Weberkol Flex Extra

Weberkol Flex Extra is a polymer-modified, highly flexible tile adhesive mortar with reduced slip and extended open time. Classified as C2TES2 according to TS EN 12004-1, it provides reliable adhesion on demanding substrates, high-traffic areas, swimming pools, underfloor heating systems, and tile-on-tile applications.

Product Description

• Highly flexible, polymer-modified adhesive
• Reduced slip for vertical applications
• Extended open time for easier installation
• Advanced bonding performance for challenging surfaces

Applications

Weberkol Flex Extra is suitable for:

• Ceramic tiles
• Porcelain and vitrified tiles
• Marble and granite
• Glass mosaics
• Indoor and outdoor wall and floor installations
• Swimming pools
• Tile-over-tile applications
• Underfloor heating systems
• Primed gypsum surfaces
• High-traffic commercial and residential areas

Suitable Substrates

Interior Walls

• Cement-based renders
• Fair-faced concrete
• Gypsum plaster and gypsum boards (primed)
• Cement boards
• Existing ceramic tile surfaces

Interior and Exterior Floors

• Cement-based screeds
• Concrete floors
• Existing ceramic tile coverings

Exterior Walls

• Cement-based renders
• Fair-faced concrete
• Existing ceramic tile surfaces
• Glass mosaic systems with appropriate primer

Key Benefits

• Reliable tile-on-tile bonding
• Suitable for swimming pools
• Compatible with underfloor heating systems
• Excellent adhesion on primed gypsum surfaces
• High resistance to heavy foot traffic
• Ideal for large-format tiles
• C2TES2 certified performance

Surface Preparation

• Surface must be clean, dry, sound, and level.
• Remove weak or loose layers.
• Absorbent surfaces should be slightly dampened before application.
• Large cracks and holes should be repaired with suitable repair mortars.
• Minor repairs up to 7 mm may be carried out using Weberkol Flex Extra.

Application Conditions

• Application temperature: +5°C to +35°C
• Do not apply on frozen or thawing surfaces.
• Avoid direct sunlight, strong wind, and excessively hot surfaces.
• If surface skinning occurs, re-comb the adhesive before installation.

Mixing and Application

Mixing

For a 25 kg bag:

• Grey: 6.75–8.5 L water
• White: 6.75–7.75 L water

Mix with a low-speed mixer until homogeneous. Allow to rest for 5 minutes and remix before use.

Application

• Apply using a notched steel trowel.
• Double-sided application is recommended for:
  • Large-format tiles
  • Natural stone
  • Exterior applications
  • Granite and porcelain tiles

Consumption

Approximately 4–6 kg/m², depending on substrate and tile size.

Technical Specifications

Grouting and Traffic Opening Times

• Grouting (walls and floors): 24 hours
• Light foot traffic: 24 hours
• Heavy traffic: After 1 week

Storage

• Store in a dry, moisture-free environment.
• Keep packaging tightly closed.
• Shelf life: 12 months under proper storage conditions.

Frequently Asked Questions

Which tile types can be installed?

Ceramic, porcelain, marble, granite, and glass mosaic tiles.

Is it suitable for swimming pools?

Yes, it is designed for pool applications.

Can it be used with underfloor heating?

Yes, it performs well with underfloor heating systems.

Can it be applied on metal surfaces?

No. Metal substrates require a suitable epoxy bonding system.

When can grouting begin?

Approximately 24 hours after installation.

What is the recommended application thickness?

Between 3 mm and 10 mm.

Is double-sided application necessary for large tiles?

Yes, especially for large-format and exterior installations.

What should be done if a skin forms on the adhesive?

Re-comb the adhesive surface with the notched trowel before laying tiles.