PU Grouting vs Full Membrane Waterproofing: How to Choose

Bathroom leaking downstairs? Balcony dripping into the unit below? You've probably heard two very different recommendations:

1. "PU grouting — no need to hack tiles, done in a day."
2. "Hack everything, redo the membrane, or the leak will return."

Both are right — for different situations. Here's how our waterproofing specialists at KL Servis Rumah decide.

When PU grouting is the right choice

PU (polyurethane) grouting injects a flexible chemical foam into cracks in the concrete slab, sealing the leak from below without touching your tiles.

Choose PU grouting when:

• You have a specific, traceable crack line in the slab.
• The bathroom above is otherwise in good condition (grout intact, membrane still bonded).
• You want a fast, non-destructive solution (2–4 hours, no tile damage).
• Budget is tight — PU is typically 60% cheaper than a full re-membrane.

Typical cost in KL: RM 650 to RM 2,500 for most bathroom slab leaks.

When full membrane redo is unavoidable

Choose full membrane replacement when:

• The whole membrane has failed — you can see damp patches on multiple walls below.
• The tiles or grout are already loose and need replacement anyway.
• The bathroom is 20+ years old and you're planning a refresh regardless.
• PU grouting has already been done more than once and keeps failing.

Typical cost in KL: RM 4,500 to RM 12,000 for a standard bathroom depending on tile grade and membrane spec.

The hybrid approach (our favourite)

For many mid-condition bathrooms, the smartest fix is a PU grout first + fresh grout re-seal + silicone touch-up — around RM 850 to RM 1,800 total.

If the leak returns in 12 months, you graduate to a full membrane at the next refresh — but often it doesn't.

4 mistakes to avoid

1. Skipping the ponding test — always confirm the leak path before choosing a method.
2. Painting over damp walls before waterproofing — the paint will peel within weeks.
3. Choosing the cheapest contractor — waterproofing failures are painful to redo.
4. Ignoring the source — no waterproofing fix works if you leave a broken pipe or blocked drain feeding the leak.

Warranty

Every KL Servis Rumah waterproofing job carries a written warranty:

• PU grouting: 12 to 36 months depending on scope.
• Acrylic membrane refresh: 24 to 60 months.
• Full membrane replacement: up to 60 months for professionally installed cementitious/PU membrane systems.

WhatsApp us the leak photo and the room layout — we'll advise which method fits before we send a technician.