Alchatek Blog

A tunnel structure in the Mobile, Alabama area had persistent water infiltration at the interface between concrete and metal components. The leak was traced to a tight crack at the joint, allowing water to migrate into the tunnel and cause visible staining, as well as potential long-term deterioration. The client sought a solution that would seal the leak without requiring major demolition or extended tunnel closure.

Initial Assessment

Visual inspection and on-site review identified the leak path at the interface between the concrete and metal. The crack width was measured between 0.2 and 0.3 mm, indicating that traditional cementitious grouts or surface sealants would not be effective. The challenge was to deliver a material that could penetrate deep into the joint and expand to form a watertight seal, even in confined spaces and around embedded metal.

Proposed Solution

Alchatek recommended Spetec PUR F400, a low-viscosity, hydrophobic polyurethane grout. Its ability to penetrate narrow cracks and react with water creates a durable, flexible seal. The product’s flow characteristics made it ideal for tight joints, and its expansive properties ensured comprehensive coverage within the voids and cracks. The injection plan called for drilling at the locations marked on the provided site photos, angling back toward the metal at approximately 18 inches deep to intersect the leak path.

Procedures

1. Identified injection points along the crack, using red-dot markings on the structure as a guide.
2. Drilled holes at 45° angle 12-inches apart, reaching approximately 18 inches deep to intersect the metal interface.
3. Injected Spetec PUR F400 polyurethane grout through the drilled ports, using a pump setup suitable for low-viscosity materials.
4. Monitored for material refusal and evidence of grout migration to ensure the joint was fully saturated and sealed.
5. Continued injection until the crack would not accept additional material, confirming a complete watertight barrier.

Results

The injection process successfully sealed the tunnel leak at the concrete-to-metal interface. The approach allowed for precise targeting of the leak path, with minimal disturbance to the tunnel structure and no need for extended closure or demolition. The client was able to resolve the water infiltration efficiently, reducing the risk of future deterioration and avoiding the significantly higher costs and downtime associated with traditional excavation or membrane replacement. This project demonstrates the effectiveness of modern polyurethane injection in addressing challenging below-grade leak scenarios, particularly where access is limited and the leak path is confined.

Want more information about sealing cracks with polyurethane?

 

In the realm of leak seal solutions, selecting the right equipment is crucial for the effective application of grouts. The SealMaster gun, developed by Alchatek, is designed specifically for crack injection and curtain grouting tasks. This tool facilitates controlled delivery of materials into cracks and voids, ensuring thorough penetration and sealing in concrete structures. Ideal for professionals in advanced leak seal operations, the SealMaster gun combines functionality with user-friendly features to support an efficient workflow on-site.

Features

• Built-in pressure gauge.
• Extended whip hose.
• Simple design.

Benefits

• Monitor back pressure.
• Low maintenance.
• Easy port connection and disconnection.

The SealMaster adjustable flow gun stands out as a reliable choice for contractors focused on leak seal applications, offering simplicity and precision that minimize downtime and enhance project outcomes.

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A multi-level parking facility in downtown Los Angeles was experiencing significant water infiltration through its concrete ceiling. Building management had noticed increasing water staining and active leakage, particularly following rain events. The water migration around electrical conduits and light fixtures was most concerning, creating potential safety hazards with the electrical systems. Previous attempts to seal the ceiling using conventional surface treatments had failed to resolve the issue. With the structure serving high-end retail clients, the property management company required a solution to effectively stop the leaks while minimizing disruption to the facility's daily operations.

Initial Assessment

Inspection revealed that water was infiltrating through microscopic pathways in the concrete, with particularly noticeable intrusion around embedded conduits and penetrations. Engineers determined that concrete shrinkage had created tiny void spaces around these penetrations, some measuring only thousandths of an inch. Water was following these pathways, traveling along the outside of conduits and emerging at light fixtures and junction boxes installed in the ceiling. The ceiling showed distinctive water staining patterns radiating from these fixtures, confirming the migration pathway. Traditional polyurethane grouts would be too viscous to effectively penetrate these extremely small void spaces, requiring a material with exceptional flow characteristics.

Proposed Solution

Alchatek recommended using a specialized acrylic resin, Spetec AG 200. This material was selected specifically because of its extraordinarily low viscosity, significantly thinner than polyurethane alternatives, allowing it to travel through microfractures and voids that water could penetrate. Unlike thicker injection materials, acrylic resin can follow the same migration pathways as water, creating a waterproof barrier precisely where needed. The material's ability to travel long distances from injection points would minimize the number of injection ports required, reducing ceiling penetrations while ensuring complete sealing coverage around electrical conduits and other vulnerable areas.

Procedures

1. Technicians identified and mapped all water intrusion points in the ceiling, identifying migration patterns to determine optimal injection locations.
2. Strategic drilling and port installation were performed at intervals designed to intercept the water pathways, with particular focus on areas around electrical conduits.
3. Ports were installed in a pattern that would allow the low-viscosity material to flow along the same paths as the water infiltration.
4. Acrylic resin was injected through the ports, with continuous monitoring for material appearance at distant locations.
5. Injection continued at each port until the material was observed emerging from adjacent ports or known leak points, confirming pathway filling.
6. Engineers carefully monitored electrical systems throughout the process to ensure no disruption to the building's operations.

Results

The injection program successfully sealed the water infiltration pathways throughout the parking structure ceiling. Post-treatment monitoring through several significant rain events confirmed that all previously active leaks had been eliminated, with no further water migration observed around electrical fixtures. Most importantly, the acrylic resin's exceptional flow characteristics allowed for complete sealing with minimal disruption to the facility's operation. The property management company avoided spending an estimated $80,000-$100,000 that more invasive remediation methods would have required, while eliminating potential liability from water contact with electrical systems. The parking facility remained operational throughout the repair process, avoiding revenue loss that would have resulted from traditional ceiling replacement or excavation of the deck above.

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The property manager for a multi-level parking garage contacted Pavecon regarding persistent water infiltration in an elevator pit. The facility engaged Allana Buick & Bers, Inc. to develop a remediation strategy. Water leakage in elevator pits poses risks to equipment, safety, and can lead to service disruptions.

Initial Assessment

Inspection revealed multiple water entry points in the concrete walls of the elevator pit. The recurring water infiltration threatened the elevator system's integrity and created potential safety issues. Traditional repair methods would require extensive excavation and significantly disrupt parking facility operations, making them impractical and costly. The assessment determined that an effective solution was needed to address active leaks and provide long-term waterproofing without frequent maintenance.

Proposed Solution

The team selected a specialized polyurethane injection system (Spetec PUR F400) for the elevator pit leakage. This product effectively seals active water leaks in concrete structures by creating a waterproof barrier without extensive excavation. The method required only brief elevator shutdown periods rather than extended facility closures and could be applied even with active water infiltration.

Procedures

1. Thoroughly cleaned repair areas to remove dirt, debris, and loose concrete that could compromise adhesion.
2. Drilled through the concrete wall at strategic locations to access water infiltration pathways.
3. Installed injection ports (zerk fittings) into each drilled hole to facilitate polymer application.
4. Injected water when necessary to properly activate the polyurethane foam reaction.
5. Polyurethane injection material was applied through installed ports, allowing it to expand and fill voids.
6. Performed sequential injection following a pattern to ensure complete coverage of affected areas.
7. Removed injection ports and patched drill holes with hydraulic cement after the injection process.
8. Performed final inspection to verify cessation of all leaks.

Results

The polyurethane injection process successfully sealed all water infiltration points in the elevator pit, creating a waterproof barrier. The repair was completed within the scheduled timeframe, minimizing elevator system downtime. The project addressed approximately 17 linear feet of repair work.

After several substantial rain events, the elevator pit remained completely dry, confirming the solution's effectiveness. The property manager expressed satisfaction with the results, subsequently requesting additional services at other facilities and providing positive recommendations.

This solution demonstrated significant cost advantages over traditional methods, saving an estimated 60-70% compared to conventional waterproofing approaches while preventing potential damage to electrical and mechanical components.

Want more information on leak seal material and equipment?

Concrete leak repair is crucial for homeowners with leaks in basements or other below-grade spaces. Concrete can deteriorate over time due to imperfect construction, weather, wear, and unstable soil. However, effective solutions are available. This article explains how polyurethane leak seal grouts offer a cost-effective, durable fix for waterproofing your home.

The Problem with Standard Concrete Leak Repair Methods

Many homeowners initially try using sump pumps or hydraulic cement to remedy leaks. While these may provide a band-aid, they don't get to the root of the problem. Sump pumps only remove leaking water after it has already infiltrated. Hydraulic cement may temporarily stop the leak, but it is a rigid negative side bandied and thus prone to cracking as a structure shifts and settles.

The Benefits of Polyurethane Concrete Leak Repair

In contrast, experienced leak seal specialists rely on polyurethane grouts to stop leaks at their source. They inject this material into leaking cracks and joints. The grouts then react with water to form a flexible, watertight seal. Even as a structure naturally moves, the seal stays intact. Furthermore, polyurethane grouts provide industrial-grade strength while remaining safe for residential use.

The Importance of Professional Application

While injecting polyurethane grouts may sound simple, skilled professionals should handle it. Contractors undergo training to properly drill injection holes, prepare the components, and apply the product for maximum effectiveness. An expert will ensure the grout fully penetrates the leaks and forms a reliable, long-term seal.

Environmentally-Friendly Leak Repair

When selecting a contractor, look for one that uses NSF/ANSI/CAN 61 certified products. For example, most of Alchatek's leak seal grouts are NSF-certified to meet strict environmental standards. NSF certification involves both initial and ongoing testing, so you can trust these products always to be eco-friendly.

Key Takeaways

Concrete leak repair doesn't have to be a daunting task. Armed with the right products and expertise, a skilled contractor can provide an effective, long-lasting solution. When you choose a professional specializing in polyurethane leak seal grouts, you'll gain an ally in protecting your home against water intrusion.

Fill out this form or call 404-618-0438 for a contractor referral today!

Want more information on polyurethane concrete leak repair?

Construction and building maintenance rely on effective waterproofing to ensure longevity and structural integrity. In fact, waterproofing protects against water damage and moisture-related structural issues in residential homes, commercial buildings, and infrastructure projects. Positive side waterproofing and negative side waterproofing are two different methods that are used based on factors like construction design, budget, and water exposure.

Positive Side Waterproofing

Positive side waterproofing applies the material to the exterior or positive side of the building structure—the side exposed to the elements and potential water ingress. As a result, this method creates an outer surface barrier that prevents water penetration. Positive side waterproofing offers several advantages. Firstly, it provides effective protection by preventing water intrusion from entering the structure, as the externally applied material acts as a barrier. Secondly, water pressure actually assists in the process by pushing the cured material against the building, which helps to maintain a watertight seal. Finally, since the waterproofing layer is applied externally, it allows for various aesthetic finishes to be applied on the interior surface without compromising the functionality of the waterproofing system.

Negative Side Waterproofing

On the other hand, negative side waterproofing treats the interior surfaces of the building. Consequently, this method prevents water infiltration from the inside surface. While negative side waterproofing can be more cost-effective in the short term, it comes with several disadvantages. One major drawback is the limited protection it provides, as it does not protect against external water pressure. Additionally, negative side waterproofing fails to prevent the corrosion of reinforcing steel, as water can still reach it. Interior waterproofing may also impact the design and finishing of interior spaces. Furthermore, water pressure constantly pushes waterproofing material away from the surface, significantly reducing its service life compared to positive side waterproofing.

Choosing the Right Method

Various factors, including building design, site conditions, budget, and water exposure influence the choice between the positive side and negative side waterproofing. Additionally, it's important to understand that chemical grouting allows for positive side waterproofing application from the negative side without excavation. The decision should be based on a thorough assessment of the building's needs in consultation with an experienced contractor. 

Fill out this form or call 404-618-0438 for a contractor referral today!

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Are you dealing with a damp basement due to leaking walls? Water seeping into your below-grade rooms can ruin living spaces, destroy stored items, and lead to mold growth. However, you can stop this problem by hiring a contractor trained in sealing concrete cracks.

What Causes Concrete Wall Cracks?

Several factors can cause basement wall cracks that allow water intrusion:

• Imperfect construction: New homes often develop leaks if builders don't properly waterproof them
• Aging concrete: Exposure to hot/cold cycles and general aging creates cracks over time
• Unstable soil: Soil issues like erosion, poor compaction, and freeze/thaw cycles undermine foundations

While temporary surface repairs exist, polyurethane injection from the inside provides the best long-term solution. Depending on your situation, trained waterproofing contractors will likely use one of two methods.

Option 1 - Polyurethane Crack Injection

Polyurethane crack injection offers several advantages. Depending on the structure, contractors may be able to do it from either side of the wall, allowing the space to remain in use during repair. Additionally, the polyurethane material reacts with the leaking water to cure into a flexible seal (allowing for slight structural movement over time).

The Crack Injection Process

1. Locate and prepare the crack surface
2. Drill injection holes along the crack at an angle
3. Flush the holes with water to remove debris
4. Install injection ports and inject water to confirm the flow direction
5. Inject polyurethane grout, normally starting at the lowest point
6. Reinject grout a second time
7. Inject a final round of water to reactivate any remaining grout

Contractors need about 1 gallon of grout per 25 linear feet of cracks. Although this process is straightforward, it's not a DIY or handyman project. Always consult a professional to ensure they use proper techniques and materials.

Option 2 - Polyurethane Curtain Wall Grouting

Curtain wall grouting involves injecting an entire wall or section with polyurethane to create a waterproof barrier. This method is ideal when a wall has numerous cracks that are difficult to locate and inject individually.

The Curtain Wall Grouting Process

1. Drill a diamond-shaped grid of injection holes across the wall
2. Beginning at the bottom, inject each hole with polyurethane grout
3. Work up the wall, with each new row of grout flowing over the previous
4. Continue until the entire area is sealed

The injected grout penetrates into the soil behind the wall, forming a water-impermeable curtain. Consequently, this "positive side" waterproofing stops the water at its source. As a result, it blocks any seepage from entering the wall.

Contractors pioneered this technique in the 1960s for leaking manholes, and it's effective on concrete, block, stone, brick, and even wood or metal. They often use it for basements with hard-to-find cracks, previously failed injections, or masonry walls unsuitable for individual crack injection.

The specific polyurethane grout used for a curtain wall depends on soil conditions, voids, and water volumes. Therefore, always consult with a waterproofing professional so they can choose the ideal grout and injection pattern.

Hiring a Professional Trained in Sealing Concrete Cracks

Both polyurethane crack injection and curtain wall grouting are highly effective when trained experts do them properly. With either approach, the injected grout creates a permanent, flexible water barrier that reacts with the leaking water.

Once professionals permanently seal the leaks, you can confidently use your below-grade room without worrying about future water damage. As a result, you'll enjoy your dry, comfortable space for decades to come!

Fill out this form or call 404-618-0438 for a contractor referral today!

Want more information about crack injection and curtain wall grouting?

Essential Details

Dates/Pricing

Slab Lifting Masterclass: April 15th & 16th, 2024 – $685.00
Public Works Infrastructure Repair: April 18th & 19th, 2024 – $685.00

Location

Spray Foam Systems
1502 Airport Rd.
Greensboro, GA 30642
Click Here for Directions

Discount

Register for both classes and get a 25% discount

Slab Lifting Masterclass: April 15th & 16th, 2024 – $685.00

The concrete lifting master is an intensive opportunity to learn what it takes to start a concrete lifting business and then take it to the next level. The training you will receive will include Safety, Site Evaluation, Estimating, Product Selection, Sales, Equipment, Concrete Lifting Techniques, and Deep Lift / Deep Lock. You will also learn about taking your concrete lifting business to the next level. You will learn about other tools we have to help you land bigger jobs and how to engage the engineering community to gain access to unique markets. Join the industry’s top team of concrete lifting professionals for training, learning, and fun.

Public Works: April 18th & 19th, 2024 – $685.00

The public works course is two days dedicated to training and teaching Public Works professionals and specialty grouting contractors. You will learn how to utilize polyurethane technology to solve problems that municipalities and public works departments commonly face and how to do it at a fraction of the cost of traditional methods. There will be a heavy emphasis on sealing underground infrastructure and stabilizing and lifting roads. We will cover the full spectrum of our product line including Leak Seal, Permeation, Soil Stabilization, and Slab Lifting. Join the industry’s top team of infrastructure specialists for training, learning, and fun.

Essential Details

Dates/Pricing

Slab Lifting Masterclass: April 15th & 16th, 2024 – $685.00
Public Works Infrastructure Repair: April 18th & 19th, 2024 – $685.00

Location

Spray Foam Systems
1502 Airport Rd.
Greensboro, GA 30642
Click Here for Directions

Discount

Register for both classes and get a 25% discount

Slab Lifting Masterclass: April 15th & 16th, 2024 – $685.00

The concrete lifting master is an intensive opportunity to learn what it takes to start a concrete lifting business and then take it to the next level. The training you will receive will include Safety, Site Evaluation, Estimating, Product Selection, Sales, Equipment, Concrete Lifting Techniques, and Deep Lift / Deep Lock. You will also learn about taking your concrete lifting business to the next level. You will learn about other tools we have to help you land bigger jobs and how to engage the engineering community to gain access to unique markets. Join the industry’s top team of concrete lifting professionals for training, learning, and fun.

Public Works: April 18th & 19th, 2024 – $685.00

The public works course is two days dedicated to training and teaching Public Works professionals and specialty grouting contractors. You will learn how to utilize polyurethane technology to solve problems that municipalities and public works departments commonly face and how to do it at a fraction of the cost of traditional methods. There will be a heavy emphasis on sealing underground infrastructure and stabilizing and lifting roads. We will cover the full spectrum of our product line including Leak Seal, Permeation, Soil Stabilization, and Slab Lifting. Join the industry’s top team of infrastructure specialists for training, learning, and fun.

After identifying tunnel leaks, the next step is exploring sealing methods. While crack/joint injection and curtain grouting are common solutions, they are not one-size-fits-all. By understanding the range of options and their pros and cons, engineers, maintenance teams, and infrastructure managers can make informed decisions tailored to each leak's unique circumstances. 

Crack/Joint Injection and Curtain Grouting: A Brief Overview

Before diving into alternative methods, let's briefly touch upon the two most commonly used techniques for sealing tunnel leaks.

Crack/Joint Injection

Crack/joint injection involves injecting a sealing material, often a polyurethane grout, directly into the cracks or joints where water is leaking. This method is highly effective for sealing small, accessible leaks and is often used in concrete tunnels.

Curtain Grouting

Curtain grouting involves injecting grout in a curtain-like pattern behind the tunnel lining to create a waterproof barrier. This method is more suitable for larger leaks or when the exact location of the leak is unknown.

Alternative Methods

While crack/joint injection and curtain grouting are effective, they are not always the best fit for every situation. Here are some alternative methods worth considering:

Mechanical Seals

Mechanical seals use physical components like gaskets, O-rings, or metal clamps to seal off leaks. These are often used in utility tunnels where pipes or cables pass through the tunnel walls.

Cementitious Grouts

Cementitious grouts are water-based grouts that can be used in wet environments. They are often used in combination with other methods to provide a more robust sealing solution.

Epoxy Resins

Epoxy resins are synthetic materials that can adhere to a variety of surfaces. They are particularly useful for sealing leaks in metal tunnels or in areas where a strong bond is required.

Swellable Waterstops

These are hydrophilic materials that expand upon contact with water, effectively sealing off leaks. They are often used in construction joints and are particularly effective in concrete tunnels.

Factors Influencing Method Selection

Choosing the right tunnel sealing method involves considering several factors:

Material Compatibility

The material of the tunnel lining plays a significant role in method selection. For example, cementitious grouts work well with concrete surfaces, while epoxy resins are more suitable for metal surfaces.

Severity and Location of the Leak

The size and accessibility of the leak also influence the choice of method. Crack/joint injection is more suitable for small, accessible leaks, while curtain grouting or mechanical seals might be better for larger or less accessible leaks.

Environmental Considerations

The surrounding environment can also influence method selection. For example, in tunnels close to natural water bodies, it's crucial to choose environmentally friendly sealing materials.

Criteria for Selecting a Tunnel Sealing Method

When choosing a sealing method, stakeholders should consider the following criteria:

Effectiveness

The primary consideration should be the method's effectiveness in sealing the leak and preventing future leaks.

Cost-Efficiency

While it's tempting to opt for the cheapest solution, stakeholders should consider the long-term costs, including maintenance and the potential need for resealing.

Regulatory Compliance

Different jurisdictions have varying regulations concerning tunnel maintenance and repair. It's crucial to choose a method that complies with these regulations to avoid legal complications.

Long-Term Sustainability

The chosen method should offer a durable solution that stands the test of time, minimizing the need for frequent repairs.

Key Takeaways

Sealing methods for tunnel leaks go beyond just crack/joint injection and curtain grouting. Various factors, including material compatibility, leak severity, and environmental considerations, influence the choice of method. By understanding these factors and criteria, stakeholders can make informed decisions that not only address the immediate issue but also offer long-term benefits.

For more information on sealing leaks with polyurethane grout...