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Concrete Crack Injection – Polyurethane

Concrete Crack Injection Polyurethane

Introduction:

Maintaining the structural integrity and aesthetic appeal of concrete constructions is crucial for ensuring their long-term durability and functionality. Water intrusion, often through leaking cracks, poses a persistent challenge that can lead to structural erosion, aesthetic damage, and costly repairs if not addressed effectively.

Leaking concrete cracks are a common issue across various types of infrastructure, from residential foundations to industrial facilities and public spaces. Repairing these cracks requires advanced techniques that not only stop water infiltration but also reinforce the structural resilience of the affected area.

Concrete Crack Injection using Polyurethane (PUR) Water Stop Foam Injection is a cutting-edge, economical solution that provides a permanent seal for leaking cracks. Renowned for its versatility and efficiency, this method effectively addresses a wide range of water damage issues, including structural weakening, rust stains, and efflorescence buildup.

In this article, we explore the PUR Water Stop Foam Injection process, highlighting its procedure, applications, and advantages. By adopting this innovative technique, engineers and contractors can maintain the integrity of concrete structures, safeguarding them from further damage while extending their service life against the forces of nature.

How to Seal Leaking Concrete Cracks with PUR Water Stop Foam Injection

Zoo Exhibit Crack Repair — The Gorilla Exhibit at Omaha’s Henry Doorley Zoo was closed for renovations and repairs, including the sealing of concrete cracks that had shown signs of water intrusion, structural erosion, and visible stains from rust and efflorescence.

Concrete crack injection with polyurethane foam resin was the choice of repair to resolve water bearing crack leaks. Crack related damages were located at a walkway under a lofted area with multiple windows and decorative shotcrete structures where gorillas could sit and be viewed by people walking through the exhibit.

The cracks were covered in efflorescence could be seen on the walls below the lofted area as well as cracks coming off the cold joints around the precast window framing.

The crack dimensions ranged from hairline to 1/4″ joint seams with varying degrees of water intrusion and active leaks causing heavy efflorescence build up. The roof and lofted area collect and feed water during snow melt and heavy rains.

SealBoss provided an on-site technical representative to consult with the contractor on injection methods using NSF/ANSI 61 Drinking Water Contact Certified injection grout, a high-pressure injection pump and mechanical injection packers.

Concrete Crack Injection – Polyurethane

Which products are shown in the video?

Concrete Crack Injection Polyurethane – Procedure and Repair Method

Prior to injection, the contractor had to first prep the cracks by removing any efflorescence and dirt build-up from the face of the crack using a wire brush.

Once the cracks were visible an injection plan was established to address the leaks working from the low point up.

Using the SealBoss high pressure concrete crack injection system — hydro-active, hydrophobic polyurethane foam resin, injection packers and polyurethane crack injection pump — hydro-active foam resin is injected into the cracks, expanding on contact with moisture and displacing any water in the process while creating an airtight & watertight seal.

Crack Injection Details

A – Standard Injection Procedure

One side of the lofted area had three significant cracks that resulted in substantial active leaks. The east wall presented larger actively leaking cracks. Further, cracks and cold joints from a precast window frame created an area of leakage that needed to be injected.

In those areas, SealBoss 1/2 inch injection packers were placed according to SealBoss Standard Recommendations, roughly 4” from the crack in ½” holes that were drilled at a 45-degree angle back into the crack. SealBoss 1510 Water Stop Foam was injected until positive refusal of the hydro-active resin was visible from the face of the crack as well as on the exterior side of the wall when a through crack was injected.

Starting with the lowest point of the cracks, SealBoss 1510 Leak Sealing Foam Grout was injected until positive refusal was observed on the interior and exterior of the wall. Due to the temperature of the wall, around 36 degrees Fahrenheit, the contractor was advised to condition the resin to room temperature prior to use as well as adding 15% of SealBoss 1510 Accelerator/Catalyst to compensate for the cooler ambient and substrate temperature — cold temperatures slow down the chemical reaction of the injection grout.

B – Custom Injection Procedure

In some areas, more complex leaking cracks and cold joints had to be sealed, requiring a deviation from standard injection packer placement.

Multiple cracks had developed connecting to a larger initial crack, creating a spider-web crack pattern. Due to the complexity of the crack system and intersections of cracks, the injection procedure was modified from the standard alternating “zipper” pattern typically recommended. Cracks were so close in proximity that packers needed to be strategically ‘custom’ placed to increase the chance for each packer drill hole to successfully intersect with the crack — resulting in a less orderly packer placement pattern.

Starting at the low point of crack, the Water Stop Foam was injected till and foam travel was observed at a distance from the point of injection intersecting into other cracks. This meant that multiple cracks could be addressed from one point of injection without the need for drilling too many injection port holes.

As the resin visibly moved up and out of the face of the crack, injection of that specific crack would be stopped so the resin could react and fully expand creating a seal.

Shortly thereafter, a secondary injection of the same packer was performed to penetrate even deeper into the crack and allow for further continuation of visible vertical foam resin travel.

Cleanup

After all cracks were successfully sealed, the injection packers were removed, and the ½-inch drill holes were patched with hydraulic cement for a clean finish. This step restored the surface integrity and appearance of the repaired areas.

Products Used:

Injection Resin:

Other Tools Used

Cleaning Materials: Xylene, rags, bucket
Additional Tools: 18” x 1/2″ drill bit — 3/8” Crescent Wrench — Dead Blow Hammer
Hammer Drill — Access 110v Power —
Vacuum
Heat Gun

Why Polyurethane Foam Injection?

Polyurethane foam injection is a versatile and effective solution for sealing leaking cracks in concrete structures.

Its advantages include:

Hydro-Active Expansion: Reacts with water to create a watertight seal.
Durability: Provides long-lasting protection against water intrusion.
Flexibility: Can adapt to various crack patterns and sizes.

This method proved to be the ideal choice for the Gorilla Exhibit, ensuring a safer and more enjoyable environment for both animals and visitors.

Conclusion

The repairs at Omaha’s Henry Doorley Zoo highlight the effectiveness of polyurethane foam injection for sealing leaking cracks, even in complex and challenging environments. With proper preparation, high-quality materials, and expert execution, this method offers a reliable solution for protecting concrete structures from water damage.

Call Your SealBoss ® Technician

If you have any questions on crack injection water stop procedures or any injection related applications, please contact our team of qualified SealBoss representatives to schedule an on site consultation & full injection systems training. Call us at 714-662-4445.

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Types of Concrete Cracks

A Concrete Crack Overview

Introduction:

Concrete structures can experience a range of cracks due to various causes, including environmental factors, structural issues, and material weaknesses. As a concrete repair professional, understanding these different crack types and how to address them using suitable repair methods—such as polyurethane resin, foam injection, acrylate gel, and epoxy injection—is essential for maintaining the integrity and longevity of concrete structures.

For Concrete Crack Repair Details read our Quick Guide

Concrete Crack Repair – A Quick Guide to Polymer Grout Injection

Types of Concrete Cracks

Shrinkage Cracks in Concrete
Shrinkage cracks occur when hardened concrete loses moisture during the curing process, causing it to contract. These cracks are common in driveways, slabs, and foundation walls. As concrete dries over time, this moisture loss can lead to shrinkage if the concrete is restrained, resulting in cracks. These cracks may be larger and can appear throughout the structure.
Cause: Uneven moisture loss and restraint in the structure.
Repair Solution: Polyurethane resin, foam injection, depending on the severity and circumstances, to seal the cracks, prevent moisture ingress, or, in some cases, epoxy injection to regain structural strength.
Plastic Shrinkage Cracks in Concrete
Plastic shrinkage cracks form while the concrete is still in its plastic (unhardened) state. They result from rapid moisture evaporation from the surface, often due to high temperatures, low humidity, or strong winds. These shallow cracks resemble a spiderweb pattern and typically affect newly poured slabs.
Unlike regular shrinkage cracks, which develop after the concrete has hardened and contracted over time, plastic shrinkage cracks appear within the first few hours after pouring, making them a common issue in newly poured slabs or exposed surfaces. These cracks are typically shallow and widespread across the surface, while regular shrinkage cracks are generally larger and occur throughout hardened concrete structures.
Cause: Rapid moisture loss from the surface during curing.
Repair Solution: Typically Polyurethane resin, foam injection, depending on the severity and circumstances, to seal the cracks, prevent moisture ingress. Acrylate gel in some cases.
Spalling Concrete Cracks
Spalling occurs when sections of concrete break away from the surface, exposing the reinforcing steel. This typically results from corrosion within the steel, causing it to expand and exert pressure on the surrounding concrete.
Cause: Corrosion of embedded reinforcing steel.
Repair Solution: Epoxy injection to fill and bond the cracks, combined with a surface coating to prevent future corrosion.
D-Cracking in Concrete
Durability cracking, or D-Cracking, results from concrete’s inability to withstand freeze-thaw conditions. It usually manifests as cracks running parallel to joints or linear cracks, often with discoloration around the affected area. D-Cracking is primarily caused by the use of coarse aggregates that trap moisture, which expands during freezing and leads to cracking over time.
Cause: Coarse aggregates that absorb moisture and expand during freezing.
Repair Solution: Polyurethane injection, which remains flexible during freeze-thaw cycles.
Corrosion Cracks in Concrete
Corrosion cracks develop due to the rusting of steel reinforcement embedded in concrete. As the steel corrodes, it expands, creating internal pressure that leads to cracking.
Cause: Rusting of embedded steel.
Repair Solution: Polyurethane resin, foam injection, depending on the severity and circumstances, to seal the cracks, prevent moisture ingress, or epoxy injection to regain structural strength.
Stress Corrosion Cracks in Concrete
Stress corrosion cracks arise from a combination of tensile stress and a corrosive environment. These cracks are common in marine structures, bridges exposed to de-icing salts, or industrial facilities where chemical exposure is prevalent. This phenomenon often involves the interaction of aggressive chemicals (like chlorides or sulfates) with embedded steel reinforcement, resulting in cracks that may propagate rapidly under continued stress.
Cause: Interaction of tensile stress with corrosive chemicals.
Repair Solution: Polyurethane resin, foam injection, depending on the severity and circumstances, to seal the cracks, prevent moisture ingress, or epoxy injection to regain structural strength.
Overloading Cracks in Concrete
Overloading cracks develop when concrete structures bear more weight than they were designed to handle. These cracks usually occur in heavily trafficked areas like driveways or industrial floors where heavy machinery operates.
Cause: Excessive loads exceeding the design capacity.
Repair Solution: Most likely high-strength epoxy injection to restore structural integrity.
Concrete Expansion Cracks
Expansion cracks develop when concrete expands due to heat, exerting pressure on the structure. Like most materials, concrete expands when heated, and if it lacks sufficient space to expand, the resulting internal stress can cause cracks. Expansion joints are often installed to provide relief and absorb the stress of expanding concrete.

Cause: Thermal expansion without adequate expansion joints.
Repair Solution: Polyurethane foam injection, which is flexible enough to accommodate movement.
Heaving Cracks in Concrete
Heaving cracks typically occur in cold climates where freeze-thaw cycles are common. When water within the concrete freezes, it expands considerably, causing the concrete slab to lift or “heave.” As temperatures rise and the ice melts, the slab settles back down, leading to the formation of cracks due to the constant movement. This can be prevented by allowing space for expansion and contraction.
Cause: Freeze-thaw cycles and temperature changes.
Repair Solution: Flexible polyurethane foam that can expand and contract with temperature variations.
Crazing and Crusting Cracks in Concrete
Crazing refers to shallow, fine cracks resembling spider webs that appear due to premature drying. Crusting, on the other hand, occurs when the top surface dries faster than the bottom during stamping. While these cracks are not usually structural concerns, they can impact aesthetics and lead to moisture ingress.
Cause: Uneven drying during the curing or stamping process.
Repair Solution: Low-viscosity polyurethane foam for sealing and moisture protection.
Disintegration Cracks in Concrete
Disintegration cracks are a result of the gradual breakdown of concrete, starting with surface scaling and leading to large pieces breaking away. Disintegration often results from chemical attacks like carbonation or sulfate exposure and poor construction practices.
Cause: Chemical attacks or poor-quality aggregates.
Repair Solution: High-strength epoxy injection to reinforce the structure and sealant application to prevent further chemical exposure.
Re-Entrant Corner Cracks in Concrete
Re-entrant corner cracks occur at areas with abrupt changes in geometry, such as around columns, pipe penetrations, sharp corners column bases, pipe penetrations, around rounded objects like manholes, and intersections where slab and wall joints meet. As the concrete dries, uneven shrinkage around these regions creates stress concentrations that lead to cracking.
Cause: Stress concentration around corners or openings.
Repair Solution: Polyurethane resin, foam injection, depending on the severity and circumstances, to seal the cracks, prevent moisture ingress, or, epoxy injection to regain structural strength.
Alkali-Silica Reaction (ASR) Cracks in Concrete
Alkali-Silica Reaction (ASR), also known as concrete cancer, is a harmful chemical reaction between highly alkaline cement paste and reactive silica in aggregates. This reaction produces a hygroscopic gel that absorbs water, expands, exerts internal pressure, and progressive loss of concrete strength leading to map cracking, also known as pattern cracking or alligator cracking. This distinct crack pattern consists of randomly-oriented, web-like cracks on the surface of concrete elements that move in multiple directions.
Cause: Reaction between alkaline cement and reactive silica.
Repair Solution: Polyurethane resin, foam injection, depending on the severity and circumstances, to seal the cracks, prevent moisture ingress, or epoxy injection to regain structural strength.

Choosing the Right Repair Method for many Types of Concrete Cracks

When selecting a repair method for different types of cracks, consider the crack’s cause, size, and impact on the structure:

Polyurethane Foam and Resin Injection: Ideal for flexible sealing in areas with moisture issues and minor movements. Works well for sealing finest cracks as well as large voids or areas prone to temperature changes, due to its expanding and flexible properties.
Acrylate Gel: Perfect for curtain injection and super fine hairline cracks.
Epoxy Injection: Best suited for structural repairs of cracks requiring high strength and load-bearing restoration.

Conclusion

Concrete cracks are an inevitable challenge for any concrete structure due to the diverse range of factors that can cause them, such as environmental conditions, structural issues, and material weaknesses. Understanding the different types of concrete cracks, such as shrinkage cracks, plastic shrinkage cracks, spalling, D-cracking, and more, is crucial for professionals tasked with maintaining the structural integrity of concrete elements.

By recognizing the root causes of these cracks, repair professionals can determine the most effective methods for restoration. For example, structural cracks due to overloading or stress corrosion may require high-strength epoxy injection to restore the original load-bearing capacity, while cracks resulting from freeze-thaw cycles or moisture ingress are better addressed using flexible polyurethane foam injections. For fine hairline cracks or moisture control in large sections, acrylate gels provide a versatile and efficient solution.

Proper selection of repair materials and techniques not only helps in addressing visible damage but also aids in preventing future deterioration, extending the life of the concrete structure. Each crack type demands careful evaluation to choose the right repair approach, ensuring both safety and durability.

Polymer-based injections, including polyurethane resins, foams, acrylates, and epoxies, offer comprehensive solutions for addressing a wide variety of concrete cracks. They provide the versatility to handle anything from superficial fine cracks to deep structural fissures, making them indispensable for professionals committed to maintaining the integrity of concrete elements.

By integrating these repair methods into their toolkit, professionals can confidently tackle any concrete crack repair challenge, ensuring long-term durability and safety for the structures they manage. As always, consulting experts and selecting high-quality products for each specific application remains key to achieving successful and lasting results.

To learn more about how to approach specific concrete crack repair projects, explore our Concrete Crack Repair Quick Guide

Concrete Crack Repair – A Quick Guide to Polymer Grout Injection

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Manhole Repair – Leak Sealing Injection

Manhole Repair
Leak Sealing Injection

Manhole Repair Systems

SealBoss provides comprehensive system solutions aimed at rehabilitating manholes and repairing leaks, effectively sealing water leaks occurring via cracks, joints, and annular pipe intrusions. Leveraging our repair systems allows for a considerable extension of a manhole structure’s service life, all the while maintaining cost-effectiveness.

Addressing Manhole Damages and Blockages through Inspections and Repairs

Mitigating Infiltration and Inflow (I/I) in Manholes

Manholes are frequently subjected to I/I, which manifests as infiltration through cracks and joints, and inflow of groundwater. These occurrences can significantly elevate treatment costs and contribute to environmental pollution. Furthermore, they may trigger soil and groundwater contamination, sinkholes, and damage to roads and structures.

To prevent and correct these issues, it is crucial to conduct regular inspections and necessary repairs on manholes.

SealBoss provides a selection of cost-effective systems designed to repair manholes, successfully addressing typical and common forms of damage.

If left untreated, deteriorating and leaking manholes can result in substantial, highly expensive damage to both the environment and infrastructure.

Understanding Sanitary Sewer Overflows (SSOs)

Sanitary sewer overflows (SSOs) represent a pressing environmental and public health issue. These overflows, saturated with untreated sewage, act as conduits for bacteria, viruses, and other pathogens.

At times, sanitary sewers may inadvertently discharge untreated sewage, leading to what’s termed as an SSO. Such overflows can not only taint our water sources, resulting in significant water quality degradation but also backflow into residential areas. This not only damages property but also poses a substantial health risk to the public.

Factors Leading to SSOs:

Blockages in the sewer lines
Ruptures or breaks in the sewer lines
Structural defects that permit storm water and groundwater to inundate the system
Power outages affecting the sewage system’s operations.
Flaws in the sewer system’s design
Acts of vandalism disrupting the system

According to data from the Environmental Protection Agency (EPA) as of September 2023, it’s estimated that the U.S. experiences between 23,000 to 75,000 SSO incidents annually. This figure excludes sewage backups into buildings, underscoring the gravity of the issue.

Identifying Common Manhole Failure Causes

Several common causes of manhole failure include:

Infiltration via precast joints
Leakage from precast manhole rings
Groundwater intrusion through cracks
Infiltration via mortar joints
Cracks resulting from shifting soil, traffic load, or soil expansion
Fissures due to micro-biological corrosion

Manhole Repair Using Injection Grout

Addressing Different Types of Manholes – Brick, Precast and Combination Manholes

SealBoss Injection Systems are designed to accommodate manholes constructed from a range of materials.

Introducing the ealBoss Seal-Oakum / Oakum Soakum Technique

e recommend having SealBoss Seal-Oakum on-site to effectively plug larger voids and joints. The Oakum Soakum Technique is explained here.

Understanding Basic Repair Procedures

Repairing Manhole Leaks through Larger Cracks and Brick Construction

Here are the steps:

Drill through the structure to the outside of the manhole to fill any voids and crate a curtain behind the structure
Install Injection Packers
Prior to injection, repair wide pipe penetrations using Seal-Oakum
Start injection at the bottom

Adressing Manhole leaks through Precast Manhole Rings / Joints

Follow these steps:

Drill injection holes into the manhole rings approximately every 60 degrees
Install six injection packers. In case of severe leaks, more drill holes/packers may be required
Prior to injection, repair wide pipe penetrations and broad ring joints using Seal-Oakum
Start injecting process from the bottom

Manhole Inspections and Preventive Maintenance – The Key to Longevity

Regular inspection of manholes is crucial to identify issues early and prevent them from escalating. Implementing a preventive maintenance program for manholes can prevent costly repairs and extend their lifespan. Regular cleaning, sealing of cracks, and routine inspections can ensure their proper function and prevent I/I.

Innovative System Solutions with SealBoss

SealBoss provides a wide-ranging selection of manhole repair solutions. This includes a variety of injection systems, water-reactive grouts, structural resins, SealBoss Seal-Oakum, along with injection packers and pumps. These tools are designed to confront a broad spectrum of manhole issues, proving their effectiveness across diverse manhole designs and construction materials.

Conclusion

Addressing the issue of manhole damage is essential for efficient sewage management, environmental preservation, and safeguarding infrastructure. Regular inspections, timely repairs, and effective maintenance procedures can help manage these concerns. At SealBoss, we provide innovative and economical solutions tailored to meet these needs.

Manhole Repair System Example

Experience Hands-On Training with SealBoss P2002 Pro Kit System

We provide comprehensive, hands-on training in the application of high-pressure polyurethane water stop foam injection, using the SealBoss P2002 single-component injection pump, or any other SealBoss Injection System specified.

The equipment and materials used in this training include SealBoss 1510 Water Stop Foam, SealBoss AL 13-100 (½”) high-pressure packers, and SealBoss Seal-Oakum.

During the training, a SealBoss technical expert will be present on-site to provide direct support to the contractor. Our primary goal is to ensure that your work crew gains confidence and comfort in using the application.

TOur training covers the full spectrum of the application process. This includes instruction on pump usage, packer installation, the detailed injection procedure, and the clean-up process. We also educate repair crews on how to apply catalyzed resin-soaked SealBoss Seal-Oakum effectively.

If you have any questions regarding manhole repair, our team of proficient SealBoss representatives is ready to assist. Feel free to contact us to schedule an on-site consultation and comprehensive training on injection systems.

Manhole Repair Crew Training

Manhole Repair System Example

SealBoss Manhole Repair

Click Here

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Crack Injection Tools & Accessories

Crack Injection Tools & Accessories: Your Ultimate Source for Professional-Grade Solutions

As a leading supplier of concrete crack repair solutions, we are excited to offer an extensive selection of crack injection tools and accessories designed to meet the needs of both low and high-pressure injection systems.

Our product line is engineered to support a wide range of project requirements, ensuring that whether you’re working on large-scale commercial projects or smaller residential repairs, you have access to the tools you need for success.

From experienced contractors to first-time repair professionals, our comprehensive range of high-quality components ensures that your crack repair toolkit is fully stocked, enabling you to execute foundation crack repairs with confidence and precision

Why Choose Our Crack Injection Tools & Accessories?

Versatile Solutions: We cater to both low and high-pressure injection systems, providing flexibility for a variety of applications, from minor cracks to significant structural repairs.
High-Quality Components: Every item in our product line is crafted with durability and efficiency in mind, giving you the tools you need for successful, long-lasting repairs.
Suitable for All Experience Levels: Whether you’re a seasoned professional or tackling crack injection for the first time, our tools are designed for ease of use without compromising performance.

Elevate your crack repair work with our Crack Injection Tools & Accessories – because successful foundation restoration starts with having the right tools.

Pumps

Injection Lances / Needles

Applicators

Hose sets

Crack Injection Hand Tools

Injection Packers

Couplers / Fittings

Surface Ports

Injection Tube System

Static Mixers

SealBoss Seal Oakum

Crack Injection Tools & Accessories – Dependable Solutions for Every Project

At the core of our offering is a commitment to providing reliable and effective crack injection tools and accessories that ensure your repairs stand the test of time. We recognize that no two projects are the same, which is why our range has been carefully curated to meet the diverse requirements of low and high-pressure injection systems.

Regardless of your level of experience, our tools are engineered to help you achieve professional results. From injection ports to specialized pumps and accessories, each item is designed to make the process smoother, more precise, and ultimately more successful.

Unmatched Technical Support

In addition to offering premium products, we are dedicated to ensuring you have the support you need to use them effectively. Our expert technical support team is available to provide guidance, answer any questions, and help you make informed purchasing decisions. Whether you need advice on selecting the right tools or troubleshooting during the repair process, we are here to ensure your foundation restoration is completed with the utmost precision and efficiency.

Your success is our success, and we stand behind every product we offer with unparalleled after-sales support. Trust us to help you achieve flawless crack repairs, every time.

Start your foundation restoration journey with our Crack Injection Tools & Accessories — because lasting success begins with the right tools.

Contact Your SealBoss ® Technician

Polyurethane Foam Injection

Introduction:

Polyurethane foam injection has become a cornerstone technique in concrete repair and waterproofing, offering unmatched flexibility, durability, and efficiency. This innovative method seals cracks, stabilizes foundations, and protects below-grade structures from water intrusion—all without the need for invasive excavation. In this article, we explore the intricacies of polyurethane foam injection, from its applications and benefits to the step-by-step process and comparison with other repair methods, providing a comprehensive guide for industry professionals seeking reliable and long-lasting solutions.

Polyurethane Foam Injection: The Definitive Guide to Concrete Repair and Waterproofing

Polyurethane foam injection for crack repair and soil treatment has revolutionized the field of concrete repair and waterproofing, offering reliable and long-lasting solutions for a wide range of structural problems. This advanced technique effectively seals cracks, stabilizes foundations, and prevents water intrusion, making it a preferred choice among industry professionals. This comprehensive guide will delve into the key aspects of polyurethane foam crack injection, its applications, benefits, processes, and how it compares to other crack repair methods.

Polyurethane Foam Injection Systems and Applications

1. Understanding Polyurethane Foam Crack Injection and soil Injection Treatments

Polyurethane foam crack injection involves injecting a reactive foam into cracks, voids, or joints in concrete structures. The polyurethane resin expands upon contact with water, forming a flexible, closed-cell foam that seals leaks and prevents water from entering the structure. This method is particularly effective for below-grade waterproofing, foundation crack sealing, and repairing structural cracks caused by settlement, shrinkage, or hydrostatic pressure.

2. Key Applications of Polyurethane Grout Injection

Polyurethane foam injection is versatile and suitable for a variety of applications in both residential and commercial settings:

Foundation Crack Sealing: Polyurethane injection effectively seals foundation cracks, preventing water infiltration and reinforcing structural integrity. It addresses cracks caused by settlement, shifting, or external water pressure, ensuring a long-lasting repair.
Basement Waterproofing Injection: This technique is ideal for waterproofing basements by sealing cracks and joints in foundation walls and floors. Polyurethane foam injection creates a watertight barrier, preventing water seepage and protecting the interior from moisture damage.
Curtain Wall Grouting: Curtain wall grouting involves injecting polyurethane foam behind the structure, creating a water barrier on the positive side. This method is highly effective for large-scale waterproofing projects, such as tunnels, retaining walls, and below-grade structures.
Bladder Injection Method: In the bladder injection method, foam is injected into voids and gaps behind concrete walls, forming a bladder-like seal that blocks water intrusion. This technique is especially useful in areas with high hydrostatic pressure.
Slab Lifting and Stabilization: Polyurethane injection is also used to lift and stabilize uneven slabs. Known as slab jacking, the expanding foam fills voids under the concrete, restoring stability and levelness without the need for extensive excavation.

3. Types of Polyurethane Foam for Crack Injection

Polyurethane foams used in crack injection are categorized based on their properties and applications:

Hydrophobic Polyurethane: Hydrophobic foams repel water and are ideal for sealing large cracks and voids. They expand minimally, providing a dense and durable seal without absorbing moisture.
Hydrophilic Polyurethane: Hydrophilic foams absorb water and expand significantly upon contact, making them suitable for sealing fine cracks and creating flexible seals in dynamic environments. These foams are particularly useful in curtain wall and bladder injection applications where thorough penetration is required.

4. The Injection Process: Step-by-Step Overview

The polyurethane foam crack injection process is a systematic approach that ensures effective sealing and waterproofing:

Surface Preparation: The area around the crack is cleaned to remove debris, dust, and loose particles, ensuring optimal adhesion of the foam.
Crack Evaluation and Drilling: The crack is assessed to determine its size, condition, and water activity. Holes are drilled at regular intervals along the crack to allow for the installation of injection packers.
Installation of Injection Packers: Packers are inserted into the drilled holes, providing a secure entry point for the foam injection.
Injection of Polyurethane Foam: Polyurethane resin is injected through the packers under controlled pressure. The foam expands within the crack, filling all voids and creating a watertight seal.
Curing and Final Inspection: The foam begins to cure immediately, expanding to fill the entire crack. A final inspection ensures that the crack is fully sealed and no voids remain.

5. Advantages of Polyurethane Foam Injection

Polyurethane foam injection offers numerous advantages over traditional crack repair methods, making it a preferred choice for professionals:

Flexibility and Adaptability: Unlike rigid materials, polyurethane foam remains flexible after curing, allowing it to accommodate minor structural movements without compromising the seal.
Water Resistance: Polyurethane’s hydrophobic properties ensure that the foam repels water, maintaining its integrity even in wet conditions.
Minimal Disruption: The injection process can be performed from the inside, avoiding the need for extensive excavation or structural modifications.
Quick and Efficient: Polyurethane injection is relatively fast, often completed within a few hours, minimizing downtime and disruption.
Long-Lasting Solution: The foam creates a permanent seal that resists environmental factors, unlike patches or surface applications that often fail over time.

6. Comparative Analysis: Polyurethane vs. Other Crack Repair Methods

Polyurethane foam injection is often compared to other crack repair methods, such as epoxy injection and hydraulic cement patching:

Epoxy Injection: While epoxy is strong and ideal for structural repairs, it lacks the flexibility needed for dynamic environments. Epoxy also requires dry conditions, limiting its effectiveness in actively leaking or wet cracks. Polyurethane, by contrast, excels in both wet and dynamic conditions.
Hydraulic Cement Patching: Hydraulic cement requires chiseling out the crack into a vee-notch, which is labor-intensive and often fails over time due to poor adhesion. In contrast, polyurethane fully penetrates the crack and bonds tightly to the surrounding concrete, providing a more reliable and permanent solution.

7. Equipment and Tools for Polyurethane Injection

Successful polyurethane crack injection relies on specialized equipment designed for precise and controlled application:

Injection Packers: These are installed in drilled holes along the crack and serve as entry points for the foam. Packers can be mechanical or hammer-in types, depending on the pressure requirements of the injection.
Injection Guns and Pumps: High-pressure pumps deliver the polyurethane resin into the cracks. These pumps can be adjusted based on the size and complexity of the crack, ensuring efficient foam distribution.
Mixing Systems: Some polyurethane foams require precise mixing of components before injection. Advanced mixing gear maintains correct ratios, enhancing the performance and consistency of the foam.

8. Safety Considerations and Environmental Impact

Handling polyurethane foams requires strict adherence to safety protocols to protect workers and the environment:

Protective Gear: Operators must wear gloves, goggles, and respirators to minimize exposure to chemicals during the injection process.
Proper Ventilation: Even though high quality foams do not contain VOC`s or solvents, adequate ventilation is necessary to disperse any fumes generated during the injection, especially in enclosed spaces.
Eco-Friendly Options: Environmentally friendly polyurethane foams are available, minimizing the impact on the surrounding ecosystem. Responsible disposal of waste materials and adherence to environmental standards contribute to a sustainable injection process.

9. Innovative Uses and Future Developments in Polyurethane Injection

Polyurethane foam injection continues to evolve, finding innovative applications beyond traditional concrete repair:

Industrial Applications: Polyurethane is used to stabilize machinery pads, fill voids around pipelines, and reinforce infrastructure in industrial settings, demonstrating its versatility.
Geotechnical Solutions: Polyurethane is ideal for stabilizing soil, filling voids, and preventing erosion around underground utilities, aligning with sustainability goals.
Ongoing Research: Continuous advancements in polyurethane technology focus on improving performance, reducing curing times, and enhancing environmental sustainability.

10. Cost Analysis and Economic Benefits

Understanding the costs associated with polyurethane injection is essential for making informed decisions:

Direct Costs: The direct costs of polyurethane injection include materials, labor, and equipment. While these costs can be higher compared to simpler methods like patching, the long-term benefits in most scenarios outweigh the initial investment.
Low Indirect Costs: Polyurethane injection typically requires minimal service interruptions, reducing indirect costs related to downtime and additional repairs.

11. Addressing Common Challenges and FAQs

Below are common questions and concerns related to polyurethane foam injection:

Can polyurethane injection be used in all crack types?
While highly versatile, polyurethane is best suited for non-structural and waterproofing applications. For structural repairs, epoxy may still be preferred due to its strength. Read our comprehensive Epoxy vs Polyurethane comparison here.
How does polyurethane perform in extremely wet conditions?
Polyurethane foam excels in wet conditions, particularly hydrophilic variants that react and expand upon water contact, ensuring thorough sealing even in high-moisture environments.
What are the potential downsides?
There are few downsides to polyurethane foam injection. Quality product paired with proven equipment and a professional and experienced contractor is the best foundation for quick and lasting repair. The primary concerns with polyurethane injection are related to proper mixing and injection techniques. Incorrect procedures can lead to incomplete seals or incomplete penetration / expansion, emphasizing the need for skilled application and suitable equipment.
Is polyurethane injection a permanent solution?
Yes, when properly applied, polyurethane injection provides a permanent seal. Its flexible and inert nature allows it to adjust to minor structural movements, as well as temperature related expansion and contraction cycles, preventing future water intrusion.

Conclusion

Polyurethane foam crack injection is a cutting-edge technique that provides durable, flexible, and efficient solutions for concrete crack repair and waterproofing. Its adaptability to various conditions, combined with minimal disruption and long-lasting results, makes it a standout choice for professionals seeking reliable methods to address structural and water infiltration issues. As the industry continues to advance, polyurethane foam injection will remain at the forefront of innovative concrete repair technologies, setting the standard for effective and sustainable building maintenance.

For more information on our products and services contact our expert team today!

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PU Foam Injection Systems

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SealBoss in Australia

SealBoss in Australia 2024

Back Down Under by Popular Demand

SealBoss 6500 UVR

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Joint Filler

NEW For Australia
SealBoss 6500 UVR

UV-Resistant Polyurea Floor Joint Filler

SealBoss 6500 UVR represents the newest generation the latest advancement in polyurea joint fillers, specifically engineered to resist fading and color change under the influence of ultraviolet light.

This innovation ensures long-term performance and durability, making it an ideal choice for various applications, particularly in environments with UV exposure.

SealBoss in Australia – Training Tour

It’s that time again – we are headed back down under for an extended and comprehensive training tour nothing short of, as they say in Australia, BONZER!

We are visiting with SealBoss Distributor Bayset and their customers at many of the now thirteen Bayset locations, including Brisbane, Townsville, Melboune, Sydney, and Canberra.

Bayset’s ongoing expansion has many new locations of theirs on the itinerary this go around which will have SealBoss Regional Manager Chris Coderre busier than a Koala in an Eucalyptus forest.

Training sessions will include in-depth classroom style presentations with Q&A as well as hands-on product training using the CUBE demo modules at the locations on the tour.

Check Out our Proven and New for Australia UV Resistant Polyurea Floor Repair SealBoss 6500!

Our SealBoss Injection Systems Line including foams, gels and accessories, along with the QuickFix Floor Repair Product Line (inclusive of our super fast polyurea joint fillers and JointMaster pumps) are available for you at Bayset.

SealBoss in Australia - Bayset

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australia

Curtain Injection In Pictures

Curtain Injection in Pictures

And Podcast

Curtain / Bladder Injection - Curtain Wall Grouting Method

Water intrusion is a persistent challenge for below-grade concrete structures, where traditional patching and surface sealers often fall short. The failures of these surface-applied remedies—such as patches, liquid sealers, and membrane applications—stem from their inability to address the root causes of leaks. These methods provide only temporary relief, leaving structures vulnerable to recurring hydrostatic pressure and ongoing water damage.

Curtain wall grouting, including advanced techniques like curtain and bladder injections, offers a reliable, long-term solution to these challenges. Unlike surface treatments, these methods work by creating a robust waterproof membrane and water barrier behind the structure. This approach not only seals cracks and cold joints from within but also fortifies the structure against future water intrusion.

By injecting specialized grouts through the structure to form a protective layer on the positive side, curtain injection ensures a comprehensive and lasting seal. Whether applied through stage grouting or other targeted injection methods, this professional approach delivers durable protection, minimizing service interruptions and maximizing cost-effectiveness in the long run.

Curtain / Bladder Injection is the Reliable Way to Waterproof Your Below Grade Concrete Structure Permanently

Why Patches and Liquid Sealers Often Don’t Stand the Test of Time

Experiencing the frustration of failing patches and paint applications on damp, actively leaking, below-grade structures is something many of us can relate to.

These are typically failed attempts to block hydrostatic water intrusion using surface-applied remedies that serve as temporary solutions at best.

Interior patches and membrane applications, while seemingly addressing the problem, often don’t tackle the root cause and rarely provide a lasting waterproofing resolution.

A Professional Approach to Curtain Injection:

Sealing Cracks Permanently and Establishing a Waterproof Membrane and Water Barrier behind the Structure

Water leakage via cold joints, cracks, and other irregularities in concrete can frequently only be effectively and permanently sealed using advanced injection techniques, such as curtain, bladder, and stage grouting injection methods.

The SealBoss Injection Product offers a professional solution to these issues, filling and sealing the cracks from the inside out. This product is injected through the structure, forming a membrane on the structure’s positive side, thus providing a more effective and lasting waterproofing solution.

The Art of Stage Grouting Technique

In complex grouting scenarios, the stage grouting technique is often the favored approach. This process entails a strategic series of injections carried out in a staged manner, utilizing lower volumes of product in each application.

Each stage of this meticulous process is allowed sufficient time to react, allowing the grout to solidify and establish a natural barrier before proceeding with the subsequent stage of grouting. This carefully phased and controlled deployment not only elevates the overall efficacy of the grouting operation but also ensures thorough and consistent coverage along the exterior of the wall.

Comparative Cost Analysis of Injection Grouting Sealing Methods

Understanding the financial impact of various sealing techniques is essential for making cost-effective decisions. Below is a comparison.

Crack Injection

Direct Costs: Moderate for materials and labor, product is injected directly into the cracks, joints, and voids. Low for equipment.
Indirect Costs: Minimal, as the method is fastest and causes little service interruption.

Curtain Grouting

Direct Costs: Higher for materials and labor, product is injected through the structure into the substrate behind, which results in higher material consumption. Packers are set in distinctive patterns. Moderate for equipment.
Indirect Costs: Higher, due to the lengthier process of preparation and product pumping, which can lead to more significant service disruptions.

Links

Curtain / Bladder Injection Products

Professional Polymers

Premium Packers

Powerful Pumps

SealBoss Injection Pump Systems

Mockups
Curtain Wall Grouting | Negative Side Injection Waterproofing

"The Mockup is Worth its Weight in Gold"
Technical Podcast for the Infrastructure Repair Industry

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Injection Brochure

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Restoration Waterproofing

Restoration - Waterproofing

Restoration – Waterproofing with Injection Resins, Gels, and Foams

Restoration waterproofing projects represent a mix of various complex tasks, each with its unique set of challenges. The first crucial step is identifying the root source of the water infiltration, which at times can be a difficult process.

Diagnosis

A correct leak diagnosis might necessitate various steps, such as performing visual inspections of the inside and outside of the structure, examining the surrounding conditions, conducting flood tests, utilizing dye testing, creating mock-ups, and removing paints and finishes.

Waterproofing Restoration with SealBoss Water Stop Systems
– Resins, Foams, Gels, Packers and Pumps –

Setting Defined Objectives

Before starting a restoration waterproofing project, it is crucial to clarify the goals and expectations for every party involved.

It goes without saying that the primary aim of such a venture typically revolves around halting water intrusion. There are many techniques and products that can be used for this, such as polyurethane injection foams, gels, and resins, as well as acrylate injection gels and even epoxy resins in some circumstances. These methodologies come with their individual costs, levels of site disruption, and project timetables. It is essential that all of these elements are thoroughly considered and presented to the end customer, facilitating an informed decision-making process.

Understanding Water Movement and Migration

It is indispensable to understand some key concepts related to water migration and movement around and within soil, structures, voids, joints, and cracks.

Water is Not Always Visible

The obvious appearance of a leak in a specific location does not definitively imply that other areas are devoid of water ingress. Water invariably seeks the path of least resistance, typically navigating towards any openings, fissures, and low spots. Upon remediation of these lower areas, the water may find its way to other compromised zones.

Leak Detection Techniques

The leak detection process is further complicated if the repairs are undertaken during a period of relative dryness. Under such circumstances, leak migration might not become evident until the advent of the next rain event. For more controlled testing, it may be advisable to deliberately flood the surrounding area, creating conditions that could induce a leak at the time of inspection and repair. Conducting flood testing before, during, or after the repair work can contribute significantly towards pinpointing any areas where the leak may have migrated. Executing waterproofing repairs amidst active leaking can effectively help identify and repair leak migration issues.

Restoration Waterproofing Products

Polymer injection foams, resins and gels serve as viable solutions in restoration waterproofing. Their superior qualities make them ideal for sealing leaks, even in wet environments. Polyurethane foams are adept at sealing large leakages, both in volume and speed, expanding upon contact with water to block infiltrations effectively. On the other hand, super low viscosity resins and gels ensure a long-lasting solution for smaller, more intricate leaks, seeping into hairline cracks and curing to provide a waterproof seal. Implementing curtain injection behind a structure can effectively generate a waterproof, membrane-like barrier, thus sealing wet and damp spots within concrete and masonry structures.

At times, epoxy resins may be required to restore structural integrity, even in wet or damp conditions. For an in-depth comparison between epoxy and polyurethane injection, please refer to the detailed information provided here.

In Conclusion

Remedial restoration waterproofing is often an iterative, exploratory process that might necessitate adjustments along the way. Setting realistic expectations, keeping open lines of communication among all involved parties, and maintaining a keen eye for detail are important to the efficient and successful execution of a waterproofing process.

A well-executed waterproofing restoration can add years to the lifespan of a structure, safeguarding it against potential damage and preserving its aesthetic and functional value.

Restoration – Waterproofing Systems

Popular Water Stop & Leak Sealing Injection Links

SealBoss ® 1510

Leak Sealing Foam Grout
Water Stop Foam Grout
Hydrophobic Injection Foam Grout

Our #1 Selling Polyurethane Injection Foam
Water Cut-Off Injection Grout
1510 PU Foam & Oakum Pipe Plug Kit

SealBoss ® 1570

Leak Sealing Foam Grout
Water Stop Foam Grout
Hydrophobic Injection Foam

Flexible Polyurethane Injection Foam
Flexible Foam, Water-Activated chemical grout.

SealBoss ® 1570 LV

Leak Sealing Foam Grout
Water Stop Foam Grout
Hydrophobic Injection Foam

Super Low Viscosity Polyurethane Injection Foam,
Water-Activated chemical grout. Drinking Water

SealBoss ® 15X ACCELERATOR

Accelerator for SealBoss Single Component Injection Foams

Accelerator For 1510/1570 PU Injection Foam. Adjust foam gel-time and foam expansion from low foaming to high foaming depending application.

SealBoss ® 1403 SLV

Leak Sealing Injection Resin
Super Low Viscosity PUR Injection Resin

Two Component Flexible Resin
The solution for wet and dry surfaces and moving cracks. Extremely low viscosity for superior penetration in hairline crack injection.

SealBoss ® FLEXGEL

Leak Sealing Injection Gel
Hydrophilic Injection Foam Gel
Hydrophilic Gel

Versatile Hydrophilic Polyurethane Foam-Gel
Water activated single component hydrophilic Polyurethane grout.

SealBoss ® 2400

Leak Stop
Leak Sealing
Acrylate Gel
Acrylic Gel

Poly Acrylate Gel
Hydrophilic poly-acrylate gel / acryclic gel for soil stabilization, curtain-injection, infusion bladder injection into structures and to seal degrading masonry grout.

Restoration - Waterproofing

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Water Stop

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Pool Crack Repair

Swimming Pool Crack Repair

Introduction

Discover the definitive solution for swimming pool crack repairs with our SealBoss Polyurethane Injection Foam Pool Crack Repair Products and Kits.

Our professional-grade crack injection method offers a permanent, robust solution that extends beyond mere cosmetic fixes.

Utilizing high-density, NSF/ANSI 61 certified polyurethane foam, our system not only seals but strengthens pool structures, ensuring a long-lasting repair that withstands environmental stress and hydrostatic pressure.

Perfect for concrete, gunite, shotcrete, and pebble tech finishes, this method delivers both functionality and aesthetic satisfaction, providing peace of mind to pool owners.

Cause of Damages

Pool cracks caused by the settlement of back fill, poor soil condition in general and stressed concrete can lead to leaks, worsening structural damages and water related damages to nearby structures.

Swimming Pool Crack Repair Solution

Contrary to the misconception by some pool owners that crack injection just provides a temporary patch-up, professional water stop leak sealing injection repair actually provides a lasting fix.

This method makes use of a high-density polymer foam, which holds the NSF/ANSI/CAN 61 Certification, validating its safety for interaction with drinking water. During the injection phase, the foam product effectively penetrates deep into the structure while sealing every crevice and crack in the process.

As the polyurethane foam encounters moisture, it expands, infiltrating each crack and crevice during the pressure injection process. This ensures that it effectively plugs the full thickness of a concrete pool wall, making for a comprehensive repair.

Once it cures, this inert, waterproof resin maintains its volume and remains flexible, unaffected by standard ground movements and temperature fluctuations. Therefore, the possibility of shrinkage, a common issue with other solutions, is not a concern. This method of repair is built to last, providing you with a durable and reliable fix for your concrete structures. This ensures that they can satisfy both functional requirements and aesthetic preferences.

SealBoss Polyurethane Injection Foam Pool Crack Repair Products and Kits permanently repair leaking cracks and joints in concrete, gunite, shotcrete and pebble tech finished swimming pools and spas.

Negative Side Crack Injection is Conveniently Performed from the Inside of the Structure

For this type of Leak Sealing Repair, SealBoss Pool Crack Repair Kits provide an effective, easy to use water stop / leak sealing crack repair solution by creating an airtight and watertight hydrophobic seal that repels water once cured. Polyurethane injection foam systems are designed to work in wet environments.

The pool leak sealing repair kit includes a SealBoss P2002 high-pressure injection pump, SealBoss 1510 hydrophobic resin with 15x catalyst and SealBoss mechanical Injection Packers which when used together allows the user to displace the hydrostatic pressure and fill the crack with a foam that reacts from the moisture present.

Key Features:

Permanent swimming pool crack repair for leaking concrete, gunite, shotcrete and pebble tec finished pools and spas
Permeates into cracks and fissure, plugging the entire thickness of the concrete
SealBoss 1510 high-density, hydrophobic polyurethane foam expands — creating a compression seal
NSF/ANSI 61 Drinking Water Contact Certified

Pool Crack Repair – Water Stop & Leak Sealing Injection Pro Kit

Injection Resin: SealBoss 1510 w/ 15x Accelerator | NSF/ANSI 61 Drinking Water Contact Certified
Injection Packers: 1/2” 13-100 Evolution Aluminum Packers
High Pressure Pump: P2002 Single Component Injection Pump
Cleaning: R70 Pump Flush

Popular Water Stop & Leak Sealing Injection Links

Structural Repairs and Inspections

While in most cases PU injection is the repair of choice to permanently seal water bearing cracks in concrete structures, there is sometimes the need for a structural repair.

For structural repairs, please refer to the SealBoss Epoxy Injection System and Epoxy Repair Kits. You may also want to read our Epoxy versus Polyurethane article for in-detail information.

Please be advised that any underlying and all ongoing causes of structural damages, formation of cracks and settling — including, but not limited to, back fill settlement and poor soil density — should be investigated by a specialist and corrected, if deemed necessary. For additional information on Swimming Pool Soil Settlement click here.

Pool Crack Injection Systems

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Pool Soil Settlement

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Contact Your SealBoss ® Technician

Seawall Repair with Polyurethane Foams | Plural Component vs Single Component Foam

Seawall Repair with Polyurethane Foams
Plural Component vs Single Component Foam

Concrete Solutions Since 1988

This article contains an excerpt from the “SealBoss Concrete Solution Network Podcast – Seawall Repair | Bulkhead Repair | Erosion Control | Permeation Grouting”, featuring Jerald Sargent of Slabjack Geotechnical. Jerald has over 30 years of experience in the slabjacking and geo-technical industry. If you’d like to listen to the complete conversation, an audio version of the podcast is posted at the bottom of the article.

In this podcast we talk about the use of single and plural component foams for seawall repairs.

Both foam types have their place in seawall repair but the contractor needs to have a good understanding of their respective characteristics and area of application.

Single component (accelerator activated) foams offer outstanding crack sealing and good soil penetrating, permeation and soil aggregate stabilizing properties.

Plural component foams are excellent void fillers, support and lifter foams, predominantly used for slabjacking and slab lifting.

Single Component Foams are Preferred for Soil Permeation and Soil Consolidation — Plural Component Foams are Good for Filling Voids in Certain Applications

In the following Jerald discusses the use and limitations of Plural Component Foam.

Jerald Sargent: …Sometimes plural components make a lot of sense… where there’s obvious gaps behind the wall or maybe in a you know in a big boulder type of Bulkhead where they just use big rock rather than poured concrete. So plural components are good for filling voids in there and helping to lock [larger] aggregate together…

In most poured concrete walls we stay away from plural component simply because of the risks associated with it.

Going right along with that, one of the things that plural component is not appropriate for is injecting underneath the walls…

There’s virtually no permeation [into the soil] involved with plural component polyurethanes. It’ll [the soil] take up, it’ll absorb a little bit push through a little bit of that but it will not do it to the point where you have a solid structure built below the wall itself.

And I think that it is really important to understand the real limitation of the plural component polyurethane. And we use hundreds of thousands of pounds of a year in our slapjack in operation.

But it really isn’t appropriate in most cases to do a poured concrete wall [soil] stabilization.

To learn more about seawall repair and single and plural component foams you may want to listen to the podcast below.

Looking for a seawall repair contractor? – Call us at 714-662-4445.

Seawall Repair with Polyurethane Foam