Preventing Weepers in Concrete Pools: Causes, Solutions, and Tips

Noticing Damp Spots or White Stains on Your Pool Walls?

Are you worried that your pool might have hidden leaks? These signs could point to a serious issue called weepers—water leaks that penetrate through the concrete shell of a swimming pool.

Weepers are more than just a minor nuisance. They signal potential structural problems that, if left unaddressed, could lead to costly repairs and even long-term damage to your pool.

In this guide, we’ll explain:

• What weepers are and how to identify them.
• What causes weepers during pool construction.
• How to prevent them with proper shotcrete application.
• Practical solutions for addressing existing weepers.

What Are Weepers, and Why Are They a Concern?

Weepers are water leaks that seep through a swimming pool's concrete shell, appearing as damp spots on the walls or floors. These spots may also create white mineral deposits, a phenomenon called efflorescence.

Unlike surface-level issues like condensation or minor cracks, weepers indicate water infiltration through the entire thickness of the concrete. This can compromise the structural integrity of your pool.

Signs Your Pool May Have Weepers:

• Persistent damp spots on the walls or floor of your pool.
• White, chalky deposits are caused by water moving through the concrete.
• Visible rust stains from corroded steel reinforcements within the concrete.

Why Are Weepers Dangerous?

Over time, untreated weepers can lead to:

1. Weakened concrete increases the risk of cracks.
2. Corrosion of steel reinforcements can affect the overall durability of your pool.
3. Expensive repairs, as more significant damage develops.

Why Do Weepers Happen?

Weepers are most commonly caused by errors during the shotcrete or gunite application process. Shotcrete is a high-velocity sprayed concrete that requires precision and expertise to apply correctly.

Here are the main reasons why weepers occur:

1. Improper Mixing and Placement

• If the shotcrete mixture is too dry or too wet, it weakens the pool shell and creates pathways for water to infiltrate.

2. Inadequate Compaction

• When concrete is not compacted correctly, voids or air pockets form, making it porous and prone to leaks over time.

3. Poor Application Technique

• Inexperienced or poorly trained nozzlemen may spray shotcrete unevenly, fail to maintain the correct angle or distance or overlook areas that need more attention.
• This results in thin or porous sections of concrete that are highly susceptible to water penetration.

Weepers vs. Efflorescence: What’s the Difference?

It’s important to distinguish between weepers and efflorescence, as they stem from different causes and require different solutions.

Key takeaway: If you see damp spots and suspect water penetration, your pool may have weepers, a structural concern that requires immediate attention.

How to Prevent Weepers in Pool Construction

Preventing weepers starts with high-quality craftsmanship and certified professionals. Follow these steps to ensure your pool is built to last:

1. Hire ASA-Certified Nozzlemen

Certified nozzlemen are trained to:

• Mix shotcrete to the proper consistency.
• Apply it evenly to ensure a dense, watertight structure.
• Identify and address weak spots during application.

2. Use High-Quality Materials

Source shotcrete mixes that meet or exceed industry standards for strength and durability. Work with reputable suppliers to avoid low-grade materials.

3. Monitor Construction Closely

Ensure experienced professionals supervise the shotcrete application. Look for:

• Consistent mixing and placement.
• Proper compaction without voids or air pockets.

4. Conduct Post-Construction Inspections

After completing the pool shell, perform thorough inspections to identify weak spots or leaks. This includes:

• Compression tests.
• Deputy reports obtained by building officials to ensure the pool meets safety standards.

How to Fix Weepers in Existing Pools

If your pool already has weepers, professional intervention is necessary. Here are standard repair methods:

1. Crack Injections:
   Use epoxy or polyurethane injections to seal cracks and stop leaks.

2. Waterproof Coatings:
   Apply specialized waterproof coatings to the pool's interior to prevent further seepage.

3. Reapplying Shotcrete:
   For severe cases, pool sections may need to be re-sprayed with shotcrete to restore structural integrity.

FAQ: Common Questions About Weepers

1. What’s the biggest cause of weepers?

The primary cause is poor workmanship during shotcrete application, such as improper mixing, compaction, or uneven spraying.

2. Can weepers be repaired, or do I need a new pool shell?

Weepers can often be repaired with crack injections or waterproof coatings. However, severe cases may require reapplying shotcrete to certain areas.

3. How can I find a certified nozzleman?

Look for contractors certified by the American Shotcrete Association (ASA). Always ask for credentials and verify their experience.

4. Does weather affect shotcrete application?

Yes, extreme weather conditions (e.g., rain, wind, high heat) can interfere with the curing process and weaken the concrete.

Why Certification Matters

Certified nozzlemen undergo rigorous training to ensure:

• Proper shotcrete mix designs.
• Consistent, high-quality application.
• Dense, watertight pool shells.

Hiring uncertified professionals increases the risk of construction defects, including weepers.

The Role of Training and Certification

Preventing weepers begins with proper training and certification of shotcrete nozzlemen. The American Shotcrete Association (ASA) and other industry organizations provide certification programs that ensure nozzlemen grasp best practices for applying shotcrete in various conditions. On January 1, 2023, the City of Los Angeles issued an information bulletin detailing the requirements for Wet-Mix Shotcrete application.  

Unfortunately, not all contractors prioritize hiring certified professionals. To cut costs, some companies employ untrained workers who lack the expertise to apply shotcrete correctly. This practice can lead to poorly constructed pool shells, raising the likelihood of weepers and other structural issues.

Building Pools That Last

Weepers clearly indicate compromised concrete integrity and addressing the root cause requires skilled craftsmanship, quality materials, and certified professionals.

Want to avoid costly repairs? 

Contact us today to build a pool designed to last. Our team of experts specializes in creating watertight, durable pool shells using certified nozzlemen and industry-best practices.

Weepers are more than just an annoyance—they indicate compromised concrete integrity. Addressing the root cause of weepers necessitates focusing on craftsmanship and using certified professionals during the shotcrete application process. By prioritizing proper training, quality materials, and diligent oversight, pool builders can significantly reduce the risk of weepers and create long-lasting, watertight structures that stand the test of time. 

If you're considering addressing or repairing the issue, consult an engineer. Various methods are available, but some weepers may not have a noninvasive solution.