PU (polyurethane) high-pressure injection grouting is one of the most effective ways to stop active water leaks in concrete. KL Servis Rumah uses this method to seal leaking walls, slabs, basements, and car parks across Kuala Lumpur and Selangor, from RM 300 per point.
This guide explains what PU grouting is, when it is used, and what to expect from the process.
What Is PU Injection Grouting?
It is a waterproofing method where a special polyurethane resin is injected into a crack, joint, or honeycomb void in concrete under high pressure. The resin reacts with water, expands, and fills the gap — sealing the leak from the inside.
It is different from surface coating: instead of covering the outside, it stops water at the point it enters.
When Is PU Grouting Used?
- Active cracks in concrete walls — where water is actively leaking through.
- Slab and basement leaks — water rising through concrete floors.
- Joint leaks — where two concrete sections meet.
- Car park and podium leaks — water seeping through concrete.
- Retaining walls — where water pressure pushes through.
The Grouting Process
- Locate the leak — we identify the crack or point of water entry.
- Drill injection holes — small holes are drilled along the crack.
- Inject the resin — PU resin is injected under high pressure.
- The resin expands — it reacts with water and fills the crack.
- Finish the surface — the injection points are patched and sealed.
Advantages Over Surface Coating
- Stops active leaks — works even where water is flowing.
- Seals from the inside — water pressure pushes the seal tighter.
- Minimal surface damage — small injection holes only.
- Durable — the expanded resin remains flexible and watertight.
How Much Does PU Grouting Cost?
PU injection grouting starts from RM 300 per point. The final cost depends on:
- The number and length of cracks
- The depth and condition of the concrete
- Access to the affected area
- Whether finishing (repairing injection points) is included
You receive a fixed quote after inspection.
Frequently Asked Questions
Is PU grouting better than a waterproofing coating?
For active leaks through cracks, injection grouting is usually more effective because it seals from inside the concrete. Surface coatings work best for preventing water on new or dry surfaces.
Does PU grouting require breaking the wall?
No. Only small injection holes are drilled, so there is minimal surface damage compared to excavating the leak.
How long does the grouting last?
Properly injected PU resin is durable and remains flexible, so it provides a long-lasting watertight seal. It is a permanent solution for the injected area.
Can PU grouting fix a leaking bathroom?
In many cases, yes — if the leak is through a crack or joint in the concrete, injection grouting can stop it without removing tiles. The best method depends on the source of the leak.
Get PU Grouting Help
If water is actively leaking through a concrete wall, slab, or basement, PU high-pressure injection grouting can stop it efficiently. KL Servis Rumah provides this service across Kuala Lumpur and Selangor. WhatsApp us for a free assessment — chat with our team.