen themselves. There is a required balance needed for the relatively brittle concrete and the flexible steel to unite into a strong yet forgiving structural media. It seems as though the “common practice” in Mexico is routinely accepted as sufficient regardless of the project or site conditions. Compared to U.S. standards most construction has too little concrete and not enough or under-sized rebar.
The only solution here is to demand that U.S. standards for soils engineering and structural engineering be followed in the construction of your pool. Your builder and supervisor must know how to read engineering plans and how to implement the various details included at the proper places in the project. If they cannot do this they cannot build you the pool as designed.
In conclusion I want to make it clear that not all pools built in Mexico are poorly designed or under-built, but that quite often the standards most pool builders in the U.S. are accustomed to are not followed. This may result in just a small inconvenience, but could also be much worse. If you intend to build a pool in Mexico and expect it to be built like a pool would be built in the U.S. you may be disappointed unless you find a designer and builder/supervisor who is experienced with the U.S, standards and is able to convey those to the workers and follow through during the construction process. If you have any questions please feel free to contact me via e-mail.
Chuck Grosse
Pool Designer and Project Manager
PoolManChuck@gmail.com
