Can I tile directly over CM200?

Yes. After 7 days full cure, CM200 is tile-ready. Use CM200 slurry as bond coat for tiles.

Does CM200 work on old bathroom walls already tiled?

For tiled surfaces, hack off existing tiles, prepare substrate, then apply CM200. Applying over existing tiles without hacking is not recommended.

How do I waterproof floor-wall junctions in bathrooms?

Apply an extra reinforcing coat of CM200 at junctions using a brush. These are the most vulnerable points — two additional coats at corners and joints.

Bathroom & Wet Area Waterproofing

The Problem: Why Bathroom Walls Stay Damp

Your Neighbour's Wall Is Wet Because of Your Bathroom

Water seeps through grout, through tiles, through the slab. The bedroom next door gets damp patches. The paint peels. Mould grows. The problem isn't the tiles — it's what's behind them.

Root Causes

No waterproofing layer under tiles — Most builders skip it. Tiles alone are not waterproof.
Failed grout joints — Grout is porous. Water passes through freely, especially at floor-wall junctions.
Structural movement cracks — Buildings settle. Rigid coatings crack and fail. Flexible systems stretch.
Wet area without proper slope — Standing water under tiles accelerates seepage.

Regrouting and waterproof paints are cosmetic fixes. They last 12–18 months. The system fix lasts 10+ years.

The Hardex Solution: CM200 2-Coat System

A flexible cementitious coating that bonds to the substrate, bridges micro-cracks, and creates a seamless water barrier — before the tiles go on.

Hardex Bathroom Waterproofing System

Layer 1 — PRIMER (SBR-50)
Bonding primer · Coverage: 0.10–0.15 kg/m² · Cure: 2–4 hrs (apply next coat while tacky)
Function: Adhesion to substrate

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Layer 2 — COAT 1 (CM200)
Flexible cementitious coating · Coverage: 0.8–1.0 kg/m² · Cure: 24 hrs
Function: Primary waterproofing barrier

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Layer 3 — COAT 2 (CM200)
Second coat perpendicular to first · Coverage: 0.8–1.0 kg/m² · Cure: 7 days before tiling
Function: Complete seal, redundancy layer

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FLOOD TEST — then tile
50 mm water for 24 hours · Check adjacent walls · Proceed to tiling on pass

Feature	Hardex CM200	Grout Only	Waterproof Paint
Flexibility (crack bridging)	✓ 350% elongation	✗ Rigid	Low
Bonds to substrate	✓ Cementitious bond	Surface only	Paint adhesion
Tile-ready surface	✓ Yes	✓ Yes	✗ No — needs prep
Durability	10+ years	2–3 years	1–2 years
Seals floor-wall junctions	✓ Yes	✗ No	Partial

Product Specifications

Product 1 — SBR-50 Bonding Primer (HC710)

0.10–0.15

kg/m² coverage

2–4

hours to tacky cure

1

coat required

Milky

white liquid

Best for: Creating adhesion bridge between old substrate and CM200. Essential — don't skip. Apply on damp (not wet) surface.

Product 2 — HARDPROOF CM200 Flexible Cementitious Coating

1.5–2.0

kg/m² for 2 coats

350%

elongation (crack bridging)

7

days cure before tiling

Best for: Bathrooms, toilets, balconies, kitchens, wet areas. Grey powder — mix with water. Tile directly over cured surface.

Application Timeline

Day 1 AM

Hacking & Surface Prep

Remove loose plaster, tiles (if redoing), effloresence. Fill cracks. Surface must be structurally sound.

⏱ 2–4 hrs for 10 m²

Day 1 PM

SBR-50 Primer

Apply primer to damp substrate. Work into corners. Wait until tacky — 2–4 hrs — then apply first coat immediately.

⏱ 1–2 hrs · Cure: 2–4 hrs to tacky

Day 1–2

CM200 — First Coat

Mix CM200 per ratio. Apply 0.8–1.0 kg/m². Work into floor-wall junctions with brush. Extra coat at corners.

⏱ 2–3 hrs · Cure: 24 hrs

Day 2–3

CM200 — Second Coat

Apply second coat perpendicular to first. Total coverage now 1.5–2.0 kg/m². Surface should be uniformly grey.

⏱ 2–3 hrs · Cure: 7 days

Day 9–10

Flood Test

Fill bathroom floor with 50 mm water. Leave 24 hours. Check adjacent walls and ceiling below for dampness.

⏱ 24 hr test · Pass = proceed to tiling

Day 10+

✓ Tile and Finish

Flood test passed. Apply tile adhesive directly over CM200. Proceed with tiling normally.

Total: 10 days start to tile-ready

Detailed Application Guide

Preparation — The Step Contractors Skip

Hack the surface — Create a rough texture for CM200 to bond. Use a chisel or angle grinder.
Fill cracks — Use FASTFIX crack filler on any cracks >0.5 mm. Allow 4–6 hrs.
Wet the surface — Substrate should be damp (not dripping) before primer. This improves adhesion.
Junction prep — Floor-wall junctions are highest failure points. Extra preparation here is critical.

SBR-50 Primer Application

Dilute SBR-50 with water (1:1 ratio). Apply by brush to entire surface.
Do NOT wait for full dry — apply CM200 when primer is tacky (2–4 hrs).
If primer dries completely, reapply before CM200 coat.

CM200 Application — Critical Points

Mix powder with clean water per TDS ratio. Mix to lump-free paste.
Apply first coat by brush — working into corners, pipe penetrations, drains.
Apply two extra coats at floor-wall junctions — this is where 80% of leaks start.
Second coat perpendicular to first — fills pinholes left by first coat.
Do not rush tiling — 7 days cure is minimum. Premature tiling causes delamination.

System Comparison — What Actually Works

Method	Hardex CM200	Waterproof Paint	Grout Sealer	Epoxy Grout
Crack bridging	✓ 350% elongation	✗ Brittle	✗ No	Partial
Tile over it	✓ Yes	✗ No	✓ Yes	✓ Yes
Durability	10+ years	1–2 years	2–3 years	5–8 years
Seals penetrations	✓ Yes	Partial	✗ No	✗ No
Flood test pass rate	✓ Yes	✗ Often fails	✗ Often fails	✓ Yes

The Bottom Line

Waterproof paint — Fine for walls above tile line. Fails under water pressure at floor level.
Grout sealer — Cosmetic. Doesn't address the substrate. Fails at junctions.
CM200 — Applied under tiles. Bonds to substrate. Bridges cracks. The only permanent fix.

Frequently Asked Questions

Can I apply CM200 over existing tiles without hacking?

Not recommended. CM200 needs a rough, absorptive substrate to bond. Glazed tiles have zero absorption. Hack and prepare properly for a permanent result.

My bathroom is already built and leaking. What do I do?

Option A: Hack tiles, apply CM200, re-tile (permanent fix). Option B: If hacking isn't possible, apply HARDPROOF CM200 to the exterior wall where seepage appears — limits damage but doesn't fix source.

How do I waterproof around pipes and drains?

Apply three extra coats of CM200 around pipe penetrations using a brush. Fill the gap between pipe and floor/wall with HARDPROOF PU350 sealant before CM200 application.

What tiles can go over CM200?

Any ceramic, vitrified, or natural stone tile. Use standard tile adhesive. CM200 surface is compatible with all standard adhesives and grouts.

CM200 vs CM300 — which for my bathroom?

CM200 is correct for bathrooms, balconies, and wet areas. CM300 is a heavier two-component system for basements and foundations under hydrostatic pressure. Overkill for bathrooms and more expensive.

How much CM200 do I need for a standard bathroom?

A 10 m² bathroom (floor + 1.5 m wall height) = ~35 m² total surface. At 1.5–2.0 kg/m², you need 55–70 kg of CM200. Buy 3–4 bags of 20 kg.