2K sealing membrane

2K sealing membrane

For waterproofing of wet room surfaces prior to installation of ceramic tiles. Suitable for both domestic and communal locations.
ETA-approved in accordance with Etag 022

  • For interior and exterior use
  • Working time is approx. 3 hours
  • Crack bridging, anti-fracture membrane
  • Approved for wet rooms
  • Pools – max. depth 15 m
  • Suitable for use on basement walls, balconies, and terraces
  • Rapid setting
  • Smooth consistency and good workability
  • Approved for radon protection

Product calculator

Product facts


Alfix 2K Sealing Membrane, 2-part tanking system consisting of:
1. Alfix 2K Binder, polymer dispersion
2. Alfix Quick cement

Available in standard grey and through-coloured white.




Approx. 1.2 - 1.5 kg/m² per mm coat thickness.


10 kg plastic buckets.



Expected Result



Surface preparation

Fixing dowels



For sealing around floor drains, use self-adhesive Alfix Drain-mat.

Remove half the protective silicon paper along the perforated line and subsequently fix to substrate and gully installation. Degrease gully flange before overbridging with drain mat.

Remove any clam ring!
In junctions between wall and floor, for internal vertical corners, and around pipe penetrations or sanitary installations, use self-adhesive Alfix Seal- Strip.

Application of Alfix Seal Strip is made by folding the strip together along the longitudinal cross cut and subsequently removing the protective silicon paper along the perforated line. Press the strip firmly to the substrate.

Alternatively, use Alfix Reinforced Strip bedded in sealing membrane.
For bridging over cracks and for reinforcing joints, use Alfix Reinforced Strip bedded in Alfix Sealing Membrane 2K.



Alfix A/S H.C. Oersteds Vej 11-13 DK-6000 Kolding alfix.com

Alfix 2K


Declaration of performance
No. 18


Alfix A/S H.C. Oersteds Vej 11-13 DK-6000 Kolding alfix.com
Declaration of performance
No. 18

EN 14891:2012
Alfix 2K
Liquid-applied water
impermeable product
for internal and
external installations
on walls and floors,
ceramic tiling
EN14891: CM O1P

Initial tensile adhesion
≥ 0,5 N/mm² Tensile adhesion
strength after water
≥ 0,5 N/mm²
Tensile adhesion
strength after heat
≥ 0,5 N/mm² Tensile adhesion
strength after contact
with lime water
≥ 0,5 N/mm²
Tensile adhesion
strength after freezethaw
≥ 0,5 N/mm² Waterproofing No penetration
Tensile adhesion
strength after contact
with chlorinated water
≥ 0,5 N/mm² Crack bridging ability: ≥ 0,75 mm
Crack-bridging ability
at low temperature at
-5 °C
≥ 0,75 mm Release of
See material safety data
sheet www.alfix.com

Tile fixing

Tile fixing

For tile fixing, use Alfix LetFix Universal, Alfix LetFix or Alfix CombiFix depending on substrate and tile.


ETAG 022 part 1 and 2.
The product also fulfil the requirements for use in pools, according to the guiding principles in German building regulations:
”Testing principles for being granted a general technical approval or test certificate from the building authorities, for sealing materials in combination with tiles and surface coatings – part 1: Composite - sealing systems for fluid sealing applications.“ Issue February 2008.


Technical data

Working temperature

+ 10°C - + 30°C


1.2 – 1.3 kg/litre

Working time

Approx 2 hours

Drying time

First coat: 1 hour at +20°C
Second coat: approx. 6 hours at +20°C

Tile fixing

Approx. 6 hours after applying last coat days at +20°C

Curing time

14 days at +20°C

Tensile adhesion strength concrete :

0.8 – 1.2 N/mm²

Temperature resistance


Shelf life

Min. 6 months in unopened packaging. Keep free from frost at stable temperatures ranging between 10–25°C. If exposed to large fluctuations in temperature, the binder part may become lumpy.

How to use


Cement/sand rendering, older than 2 days
Concrete, older than 14 days, max. 90% relative humidity
Lightweight concrete, max. moisture content 8%
Aerated concrete
Screed, older than 2 days
Existing tiles and terrazzo.
Plywood, only floors. Max. moisture content 7 - 12%
Gypsum plaster, fibre-reinforced plasterboards, plasterboards.
Cementious boards suitable for wet room use.

Surface preparation

The surface should be dimensionally stable, sound, and clean. Free from laitance, grease, and dust. There should be no blooms, crack formations, or residues from form oil.

All absorbent, moisture-sensitive surfaces, such as rendering, brick work, aerated concrete, concrete, light-weight concrete, screed, cementious or PVC boards should be primed with Alfix Primer (Sealing Primer), diluted 1:1 with water.

Plaster boards for wet room use and fibre-reinforced boards should be primed twice with Alfix Primer undiluted to full coverage.

For other wet room boards, please consult our Technical Services Dept.
Plywood (floors only) should be primed with 2 applications of Alfix Primer; first coat should be applied diluted 1:3 with water. Second coat applied undiluted.

Existing tiles and terrazzo should be cleaned with Alfix Deep Cleaner.

How to use

Carefully add Alfix Quick Cement to Alfix 2K Binder in the proportion 1:1 while stirring with a rotating drill. Mix until a smooth, lump-free paste is obtained. Working time is approx. 2 hours
Apply sealing membrane to the surface to full coverage leaving no voids.
For wet room use, coverage should be 1.2 - 1.5 kg/m².
For pools and basement walls, coverage should be 2.5 kg/m².
Apply 2-3 applications with steel trowel. First application should be a thin pore filling coat leaving no voids. Subsequent applications should be made with 4x4 mm notched trowel. Complete by smoothing the surface with straight trowel edge. When used in wet rooms, ensure that Reinforcing Tape, Seal-Strip, and Drain mat are completely over-bridged.
For pools and basement walls, only use Alfix 2K Sealing Membrane in standard grey and Alfix Reinforcing Strip.

Drying time after first coat: 0.5 – 1 hour
Drying time after second (and third) coat: approx. 6 hours
Even by low temperatures or exposed to high humidity total drying time will not exceed 24 hours.


Mixing of subvolume: Mixing ratio: 3 parts binder to 1 part cem ent by weight/volume. For example, measure 0.5 litre of cement and 1.5 litre of binder in a clean bucket of su itable size, and mix with stirrer on drilling machine to a smooth mixture.
During work substrate and membrane should hold the same temperature. Protect membrane from heat or draught.
Thicknesses exceeding 2 mm may cause crack formations.


Tools should be cleaned with water before residues start to set. Once set, 2K Sealing membrane can be removed mechanically.

January 2021

Happy New Year! Team Alfix is back from Christmas holidays and ready to serve our good Scandinavian customers.

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