Merks Sealmax CB 504 Super Elastic | Cement & Acrylic-Based Waterproofing Membrane

28/07/2026

Merks Sealmax CB 504 Super Elastic | Cement & Acrylic-Based Waterproofing Membrane

Merks Sealmax CB 504 Super Elastic: High-Performance Flexible Waterproofing Solution

Merks Sealmax CB 504 Super Elastic is a two-component, cement and acrylic-based waterproofing membrane designed to provide superior flexibility, strong adhesion, and long-lasting protection against water penetration. Enhanced with special polymers and cementitious components, it offers reliable waterproofing performance on a wide range of construction surfaces.

Its approval for contact with potable water makes it suitable for water tanks, swimming pools, and other sensitive waterproofing applications requiring high hygiene standards.

Key Features

  • Two-component cement and acrylic-based waterproofing system
  • Super elastic structure for crack-bridging performance
  • Excellent adhesion to mineral substrates
  • Suitable for horizontal and vertical surfaces
  • Can be applied by brush, roller, or trowel
  • Paintable after curing
  • Approved for contact with drinking water
  • Compatible with ceramic tile installations
  • High resistance to positive water pressure
  • Long-lasting waterproof protection

Areas of Application

Merks Sealmax CB 504 Super Elastic is suitable for:

  • Potable water tanks
  • Bathrooms, toilets, and wet rooms
  • Foundations and basement walls
  • Retaining walls
  • Roofs, terraces, and balconies
  • Swimming pools and decorative pools
  • Planters and landscaping structures
  • Protective coatings on bridges
  • Concrete and cement-based structures requiring flexible waterproofing

Advantages

Superior Elasticity

The highly flexible formulation accommodates structural movement and helps prevent waterproofing failures caused by substrate stress and minor cracking.

Strong Adhesion

Provides excellent bonding to concrete, render, cementitious surfaces, and masonry substrates.

Potable Water Compatibility

Suitable for waterproofing drinking water reservoirs and storage tanks.

Easy Application

The pre-measured liquid and powder components eliminate the need for additional water and ensure consistent application quality.

Tile-Ready Surface

In wet area applications, ceramic tiles can be installed directly over the cured waterproofing layer.

Surface Preparation

Before application:

  • Remove all dust, dirt, grease, oil, rust, and loose particles.
  • Clean heavily contaminated areas with high-pressure water if required.
  • Repair cracks, tie-rod holes, and damaged sections using Merks Repair Plus repair mortars.
  • Lightly dampen absorbent surfaces before application.
  • Protect the substrate from direct sunlight during installation.
  • Reinforce corners, joints, and pipe penetrations using Merks Bandix corner tape.

The substrate must be sound, clean, and capable of supporting the waterproofing system.

Mixing Instructions

  1. Shake Component B thoroughly before use.
  2. Pour Component B into a clean mixing container.
  3. Slowly add Component A while mixing with a low-speed mixer.
  4. Continue mixing until a homogeneous, lump-free consistency is achieved.
  5. Allow the mixture to rest for 3–5 minutes.
  6. Remix for approximately 30 seconds before application.

The prepared material should be used within 30–40 minutes at 20°C.

Application Procedure

First Coat

Lightly dampen the substrate and apply the first coat with a brush in a single direction. Allow sufficient drying time before applying the next coat.

Second Coat

Apply the second coat perpendicular to the first coat to ensure complete waterproof coverage.

Additional Coats

For areas subjected to high water pressure, additional coats may be applied to increase waterproofing performance.

Consumption

Application TypeConsumption
Per CoatApprox. 1.5 kg/m²
Standard Two-Coat Application3–3.5 kg/m²
High Water Pressure Areas4–5 kg/m² (3–4 coats)

Curing Times

PropertyTime
Mechanical Strength3 Days
Waterproof Performance7 Days
Final Strength14 Days

Technical Specifications

PropertyValue
Material CompositionMineral fillers, polymer-modified additives, special cement
Component AGrey powder
Component BMilky white acrylic copolymer dispersion
Mixing Ratio20 kg powder / 10 L liquid
Powder DensityApprox. 1.35 kg/L
Liquid DensityApprox. 1.07 kg/L
Mixed DensityApprox. 1.60 kg/L
FlexibilityHigh
Pot LifeApprox. 30 minutes
Adhesion Strength≥ 1.45 N/mm² (28 days)
Positive Water Pressure Resistance7 bar
Water Vapor PermeabilityClass I (Sd)
Service Temperature-20°C to +80°C
Tile or Render ApplicationAfter 3 days
Shelf Life12 months

Packaging and Storage

Merks Sealmax CB 504 Super Elastic is supplied as:

  • 30 kg set
    • 20 kg reinforced kraft paper bag (Component A)
    • 10 kg plastic container (Component B)

Store unopened packages in dry, frost-free conditions. Shelf life is 12 months when stored properly.

Important Notes

  • Apply only to surfaces exposed to positive water pressure.
  • Ambient and substrate temperatures must remain between +5°C and +35°C.
  • The second coat should always be applied at a 90-degree angle to the first coat.
  • Waterproofed areas should be protected with an appropriate finishing layer when exposed to mechanical loads.
  • Protect the liquid component from freezing. Frozen or thawed material must not be used.
  • Clean all tools immediately after use with water.

Why Choose Merks Sealmax CB 504 Super Elastic?

Merks Sealmax CB 504 Super Elastic combines exceptional flexibility, strong adhesion, and long-term waterproofing performance in a professional-grade system. Its suitability for potable water contact, swimming pools, terraces, foundations, and wet areas makes it a versatile solution for demanding waterproofing projects.

Frequently Asked Questions (FAQ)

1. Where can Merks Sealmax CB 504 Super Elastic be used?

It is suitable for water tanks, swimming pools, terraces, roofs, balconies, wet rooms, foundations, retaining walls, and various concrete structures.

2. Is it approved for contact with drinking water?

Yes. The product is suitable for potable water storage applications.

3. How many coats should be applied?

A minimum of two coats is recommended. Additional coats may be applied in areas exposed to high water pressure.

4. Can ceramic tiles be installed over the membrane?

Yes. Ceramic tiles can be installed after the recommended curing period has been completed.

5. What makes the Super Elastic version different?

Its enhanced elasticity and higher water-pressure resistance provide improved performance in demanding waterproofing applications where substrate movement and structural stress may occur.