Family-owned and operated since 2000, Complete Basement Systems (CBS) is proud to be Long Island’s longest-standing basement and crawl space repair company. For more than 25 years, we’ve helped homeowners protect their most valuable investment by preventing water and humidity damage. Our consultative approach sets us apart—we don’t just fix problems, we educate homeowners and deliver tailored solutions designed for lasting peace of mind.
Founded in 1984, PTS Foundation Supply (PTSFS) has been the Northeast’s go-to resource for helical piles, driven anchors, and installation equipment. From design to installation, we know how complex foundation projects can be. That’s why professionals across the region count on our 100+ years of collective experience to provide reliable products, expert insight, and a partnership that helps every project start—and finish—on solid ground.
Since 1973, Premium Technical Services (PTS) has been the Tri-State area’s trusted partner in foundation repair, below-grade waterproofing, and grouting. With more than 50 years of service and over 100 years of combined expertise on our team, we bring proven solutions to keep your foundation strong, dry, and secure for the long run.
Family-owned and operated since 2000, Complete Basement Systems (CBS) is proud to be Long Island’s longest-standing basement and crawl space repair company. For more than 25 years, we’ve helped homeowners protect their most valuable investment by preventing water and humidity damage. Our consultative approach sets us apart—we don’t just fix problems, we educate homeowners and deliver tailored solutions designed for lasting peace of mind.
Founded in 1984, PTS Foundation Supply (PTSFS) has been the Northeast’s go-to resource for helical piles, driven anchors, and installation equipment. From design to installation, we know how complex foundation projects can be. That’s why professionals across the region count on our 100+ years of collective experience to provide reliable products, expert insight, and a partnership that helps every project start—and finish—on solid ground.
Urethane Injection Crack Repair for Waterproofing & Flexibility
"*" indicates required fields
It’s essential to have a permanent and flexible seal if water finds its way through your foundation. Urethane injection crack repair, also known as polyurethane crack repair waterproofing, is one of the most effective foundation crack repair services for stopping active leaks and protecting against future water intrusion. Unlike rigid materials such as hydraulic cement or epoxy, polyurethane foam expands and flexes with natural foundation movement, sealing even the smallest voids to keep basements dry year-round.
At Complete Basement Systems, homeowners across Long Island trust our team for residential and local urethane injection crack repair solutions that deliver fast, reliable results without major disruption. Meanwhile, Premium Technical Services provides engineered polyurethane crack repair waterproofing for large-scale commercial structures across NYC and surrounding areas, ensuring watertight protection and long-term flexibility in high-performance environments.
Urethane injection complements our epoxy-focused offerings, providing the ideal waterproofing solution for non-structural and actively leaking cracks. Whether you’re a homeowner dealing with seepage or a contractor seeking dependable foundation crack repair services, our experts will help you select the right method.
What Is Urethane / Polyurethane Injection?
Urethane injection crack repair is a waterproofing method that uses a moisture-reactive, expanding foam to seal leaking foundation cracks from the inside out. During the process, technicians install injection ports along the visible crack, allowing a low-viscosity sealant to be injected deep into the concrete using specialized tools and controlled pressure. Once the urethane resin comes into contact with moisture, it reacts and expands into a flexible foam that completely fills the crack, stopping active leaks and preventing future water intrusion.
There are two main types of polyurethane materials used in this process: hydrophobic and hydrophilic. Hydrophobic urethane repels water, making it ideal for wide or continuously leaking cracks, while hydrophilic urethane reacts and mixes with water to create a durable, watertight bond in damp or saturated concrete. Together, these moisture-sensitive formulations make urethane injection crack repair one of the most versatile and effective methods for permanent basement waterproofing.
How Urethane Injection Works
At a high level, urethane injection crack repair drives a moisture-reactive resin into leaking cracks in concrete, where it reacts and expands into polyurethane foam to form a flexible, watertight seal. Technicians install low-profile ports and use specialized tools to push the material through the crack plane inside the wall, allowing the foam to chase water pathways and fill voids that traditional patching can’t reach. The result is a durable, elastic barrier that keeps water out while accommodating minor movement in the substrate.
This approach scales from a contractor-grade pump setup to a homeowner-friendly kit, making it suitable for everything from damp hairline fissures to actively leaking joints. Because the foam expands on contact with moisture, it’s especially effective for non-structural leaks where stopping water is the primary goal.
When to Use Urethane - Use Cases & Decision Criteria
Urethane injection crack repair is the preferred process for addressing water intrusion through foundation cracks that are actively leaking, damp, or subject to movement. Because urethane reacts with moisture and expands to form a flexible, watertight barrier, it’s ideal for sealing cracks that can’t stay dry long enough for other materials, like epoxy, to bond properly.
This method is most effective for non-structural cracks where the goal is waterproofing rather than structural reinforcement. Common scenarios include hairline cracks in poured concrete walls, floor joints, or cold seams where water seeps through. Once injected, the urethane foam fills the entire crack path, sealing off leaks from the inside and preventing further moisture infiltration.
If structural strength is a concern, an epoxy injection may be used instead of or alongside urethane for a dual solution.
Advantages/Benefits of Urethane Injection
Urethane injection crack repair offers several key advantages for homeowners and contractors seeking lasting waterproofing and flexibility. This method creates a reliable seal that adapts to movement, moisture, and changing conditions, something rigid materials can’t match.
- Waterproof performance: Expanding polyurethane foam fills the entire crack and creates a watertight barrier against leaks and seepage.
- Moisture tolerance: Unlike other repair materials, urethane actually reacts with water, making it ideal for damp or actively leaking cracks.
- Flexibility under movement: The cured foam stays elastic, allowing the repair to flex with natural foundation shifts without reopening.
- Fast cure times: Repairs are often set within minutes, minimizing downtime and disruption.
- Permanent protection: Once cured, urethane injection crack repair forms a permanent waterproof seal that prevents future water intrusion.
- Minimal structural disruption: In most cases, cracks can be repaired from the interior, with no excavation or exterior access required.
- Versatile application: Effective for both residential and commercial projects, from hairline wall leaks to large-scale waterproofing.
Advantages/Benefits of Urethane Injection
Urethane injection crack repair offers several key advantages for homeowners and contractors seeking lasting waterproofing and flexibility. This method creates a reliable seal that adapts to movement, moisture, and changing conditions, something rigid materials can’t match.
- Waterproof performance: Expanding polyurethane foam fills the entire crack and creates a watertight barrier against leaks and seepage.
- Moisture tolerance: Unlike other repair materials, urethane actually reacts with water, making it ideal for damp or actively leaking cracks.
- Flexibility under movement: The cured foam stays elastic, allowing the repair to flex with natural foundation shifts without reopening.
- Fast cure times: Repairs are often set within minutes, minimizing downtime and disruption.
- Permanent protection: Once cured, urethane injection crack repair forms a permanent waterproof seal that prevents future water intrusion.
- Minimal structural disruption: In most cases, cracks can be repaired from the interior, with no excavation or exterior access required.
- Versatile application: Effective for both residential and commercial projects, from hairline wall leaks to large-scale waterproofing.
Limitations/Risks of Urethane Injection
While urethane injection crack repair is an excellent solution for waterproofing and flexibility, it does have some limitations that should be considered before selecting this method.
- Not for structural reinforcement: Urethane is designed for waterproofing, not for restoring strength. Epoxy is a better option for structural repairs.
- Foam shrinkage potential: If the moisture balance isn’t correct, the expanding foam can occasionally retract or shrink over time.
- Requires proper activation: Successful results depend on precise control of pressure and moisture during the injection process.
- Risk of incomplete fill: Without adequate drilling or port placement, the foam may not fully penetrate deep or hidden crack paths.
- Temperature sensitivity: Very low temperatures can slow reaction and curing times.
- Limited re-entry: Once urethane injection crack repair is completed, re-injecting or adjusting the repair later can be difficult.
- Surface preparation matters: Contaminants or poor access can reduce bond strength and sealing performance.
Step-by-Step: Urethane Crack Repair Process
The urethane injection crack repair method follows a systematic approach to ensure full penetration, expansion, and sealing of every crack. Here’s an overview of how professionals perform this reliable waterproofing process.
1. Inspection & Evaluation
Technicians begin by inspecting the crack’s length, width, and moisture level to determine if urethane injection crack repair is the best solution. Active leaks, damp areas, and non-structural foundation cracks are ideal candidates for this flexible waterproofing approach.
2. Port Installation & Crack Flushing
Low-profile injection ports are installed along the crack at set intervals, ensuring access points for the sealant. The area is then flushed to remove dirt, debris, and standing water, creating a clean path for the resin to travel once injected.
3. Injection Sequence
Using specialized equipment, technicians inject a moisture-reactive resin under controlled pressure. As it comes into contact with water, the material expands into polyurethane foam, filling voids and creating a watertight seal from deep within the concrete.
4. Curing & Verification
Once the polyurethane foam has fully expanded and cured, the ports are removed and the surface is sealed. A follow-up inspection ensures the crack is completely filled and the repair is performing as intended.
Technical Considerations & Best Practices
Achieving long-lasting results with urethane injection crack repair requires careful control of materials, pressure, and moisture throughout the process.
- Pressure ranges: Maintain steady, moderate injection pressure to ensure the resin travels through the entire crack without causing blowouts or bypassing narrow sections.
- Foam expansion control: Monitor reaction rates closely. Too much expansion can create internal stress, while too little may leave gaps or weak spots.
- Moisture activation parameters: Since urethane reacts with water, managing the correct moisture content is essential for complete activation and uniform expansion.
- Avoiding incomplete fill or voids: Proper port spacing, sequential injection, and consistent flow are critical to prevent unsealed areas within the crack path.
- Quality assurance: Documenting pressure readings and foam behavior during each urethane injection crack repair helps verify performance and prevent rework.
Epoxy Injection Crack Repair FAQs
No. Urethane injection crack repair is designed for waterproofing, not structural reinforcement. It seals leaking cracks with flexible polyurethane foam, while epoxy injection is used when strength restoration is required.
When properly installed, polyurethane foam can last for decades. It remains flexible and watertight, even as the foundation naturally shifts over time.
Yes, though failures are rare when the process is done correctly.
Yes. In fact, urethane is ideal for wet environments since the polyurethane foam reacts with moisture. However, very cold temperatures may slow the curing process and require adjusted techniques.
The reaction is fast. Polyurethane foam typically expands and cures within minutes, allowing for quick waterproofing and minimal disruption.
DIY urethane injection crack repair kits exist for small residential cracks, but professional installation ensures the best results, especially for larger or active leaks where experience and proper equipment make a difference.
Give Premium Technical Services a Call Today
Whether you’re dealing with active leaks or damp foundation walls, urethane injection crack repair offers a proven solution for long-lasting waterproofing and flexibility. The experts at Premium Technical Services provide both residential and commercial injection services throughout NYC and surrounding areas, plus full epoxy crack repair options for structural reinforcement when needed.
If you’re ready to stop leaks and protect your property, give us a call today at (516) 409-6000 or fill out our online form to schedule a consultation. Explore our case studies to see how our team has helped homeowners, contractors, and building managers achieve permanent waterproofing results with professional urethane injection crack repair and epoxy injection solutions.