Archive for the ‘Construction’ Category

City Permits & Utilities

Monday, March 16th, 2009
Dallas City Swimming Pool Permit

Dallas City Swimming Pool Permit

By Tim Long

After your pool has been designed, but before any construction begins, permits from the local authorities must be obtained. In most locations there will be some governing authority which oversees residential construction. The purpose of these authorities is to require that your plan will be up to the standards of the community. These requirements are in theory supposed to eliminate substandard construction practices and insure community safety and property values. However in practical terms its is most important to confident that your builder exceeds these minimum standards. The authority will require inspections at certain crucial stages of construction; typical after the steel reinforcement and electrical bonding and initial plumbing have been completed, but before the concrete has been applied; after the electrical and plumbing work was been performed and after the safety items have been installed, such as barrier fencing, but before the interior finish has been applied. Other inspections may be required depending upon the items being constructed.

You should know that these requirements are constantly changing. As an example, at this time, March 2009, we are seeing Federal requirements governing safety in pools, specifically the Virginia Graham Baker Act, being implemented. This law was designed, among other things, to reduce the possibility of suction entrapment on pool drain covers. Since the law is Federal it will take time until the local authorities codify such laws into community requirements. It is important that the designer and builder be well informed of all the requirements to insure that the most current thinking has been used in the construction of your pool.

Typical Plat

Typical Plat

When applying for a building permit for you pool, a fee will be required along with copies of the building plans. These plans will be reviewed to determine that the plans conform to the authoritie’s requirements. Your designer or builder should be aware of any requirements in your area, but as required, be flexible enough to adapt the plans to the requirements. Many of these requirements can be seen on your “plat” or scale drawing which visually describes your property. The plat, which you should have obtained when you purchased your home, should show the required “set backs” or “utility easements”. These are areas on your property on which you can locate substantial structures. “Variances” or exceptions can sometimes be obtained in certain circumstances to build in these areas, but many times these easements protect access to utility services which run throughout the community.

Excavation of a Pool

Excavation of a Pool

After the plans have obtained approval one further step needs to be completed before construction begins. In many areas the utilities, such as sewer, electrical, telephone and others, are buried in your yard. If excavation begins on your property and these utilities are damaged, it is possible that the homeowner will be held responsible for the cost of the necessary. These utilities must be identified before excavation. In many areas the utility companies, in an attempt to reduce or eliminate these accidental damages have set up organizations for the purpose of identifying these underground services. In Texas, for instance, there is a non-profit organization known as “TESS”, Texas Excavation Safety System. The builder should simple call TESS at least two days prior to excavation. A TESS member company will mark the necessary underground lines to help prevent any utility damage.

Gas Line Re-routing

Gas Line Re-routing

If it is discovered that utilities lie in or near the placement of the pool or other new amenities, the utilities may need to be moved. The cost of such possible movement has to be accounted for when planning your new pool. However such cost are usually nominal when compared to the cost of the overall project.

Read the previous article in the series, “It Begins With Design”.

Read the next article in the series, “Excavation - The Big Dig!”.

It Begins With Design!

Thursday, March 12th, 2009

By Tim Long

Pool with Spa

Pool with Spa

If you are interested in building a pool, spa or water-feature one of your first consideration should be its design, what size, shape, how it will look and feel in your backyard. This involves understanding the many factors such as thefeatures you wish to include and where you want them located. It also includes knowing how much you want to spend.

This process typically starts with a designer. Most people are not accustomed to design work and need assistance in this area. Fortunately, most pool companies provide this service as part of their company’s building program. Unfortunatly,  for many companies, the designer is nothing more than a salesman, who is more interested in telling you what type of pool he can build and what you need in your yard.

A good designer, by contrast, will listen and incorporate your desires into the process. He or she will start by exploring the area to be used and by asking you many questions. Of foremost interest is how you intend to use the space. If a “designer” presents you with a design having never asked this very important question, run! If he is not interested in how you intend to use the area, he can’t tell you what you truly need. Most people have at least general ideas about the pool they want, having seen pools at their friends, relatives or even at favorite resort. These ideas may include many specific features that they have seen and appreciated in their travels. However, as trends appear and new innovations develop, their may be many wonderful possibilities, ideas that you might eagerly embrace, if the designer suggest them having first asked that one simple question.

I mentioned that a designer must listen. But I mean to suggest something more that just passive hearing. The designer must understand your wishes, respect them and incorporate them into the plans. You can’t imagine the number of times I have heard clients indicate that the designer heard their desires, and then returned with pool plans that bore no resemblance to their ideas.  That does not mean a designer will always incorporate everything into the plan. Sometimes that is not possible or even prudent. A good designer should make recommendations that sometimes may be inconsistent with the client’s wishes. This is particularly important if the client’s desires have some hidden conflict which may not immediately recognizable. At times the client’s desires will conflict with the designer personal tastes. However, a good designer knows the difference between what is a potential design conflict and simply a matter of taste. 

Further, the designer should not only be aware of current needs, but inquire as to future considerations. Knowing about intended family additions, for instance, may allow the designer to suggest additional safety devices, perhaps not needed now, but plans could be made to allow the future implementation easier. Another example is where a total plan would include not just a pool, but an outdoor kitchen as well. Though budget constraints require these projects to be spread over time, it is important to keep future planning in mind. Some future project may be less expensive if they were combined, at least in part, early in the project. For example, in the case of the desired future kitchen, it may be prudent to lay the gas line, before the pool deck is placed, even though it may not be used immediately. That would far less expensive than having to break the deck to install the gas line later.

Light On Water

Light On Water

There is a danger here that you might become side tracked. It is easy to become so focused on specific ideas and plans that you forget to consider the complete picture of your yard. A thorough design is one that looks at the entire backyard experience. You may think you are just buying a pool so the kids can play after school. But you are in reality creating an experience that is not just to be physically enjoyed, but to be absorbed both visually and emotionally. The designer should help you think in these broader terms, seeing how your pool relates to these various considerations and view your pool as it relates to the entire yard.

However a good designer, also concerned with the details, will discuss the colors and textures of the materials found on or in your pool. Each of these things will have great bearing on the experience. Some colors are warm and inviting while others are colder and more ahloff. Some materials are smooth to the touch while others are rougher, each giving a different and distinct experience.

The differing materials which will make up your pool will meet, creating joints at various sections, such as where the tile and coping meet or where the coping and deck meet. Each of these meetings or joints must be “detailed”. Details should be planned so that where the materials meet it has the proper look. These things do not happen by accident. It is in paying attention to the details that will make a simple project extrodinary or conversely make an expensive project look sloppy. Inquire of your designer about such details. If he is good, he will know or at least discuss the possibilities. You may not be a designer, but on this point, trust your instincts. The best designs are usually collaborations between a good designer and an involved client. If you don’t work well with a designer, get a new one.

The Sound of Falling Water

The Relaxing Sound of Falling Water

Sound will also be a design consideration. I have seen many waterfalls placed on pools. They were probably created at the client request. However, because the design or lack of it, the noise from the waterfall was so intense it interfered with conversation around the pool. Instead of being a relaxing sound, it was a noise that had to be eliminated. There are many waterfalls that have rarely been used after just a few months or even weeks because of the sound issue alone. Talk to your designer. The sound of water moving is very relaxing, and visually captivating, but must be planned properly. Consider this. Water is its most quiet when it is at rest, meaning at balance with gravity. At the other end of the spectrum, where water is far from rest, it makes a violent crashing sound particularly when it falls from great height or with great volume. The most relaxing sounds come from water which is almost at rest. Since the sound is always a combination of height and volume, it seems prudent that they should be considered in the design, before construction. The height is difficult to change once the pool has been completed, water volume should be adjustable with proper valving.

Don’t forget lighting, in your pool and in your yard. Paying attention to lighting can greatly enhance and extend the hours you spend outdoors. Lighting should be considered carefully. Consider getting assistance from a lighting specialist. However the designer can help you determine what elements in your yard should be illuminated for both beauty and function. When it comes to pool lights in particular, I must address one of my pet peeves. For many years the lights have been station directly below the diving board, which in many cases pointed the light directly at the house. Even now, with many, if not most, pools being built without diving boards, the lights are still positioned so that the light source is evident from inside the house. It is the goal of good lighting technique to eliminate where possible the views of the light source from the main viewing locations, which means the lights of the pool, should be point away from, and not toward the house.

One other issue should be addressed in the design phase. It is my recommendation that a soil’s analysis be performed to determine the suitability of the soil where the pool is to be located. This testing may have been performed by the builder of your home. If so, it is likely that this earlier soil’s report will sufficiently reveal the soil condition where your pool is to be located as well. There are many pool builders who do not suggest this kind of testing. However it is important. Consider that the pool, when complete is likely to hold thousand’s of gallons of water, which weighs a considerable amount. You could calculate almost 8 pounds for each gallon, not including the weight of the structure itself. In many areas of the country the soil, in it’s natural, undisturbed state, can bare the weight of this pool. However, in other areas this is not the case. Even in good areas, if the ground has been previously disturbed, and fill dirt has been used to landscape, for example, the strength bearing capacity of the soil many have been weakened. In these conditions, and in conditions where the soil does not naturally have the sufficient bearing capacity, extra measures must be performed, to ensure the integrity of the new structure. In some cases, the engineers will order piers to reach down to good solid soil below. In other cases, over excavation is required to remove “bad” soil, then good soil is brought on site and compacted into place. Whatever measures are required, it is the soil test that will allow the proper steps to be taken. It may cost more to have the test completed, and if necessary, the extra steps that are a result of the test will certainly cost more. Yet the cost of repairing a pool that is no longer level far outweigh any initial costs! A good designer and builder will confirm this information and highly recommend this course of action.

In summary, find a good designer, one that asks many good questions, incorporates your ideas, pays attention to all the details including, but not limited to color, textures, materials choices, sounds, lights even soil conditions. Be ready to ask many questions of the designer, be involved, help him make the choices that best suit all your needs. Enjoy the process. But most importantly remember that he is not just designing your pool, he is designing an experience!

Read the next article in the series “City Permits & Utilities“.

Shot-Crete, Gunite what’s the Difference?

Monday, March 9th, 2009

By Tim Long

There is a lot of confusion over the difference between Shot-Crete and Gunite and which process should be used for your swimming pool or spa. Many pool builders will argue why the process they use is better than their competitor’s without really understanding the differences themselves.

If you were to research the American Concrete Institute or the American Shotcrete Association, you would find that both terms refer to the application process of good old fashion concrete. The concrete mixture travels from an applicator’s truck to the site via a large hose. Air pressure is applied and the mixture is “shot” into place at speeds approaching 200 mph. This is extremely important! Why? Because it is with the forced placement of the concrete that either process gains it’s merit. Any concrete placement should be “compacted” to remove voids, air bubbles that weaken the strength of the eventually hardened concrete. For concrete that is poured, applicators will use a variety of methods, tamping, vibration, etc, to achieve compaction, but no process by hand can compare to the compaction that can be achieved by the pneumatically applied shot-crete or gunite.

Why the two different terms? Shot-crete was invented by Carl Akeley, who received a patent on the precess in 1911. Originally the concrete mixture, which is made up of cement, aggregate was pumped through the hose dry. At the nozzle water was added along with the air needed to project the mixture. Today this process is now known as “dry-mix”. In the 1950’s it became possible to mix the water first, then pump the “wet mix”, only adding air at the nozzle. This was important for two reasons. The amount of water could be controlled more closely and the aggregate size could be larger than just sand, i.e. pea-gravel. (Note: the amount of water in concrete is the single most important factor in determining the strength of concrete). Today shot-crete has become a generic term which refers to both processes. However some in the pool industry use the terms shot-crete to refer to “wet-mix” and gunite to refer to “dry-mix”.

Which is better? That’s a hard question to answer, because it depends upon several variables. In theory, dry-mix should be stronger. The key is adding only enough water for proper “hydration”, the process which causes the cement to bond to the surrounding aggregate, and not a bit more. If the nozzleman is “certified” by the American Shotcrete Association, he has been thoroughly trained and tested on how to properly control the amount of water being added in the dry-mix. However, if the nozzleman is less skilled, he may add either too much or too little water, either extreme greatly weakens the future concrete. In the “wet-mix”, the moisture content can be more closely controlled, eliminating this as a variable. It is true that the moisture content is greater than can be achieved with properly applied dry-mix, but the possibilities of too little or too much water, have been eliminated.

There is also the question of “rebound”. Rebound refers to the aggregate, which bounces or deflects off of the receiving material and lands in areas other than intended. When the small piece of sand is in mixture, it is combined with the moisten cement and if properly placed will added strength to the structure. If on the other hand, bounces off something hard, such as the wooden form or a piece of the steel reinforcement, the cement is likely to adhere to the hardened surface, but the sand, now mostly stripped of the binding agent falls elsewhere. This rebound, must be gathered up and removed, not allowed to become part of the structure. To do so would be to create a weakened structure. It is known that the dry-mix process creates substantially more rebound than the dry-mix process. If the applicators are skilled in the process this deficiency can be overcome.

In summary, gunite or the dry-mix should be stronger, but the margin for error is too great in my opinion. Having seen too many failed dry-mix applications in my years of experience, I much prefer to use a shot-crete or wet-mix process in the construction of my pools and spas.

Here are some pictues of the shotcrete process and a short video of shotcrete being applied.