What is polyurethane injection?
Polyurethane injection introduces a water-reactive or flexible resin into leakage paths to control water ingress through cracks, joints and voids.
What it solves
It is commonly used for active water-bearing cracks or joints when the repair objective is water control rather than structural bonding.
When it may not be suitable
PU injection does not by itself restore structural continuity. Water source, crack movement, hydrostatic pressure, access and durability expectations must be assessed before selecting the resin and injection sequence.
Typical applications
- Basements and retaining walls
- Tunnels and below-grade spaces
- Water-retaining structures
- Construction joints and penetrations
Execution workflow
- Review assessment and design basis
- Confirm method, access and compatible system
- Prepare substrate and control the work area
- Install or apply under documented procedure
- Inspect, record and hand over
Materials and systems
Typical systems include hydrophilic or hydrophobic polyurethane resins, catalysts where applicable, mechanical packers and compatible surface-sealing products.
Product families are selected generically at planning stage and specified only after compatibility, performance requirements and site conditions are confirmed.
Quality control approach
Controls are matched to the intervention and may include substrate acceptance, batch and shelf-life checks, mixing records, temperature and moisture readings, installation sequencing, pull-off or proof testing where specified, photographic records and signed inspection points.
Limitations and engineering considerations
What we need before we recommend this method
A photograph can help start the conversation, but it cannot establish a structural diagnosis on its own. Useful inputs include:
- Photographs showing the wider structure and the defect
- Available drawings, reports or previous repair records
- Crack, leakage or deterioration history
- Known movement, loading or change-of-use information
- Access, occupancy and shutdown constraints
- Available substrate tests or condition data
Frequently asked questions
It is commonly used for active water-bearing cracks or joints when the repair objective is water control rather than structural bonding.
No. Suitability depends on verified condition, engineering requirements, substrate, exposure, access and the intended service life. Project-specific assessment and design may be required.
The project method should define substrate acceptance, material checks, environmental limits, installation records, hold points, inspection and handover documentation appropriate to the system.