Crack and Gap Filler – A4

A4 is a one-component polymeric mastic with excellent filling and covering properties. The product is elastic, resistant to UV radiation, sun, and weathering, can be painted, is durable and non-flammable. Excellent adhesion to all types of dry and absorbent surfaces.

Areas of Use

• Filling cracks before applying water-based paints and coatings

• Dilatation and expansion joints

• Sealing chimney joints

• Joints and gaps

• Skirting boards and joints in cladding (stone, ceramic, marble, etc.)

• Filling or repairing cracks and holes

• Additional joints for gutters and prefabricated facades

Technical Specifications

• Density (25°C, g/mL): 1.40 ± 0.10

• pH (25°C): 7.0 – 9.0

• Viscosity (25°C, mPa.s): > 70,000

• Solid content (% by weight): 74 ± 2

• Water absorption rate (kg/m²·h⁰,⁵): < 0.1 (Class W3)

• Adhesion to pull-off test (N/mm²):

  • Flexible systems without traffic: ≥ 0.8

  • Systems with traffic: 1.5

• Vapour permeability (m): SD < 5 (Class I)

• Touch dry: 3 – 6 hours

• Full cure: 72 hours

• Pot life (23°C): –

• Solvent: Water

• Fire reaction class: B S1 d0

• Color: White (can be colored on request)

Application Procedure

Surface preparation:

• The surface must be clean, dry, and free of dust, oil, dirt, or other impurities that reduce adhesion.

Application method:

• After opening the packaging, mix the product for 2 minutes until homogenized.

• For expansion/dilatation joints, it is recommended to use a PE backing rod before applying the mastic.

• For corners and details, a reinforcing mesh is recommended.

• The product is applied with a spatula or mastic gun, directly into the joint or crack.

• After filling, the surface is leveled with a damp sponge.

• Maximum application thickness in one layer: 5 mm.

Application Conditions / Limitations

• Application: crack filling

• Surface moisture: dry

• Product consumption: approx. 30 g for 5 mm thickness and 1 m length

• Coverage (18 kg bucket): ~120 m for a 10×10 mm joint

• Recommended tools: spatula, mastic gun

• Application temperature: 5 – 35 °C

• Do not apply on wet surfaces or in humid air.

IMPORTANT

The surface must be protected from rain, water, mechanical shocks, and loads for 24 hours after application.

Packaging & Storage

• Packaging: 5 kg and 18 kg PP buckets

• Storage temperature: 5 – 35 °C

• Shelf life: 24 months from manufacturing date (in original, unopened, and undamaged packaging)

• Conditions: keep tightly closed, in a dry and cool place