Water is coming through a basement wall.
A construction joint is dripping continuously.
There is an active leak through a concrete crack, and applying another coating over the surface is not stopping it.
At this stage, the usual question is:
“Which waterproofing chemical should we apply?”
But when water is actively moving through a crack or joint, a surface-applied waterproofing material may not be the first treatment required.
This is where PU injection grouting can become relevant.
Polyurethane injection grout is injected into cracks, joints or voids inside concrete so that the material reaches the leakage path rather than only covering the visible surface.
But there is an important point:
PU injection is a specialised leakage-control method. It is not a universal solution for every crack, damp wall or waterproofing problem.
At ADT Industries, the correct approach begins by understanding where the water is entering, whether the crack is carrying active water, what type of concrete defect is present, and whether the problem requires leakage sealing, structural repair or both.
What Is PU Injection Grouting?
PU injection grouting is a method of injecting polyurethane resin into cracks, construction joints, voids or water-bearing pathways in concrete.
For active-leak applications, certain PU systems react with moisture and expand or foam inside the leakage path.
The objective is to:
- penetrate the water-bearing crack or void
- react within the leakage pathway
- fill irregular spaces
- reduce or stop active water movement
- create a flexible seal within the concrete
Unlike simply coating the face of a leaking wall, injection attempts to reach the internal path through which water is travelling.
The visible wet patch is not always the actual entry point.
What Do We Mean by “Active Water Leakage”?
Active leakage means water is currently moving through the structure, rather than the area simply being damp from previous exposure.
Examples include:
- water dripping through a concrete crack
- continuous seepage through a construction joint
- water entering through a basement wall
- leakage appearing under hydrostatic pressure
- water flowing through a slab or wall penetration
- active seepage through an underground concrete structure
This is different from:
- an old dry crack
- surface dampness
- peeling paint
- condensation
- general wall porosity
- a plumbing leak
Those conditions may require completely different treatments.
When Should PU Injection Grouting Be Considered?
1. Active Leakage Through Concrete Cracks
One of the most common applications is a water-bearing crack in concrete.
When water is actively entering through the crack, an appropriate water-reactive PU injection grout can be injected through installed ports or packers.
The material travels into the crack and reacts within the leakage path.
This can be particularly useful where the water is coming from the negative side and the positive side of the structure is difficult to access.
The goal is to seal the path inside the concrete—not simply cover the wet surface.
2. Construction Joint Leakage
Construction joints are common leakage locations in:
- basements
- retaining walls
- water tanks
- podium structures
- underground structures
- lift pits
- tunnels
- RCC walls
A construction joint exists where one concrete pour meets another.
If joint detailing, waterstops or surrounding concrete are compromised, water may find a path through the joint.
Where water is actively travelling through such a joint, PU injection may form part of the repair strategy.
But the condition of the joint still needs to be assessed.
A leaking construction joint and a moving expansion joint are not automatically the same repair problem.
3. Basement Leakage
Basements are especially vulnerable because surrounding groundwater can exert pressure against below-ground walls and slabs.
Common leakage locations include:
- construction joints
- wall-floor junctions
- tie-rod holes
- concrete cracks
- pipe penetrations
- honeycombed areas
If water is actively entering through a defined crack or joint, PU injection can be considered after identifying the leakage path.
Basement leakage should be diagnosed by pathway—not simply by the location of the wet patch.
4. Retaining Walls and Underground Structures
Retaining walls and other below-grade structures can remain exposed to moisture and groundwater pressure for long periods.
Where access from the soil side is impossible, injection may allow treatment from the accessible side of the concrete.
PU injection systems are commonly considered where water is moving through:
- cracks
- cold joints
- construction joints
- localised voids
The complete repair may still require additional waterproofing, joint treatment or drainage correction depending on the cause.
5. Water-Bearing Voids and Porous Zones
Not every leakage path is a clean straight crack.
Water can sometimes pass through voids, honeycombed concrete or interconnected porous zones.
An injectable PU material may enter these irregular pathways more effectively than a surface repair material.
However, extensive honeycombing or concrete deterioration may also require concrete repair, not only injection.
Stopping water and restoring damaged concrete are two different jobs.
How Does PU Injection Grouting Work?
The exact method depends on the product, site condition and approved repair specification, but the general process usually follows a sequence.
Step 1: Identify the Leakage Path
Before drilling anything, determine:
- where water is entering
- the crack or joint direction
- whether leakage is active
- whether the concrete is sound
- whether the crack is moving
- whether reinforcement or structural distress is involved
This is the most important stage.
Injection should follow diagnosis—not guesswork.
Step 2: Mark the Injection Points
Injection locations are planned along the crack or joint.
The spacing, angle and depth depend on the geometry of the defect and the selected injection methodology.
The objective is to allow injected resin to reach and intersect the actual leakage pathway.
Step 3: Drill and Install Packers
Holes are drilled at suitable locations and injection packers are installed.
These packers allow the injection pump to deliver resin into the crack under controlled pressure.
Drilling position matters.
If the drill hole does not intersect the leakage path, the grout may not reach the required area.
Step 4: Inject the PU Resin
The PU grout is injected through the packers in a controlled sequence.
For suitable water-reactive systems, contact with moisture initiates a reaction that allows the material to expand and fill the available crack or void.
Injection generally progresses systematically so that the operator can observe how the material travels through the defect.
More pressure does not automatically mean a better repair.
Pressure needs to suit the concrete condition, crack geometry, equipment and selected material.
Step 5: Observe Leakage Reduction
As the injection material fills the pathway, active water movement should reduce.
Additional injection points may be required where the leakage path is irregular or interconnected.
Step 6: Complete the Surface Repair
Once the injection treatment is complete and the required curing has taken place, packers can be removed according to the approved method and drill holes repaired.
The surrounding surface may then require:
- crack finishing
- repair mortar
- protective coating
- waterproofing
- joint treatment
depending on the complete site condition.
Where ESSRBOND GS 500 Fits In
ADT Industries supplies ESSRBOND GS 500, a single-component, hydrophilic polyurethane injection grout intended for active crack sealing and leakage control.
The system is designed for applications where moisture is present within the leakage path and can be considered for locations such as:
- active concrete cracks
- construction joints
- basements
- retaining walls
- underground structures
- other water-bearing concrete defects
Because it is water-reactive, the product is intended to work within wet leakage conditions rather than requiring the leakage path to be completely dry.
However:
A suitable product does not replace correct diagnosis, drilling, packer placement and injection methodology.
The success of injection grouting depends on both the material and the application process.
PU Injection vs Epoxy Injection: They Are Not the Same
This distinction is extremely important.
People sometimes use “injection grout” as though every injection material performs the same function.
It does not.
PU Injection
PU injection is commonly used where water sealing and flexibility are important.
Depending on the PU chemistry, applications may include:
- active leakage
- wet cracks
- construction joints
- flexible sealing
- below-grade leakage paths
Epoxy Injection
Epoxy injection is generally associated with bonding and structural crack repair where the engineering objective is different.
ADT Industries also supplies Epoxy Injection Grout for appropriate structural crack-repair applications.
The simplified distinction is:
PU injection → primarily leakage sealing / flexible water control
Epoxy injection → primarily structural bonding of suitable cracks
But the actual product selection should always follow the site condition, structural requirement and manufacturer’s technical data sheet.
Do not select injection chemistry only because both products can be pumped into a crack.
When PU Injection Is NOT the Complete Solution
1. Structural Cracks Requiring Engineering Assessment
If a crack shows:
- significant movement
- displacement
- structural distress
- continuing widening
- reinforcement damage
simply stopping the water does not resolve the underlying structural condition.
A qualified structural professional should assess the member where appropriate.
2. General Wall Dampness
A wall that is broadly damp because of porous masonry or failed external waterproofing is not automatically a PU injection problem.
Injection treats defined leakage pathways.
General seepage may require a broader waterproofing strategy.
3. Plumbing Leakage
If the water source is a pipe, fitting or drainage line, injection grout does not replace plumbing repair.
4. Damaged Concrete
Where leakage has already contributed to concrete spalling, corrosion or loss of concrete cover, stopping the water may be only one stage of the rehabilitation.
The damaged concrete may require separate repair.
5. Poor Drainage or Continuous External Water Loading
If water is accumulating because of blocked drainage, defective slope or unresolved external waterproofing, injection may stop one leakage path while the underlying water-management problem remains.
Stopping one leak does not automatically waterproof the entire structure.
Common PU Injection Grouting Mistakes
Mistake 1: Injecting Without Finding the Real Leakage Path
Drilling directly into a wet mark without understanding how water is travelling can result in ineffective injection.
Mistake 2: Assuming Every Crack Needs PU
Dry structural cracks, moving joints, surface cracks and active water-bearing cracks may require different materials.
Mistake 3: Poor Packer Placement
Packers need to intersect the crack or leakage pathway properly.
Bad drilling geometry can prevent the grout from reaching the defect.
Mistake 4: Using Excessive Pressure
Uncontrolled injection pressure can be counterproductive and may affect weak concrete or force material into unintended locations.
Mistake 5: Stopping at the First Visible Reduction in Water
Leakage networks can be interconnected.
The entire affected path needs to be evaluated rather than treating only the first visible point.
Mistake 6: Ignoring the Condition Around the Crack
If surrounding concrete is honeycombed, spalled or structurally distressed, injection alone may not complete the repair.
Mistake 7: Skipping the Final Protection
After leakage control, the site may still require surface repair, joint treatment, waterproofing or protective coating.
PU injection can stop a leakage path. It does not automatically solve every surrounding waterproofing defect.
What Should You Check Before Choosing PU Injection?
Before deciding on the treatment, ask:
Is water actively flowing?
Is the leakage coming through concrete?
Is there a defined crack or joint?
Is the crack dry, damp or actively water-bearing?
Is the concrete around it sound?
Is the crack moving?
Is there reinforcement corrosion or spalling?
Can the positive side be accessed?
Has this location been injected before?
Is structural assessment required?
Those questions help determine whether injection is actually the correct methodology.
PU Injection Is a System, Not Just a Chemical
A successful injection job depends on:
Diagnosis → Correct injection material → Correct drilling pattern → Packer installation → Controlled injection → Leakage verification → Surface repair and protection where required
If any of these stages are ignored, simply choosing a premium PU grout does not guarantee a successful repair.
Injection grouting is as much about methodology as material.
How ADT Industries Approaches Active Leakage
At ADT Industries, an active leakage complaint should not begin with:
“Which chemical should we inject?”
It should begin with:
Where is the water entering?
Is it a crack, joint, penetration or porous zone?
Is the water actively flowing?
Is the crack structural or primarily a leakage pathway?
Is concrete deterioration also present?
What injection chemistry suits the condition?
What should happen after the injection is complete?
ADT Industries supplies PU injection grouts, epoxy injection systems, repair mortars, waterproofing materials, bonding systems and associated construction chemicals for leakage-control and repair applications.
Our role is not limited to supplying a product.
Customers can approach our team for product-selection and application guidance according to the actual site condition.
Because an active leak should be traced and treated from inside its pathway—not simply hidden at the surface.
A Final Thought Before Injecting a Leak
When water is flowing through concrete, the first reaction is often:
“Stop the water immediately.”
That is understandable.
But a better sequence is:
“Find the path. Understand the defect. Select the correct injection system. Then stop the water.”
PU injection grouting can be a highly useful technique for active water-bearing cracks and joints when the site condition is suitable.
But it should never become a one-product answer for every damp wall, crack or leakage complaint.
Diagnose the pathway. Select the correct chemistry. Inject correctly. Verify the result. Complete the surrounding repair.
That is how injection grouting becomes a repair method—not just an emergency reaction.
Need Help With an Active Water Leakage Problem?
If you are dealing with active concrete leakage, basement seepage, construction-joint leakage, water-bearing cracks or underground-structure leakage, speak with ADT Industries before selecting the injection material.
Our team can help you understand the application requirement and guide you towards the appropriate PU injection, epoxy injection, waterproofing or concrete-repair category for the site condition.
ADT Industries Pvt. Ltd.
Toll-Free: 1800 410 1818
Email: support@adtindustries.com
For structural cracks, significant movement, reinforcement damage or conditions that may affect structural safety, consult a qualified structural professional. Injection materials and application methods should follow the current manufacturer’s technical data sheet, approved repair methodology and actual site conditions.
