When it comes to building a swimming pool, what happens below the surface is just as important as what’s visible above it. In areas with unstable, expansive, or soft soils—or on sloped lots—standard foundations simply won’t cut it. That’s where deepened foundation systems come into play. These structural supports, often hidden underground, are crucial for ensuring the long-term stability and safety of a pool. Depending on site conditions and engineering requirements, contractors may rely on a variety of pier types—each with its own strengths and limitations. In this article, we explore the most common deep foundation options used in pool construction: friction caissons, driven piles, helical piers, and end-bearing caissons.

Deepened Foundations in Pool Construction: Caissons, Piles, and Piers Explained

Friction Piers/Caissons

Friction caissons are drilled holes, filled with reinforcing steel and concrete. The engineer calculates the friction between the earth and the outer surface of the concrete. These rely upon the surface area of the outside of the caissons and the coefficient of friction of the soil for support. Therefore, their diameter and depth are designed to develop sufficient surface area and soil friction. If the earth is removed they lose their ability to support the structure.

Driven Piles

Driven piles work in much the same way as friction caissons, except that they are pounded into the ground. Precast concrete, wood or steel I-beam piles are driven into the ground by a pile driver to the point of refusal. They are not often used in residential construction, due to the noise and ground vibration they cause.

The vibrations can actually damage nearby structures. They also require large machinery that often cannot access residential lots. Driven piles can be “end bearing,” friction or a combination of both. They are most often used in swimming pools adjacent to water (lake front, beach front, swamp land), that have soft or incompetent soils.

Helical Piers

Helical Piers are giant soil “screws” that are drilled into the soil. They have significant limitations, due to their size and method of installation. Helical piers are limited in their load bearing capacity to the torque that the installation machinery can deliver. Helical piers also do not perform well in loose or soft soils. Their development depth is limited by the length of the shaft.

For pools, helical piers are most often used in areas of expansive soils or high water tables to hold down the structure. They are the most economical and weakest of the available options. To resist point loading on the tip of the shaft, grade beams or mat foundations are often utilized to spread the load across the underside of the pool floor.

End-bearing caissons

As the name implies, end-bearing caissons (seen above – Featured Image) are drilled or driven until the end of the pile contacts supporting bedrock or soils. They often develop support through a combination of skin friction and end load bearing. Bell caissons, flare out on the bottom to increase the contact footprint of the shaft. They require specialized augers to create the flared end.

The portion of a pier above grade is a “free standing” pier (aka: column). The tops of the columns are tied together by beams or a mat foundation to resist movement. They are often seen on bridges, overpasses and above grade swimming pools.

You can see why a soils report is required for pier supported structures. Without a soils report, the structural engineer will not know the soil’s coefficient of friction, it’s load bearing capacity or the expansion index for their design.

Conclusion

When it comes to pool construction, building a structurally sound pool on challenging terrain requires more than just a good understanding of design—it demands a deep understanding of soil behavior and the right foundation system to match. Whether it’s friction caissons, driven piles, helical piers, or end-bearing caissons, each solution serves a specific purpose based on site conditions and load requirements. Because these systems involve critical calculations and specialized installation methods, they’re never a DIY task. A thorough soils report and the expertise of a qualified structural engineer are essential. For pool contractors working in uncertain ground conditions, relying on professional guidance isn’t just smart—it’s a matter of long-term safety and liability.

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When it comes to swimming pools, a “Lifetime Warranty” is only as good as the company behind it. Let’s face it, most warranties are part of a pool company’s marketing program, used to entice consumers with a guarantee as to the quality of their prospective purchase. Before a purchase, the warranty says “our product is SO GOOD, we guarantee it for life”, but how good is that pool warranty, really?

Warranties usually are not financially backed by an insurance policy or surety bond. Warranties are supported by the good will and financial solvency of the business that provides them.

Many consumers are confused by this. Some expect general liability insurance companies to provide a blanket lifetime warranty, if the company goes out of business. This often leads to consumer disappointment.

The Difference Between a Warranty & Insurance

There is a significant difference between warranties and insurance coverage. One is a self-funded program by the company, while the other is backed by the investments of an insurance company.

Warranty coverages end when the company ceases operations. Insurance coverages typically extend beyond the company’s operations.

Only companies that purchase insurance coverage or partner with a third-party warranty company to cover their warranty liabilities, will have warranty coverage after they cease operations. Such policies and services are expensive and rarely used throughout the pool industry.

Ways Pool Professionals Can Improve Warranty Coverage

To offer better warranties to their customers, pool professionals should enhance transparency and communication. Providing clear, detailed documentation outlining what the warranty covers, including any exclusions or limitations, is crucial. Educating customers about the terms of the warranty and the distinction between warranties and insurance through informational sessions or brochures can further clarify these aspects.

Supporting Customers After The Sale

Implementing a robust after-sales support system is another essential step. Establishing a responsive customer service team dedicated to handling warranty claims and inquiries ensures timely and effective resolution of any issues. Offering maintenance services helps customers keep their pools in optimal condition, preventing issues and reducing warranty claims. Providing comprehensive warranty coverage that includes a broad range of potential issues, such as structural defects, equipment malfunctions, and surface problems, can further enhance customer confidence. Allowing warranties to be transferable if the property is sold adds value to the customer’s investment and facilitates the sale of their home.

Plan For The Long Term

Partnering with reputable third-party warranty companies can provide financial backing, reassuring customers that their warranty will remain valid even if the pool company ceases operations. This partnership can also offer extended warranty options, allowing customers to choose additional protection based on their needs and budget.

Finally, monitoring and improving financial stability through regular audits and considering insurance policies that cover warranty liabilities provide additional layers of security for customers. Fostering customer relationships through regular check-ins and implementing feedback mechanisms helps build long-term relationships and ensures customer satisfaction. By implementing these strategies, pool professionals can offer better, more reliable warranties to their customers, enhancing trust and satisfaction while strengthening their reputation and credibility.

Important Questions To Ask About Your Warranty

This article is equal parts education for pool professionals and consumers. Below are just a few of the most important questions that consumers need to ask their pool professional when it comes to their swimming pool warranty.

Research the Company’s Stability:

Example Question: “How long has your company been in business, and can you provide references or testimonials from past clients?”

Understand the Warranty Terms:

Example Question: “What exactly does the lifetime warranty cover? Are there any exclusions or limitations?”

Clarify the Financial Backing:

Example Question: “Is the warranty backed by an insurance policy or a surety bond?”

Example Question: “What happens to the warranty if your company goes out of business?”

Differentiate Between Warranty and Insurance:

Question: “Can you explain the difference between your warranty and what is covered under any insurance coverage you might offer?”

Question: “Are there any third-party warranty companies you partner with to ensure coverage if your company ceases operations?”

Inquire About After-Sales Support:

Question: “What kind of support and service do you provide after the sale and installation of the pool?”

Question: “How quickly can I expect service if there is an issue covered by the warranty?”

Review Documentation:

Question: “Can I have a copy of the warranty terms and conditions to review before making a purchase?”

Question: “Are there any steps I need to take to ensure the warranty remains valid?”

Ask About Maintenance Requirements:

Question: “Are there specific maintenance requirements I need to follow to keep the warranty valid?”

Question: “Can you provide a recommended maintenance schedule and any services you offer to help maintain the pool?”

Navigating the intricacies of pool warranties can be daunting for consumers, but with thorough research and the right questions, it’s possible to make a confident and informed decision. By fostering clear communication and providing reliable information, both consumers and pool professionals can create a positive experience that extends far beyond the initial purchase. Remember, a warranty is only as good as the company behind it.

Designers and builders need to be intimately familiar with the building codes as they relate to swimming pool construction. This is particularly true when creating concepts that could be potentially hazardous pool designs. Most state building and residential codes have adopted the ISPSC as “the code” for swimming pools for good reason.

Following ISPSC Can Help Prevent Hazardous Pool Designs

The ISPSC is broken down into sections. One that applies to all pools (Section 3), another to in-ground residential pools, another to commercial pools, etc. Since the introduction of the 2012 ISPSC, Section 323.3 has prohibited any obstruction that can cause entrapment or injury. It goes on to provide a few examples (not inclusive of all possible hazards) such as: wedge or pinch type openings and non-giving cantilevered protrusions.

What qualifies as a wedge or pinch type opening? Any gap where a bather may become wedged or pinched. These hazards are compounded when they are underwater, where they may trap a swimmer and result in a drowning. These openings may be from cantilevered steps, boulders, even a stainless steel ladder that hangs into a pool. To say it won’t happen, unfortunately, is wishful thinking. Swimmers have actually drowned by becoming caught between an SS pool ladder and the wall.

What is an example non-giving cantilevered protrusion? Think of a stone or concrete table on a concrete pedestal, surrounded by benches. A swimmer under the table, could easily panic and become trapped between the tabletop and bench. An underwater tunnel or rock work that hangs significantly over the water are other examples.

These details may seem cool in concept, they pose real and significant hazards to inexperienced swimmers who easily panic when they choke on water, run out of air, or resurface directly under an obstruction.

While state or local jurisdictions are only allowed to make the codes more stringent, they are not allowed to waive a code or standard that specifically prohibits a hazardous condition.

Why Follow ISPSC Guidelines?

The International Swimming Pool and Spa Code (ISPSC) is considered the gold standard in the pool industry due to its comprehensive, detailed, and safety-oriented approach to pool and spa construction and maintenance.

When embarking on a pool project, it is crucial to consider the International Swimming Pool and Spa Code (ISPSC) standards not only during the construction phase but also from the very beginning of the design process. Here’s why integrating ISPSC standards at the design stage is essential:

1. Ensuring Feasibility and Safety: Integrating ISPSC standards early ensures that design concepts are both feasible and safe, preventing the creation of unsafe or impractical features.
2. Streamlining the Approval Process: Adhering to ISPSC guidelines from the start simplifies regulatory approvals, reducing the need for revisions and accelerating project timelines.
3. Avoiding Costly Revisions: Early compliance with ISPSC standards prevents expensive and complex modifications during or after construction, ensuring a smooth and cost-efficient project.
4. Enhancing Functionality and User Experience: Designing with ISPSC standards ensures optimal water quality, efficient maintenance, and accessibility, leading to a better and more inclusive swimming experience.
5. Future-Proofing the Design: Compliance with ISPSC standards helps future-proof the design, ensuring it remains relevant and safe as regulations evolve.

The ISPSC is developed by the International Code Council (ICC), a renowned authority in building safety and fire prevention. The code encompasses all aspects of pool and spa construction, including design, installation, operation, and maintenance. Its guidelines are meticulously crafted to address potential hazards, ensuring that pools and spas are safe for use. This thoroughness helps prevent accidents and injuries, making it a trusted standard among professionals.

A Uniform Set of Standards

The ISPSC provides a unified set of standards that can be applied nationwide and internationally. This uniformity is especially important for pool builders, designers, and inspectors, as it ensures that safety and quality are consistently maintained across different regions. This consistency helps to eliminate confusion and discrepancies that can arise from varying local codes, making the ISPSC a reliable and predictable framework for the industry.

The ISPSC covers a wide range of pool and spa types, including residential and public pools, spas, hot tubs, and aquatic recreation facilities. This broad scope ensures that the code addresses the unique safety and operational requirements of different types of installations. Whether dealing with a small backyard pool or a large public aquatic center, the ISPSC provides applicable guidelines to ensure safety and compliance while preventing potentially hazardous pool designs.

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