Merks Sealmax CB 504 UV Full Elastic | UV-Resistant Cement & Acrylic Waterproofing Membrane

28/07/2026

Merks Sealmax CB 504 UV Full Elastic | UV-Resistant Cement & Acrylic Waterproofing Membrane

Merks Sealmax CB 504 UV Full Elastic: Durable Waterproofing for Exposed Areas

Merks Sealmax CB 504 UV Full Elastic is a two-component, cement and acrylic-based waterproofing membrane designed for long-term protection in areas exposed to sunlight and weather conditions. Its fully elastic structure and UV-resistant formulation make it an ideal solution for roofs, terraces, balconies, pools, and other exterior applications where waterproofing durability is essential.

The product combines excellent adhesion, flexibility, and resistance to environmental stresses, providing reliable waterproof protection for concrete and masonry structures.

Key Features

  • UV-resistant waterproofing membrane
  • Two-component cement and acrylic-based system
  • Full elastic performance
  • Suitable for exposed outdoor applications
  • Excellent adhesion to concrete and masonry
  • Can be applied by brush, roller, or trowel
  • Paintable after curing
  • Suitable for horizontal and vertical surfaces
  • Resistant to positive water pressure
  • Approved for contact with potable water

Areas of Application

Merks Sealmax CB 504 UV Full Elastic is suitable for:

  • Exposed roofs, terraces, and balconies
  • Gutters and drainage channels
  • Exterior wall waterproofing
  • Retaining walls
  • Swimming pools and decorative pools
  • Bathrooms, toilets, and wet rooms
  • Planters and landscaping elements
  • Concrete structures
  • Protective coating systems for bridges

Advantages

UV Resistance

Unlike many conventional waterproofing materials, the UV-resistant formulation allows long-term use in direct sunlight without significant deterioration.

High Flexibility

Its fully elastic structure accommodates substrate movement and helps prevent cracking within the waterproofing layer.

Excellent Adhesion

Provides strong bonding to concrete, cementitious surfaces, and other common construction materials.

Easy Application

Can be applied using brushes, rollers, or thin trowels with minimal effort.

Potable Water Compatibility

Suitable for applications involving contact with drinking water.

Surface Preparation

Before application:

  • Remove all dust, dirt, grease, oil, rust, and loose particles.
  • Clean heavily contaminated surfaces using water jet cleaning if necessary.
  • Repair cracks, tie-rod holes, and damaged areas using Merks Repair Plus repair mortars.
  • Lightly dampen the substrate before application.
  • Reinforce corners, joints, and pipe penetrations using Merks Bandix corner tape.

The substrate must be structurally sound and free from contaminants that could affect adhesion.

Mixing Instructions

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

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

Application Procedure

First Coat

Lightly dampen the substrate and apply the first coat using a brush in a single direction. Allow it to dry before proceeding.

Second Coat

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

Reinforced Applications

For large exposed surfaces, the use of a lightweight reinforcing mesh within the waterproofing system is recommended.

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 AWhite powder
Component BMilky white acrylic copolymer dispersion
Mixing Ratio20 kg powder / 7 L liquid
Powder DensityApprox. 1.35 kg/L
Liquid DensityApprox. 1.05 kg/L
Mixed DensityApprox. 1.55 kg/L
FlexibilityHigh
Pot LifeApprox. 30 minutes
Adhesion Strength≥ 1.25 N/mm² (28 days)
Positive Water Pressure Resistance5 bar
Water Vapor PermeabilityClass I (Sd)
Service Temperature-20°C to +80°C
Tile or Render ApplicationAfter 3 days
Application Temperature+5°C to +35°C
Shelf Life12 months

Packaging and Storage

Merks Sealmax CB 504 UV Full Elastic is supplied as:

  • 27 kg set
    • 20 kg reinforced kraft paper bag (powder component)
    • 7 kg plastic container (liquid component)

Store unopened packaging in dry, frost-free conditions. Shelf life is 12 months from the production date.

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.
  • Areas subjected to heavy pedestrian or vehicle traffic should be protected with an appropriate finishing layer.
  • Protect the liquid component from freezing. Frozen material must not be used.
  • Clean tools immediately after application with water.

Why Choose Merks Sealmax CB 504 UV Full Elastic?

Merks Sealmax CB 504 UV Full Elastic combines the benefits of high elasticity, strong adhesion, UV resistance, and long-term waterproof performance in a professional-grade waterproofing system. It is particularly suitable for exposed terraces, roofs, balconies, pools, and exterior concrete structures where both weather resistance and waterproofing reliability are critical.

Frequently Asked Questions (FAQ)

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

It can be used on roofs, terraces, balconies, gutters, walls, swimming pools, retaining walls, and a wide range of concrete structures.

2. Can it be applied in exposed outdoor areas?

Yes. Its UV-resistant formulation makes it suitable for direct exposure to sunlight and weather conditions.

3. How many coats are recommended?

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

4. Is it suitable for contact with drinking water?

Yes. The product is approved for potable water applications.