Waterproofing compound WS

Product description

Fescon Waterproofing Compound WS is a water-soluble, one-component, high-quality waterproofing compound for indoor spaces.  

  • easy to apply
  • sufficient dry film thickness easily with just two applications
  • very elastic
  • also suitable for spraying
  • M1 and EC1 rated
  • Certificate No. C-12511-18


  • Waterproofing of floors and walls in indoor areas when the surface will be ceramic tiles
  • Suitable for concrete, lightweight concrete, plasterboard, levelling and plastering bases
  • Not suitable for outdoor use or in areas under constant water load, such as pools
  • Must not freeze even when dry, for example outdoor saunas
The product is suitable for use on sites with a Nordic Swan Ecolabel.

Vinkki! Vieritä taulukkoa sivuttain
EAN code Product name Product number Package size
6416841769091 Waterproofing compound WS 76909 3 l
6416841769121 Waterproofing compound WS 76912 15 l


  • If necessary, mix the insulation before use.
Pretreatment of the base
  • The base must be dry, dust-free and level, solid and immobile, and free of substances that reduce adhesion
  • Remove any cement paste and weak or eroded surface
  • The recommended moisture of the base is <85% RH, and the maximum moisture is <90% RH
  • Level uneven floors with Fescon Floor Levelling Compound and walls with Fescon Levelling Compound for Wet Areas WTT
  • Treat the bases with Fescon Primer KP according to the instructions
  • Switch underfloor heating off two days before waterproofing
Spreading the waterproofing compound

The temperature of the room and the base must be +10 - +30 °C. The working conditions must remain constant throughout the entire work.

Spread the waterproofing compound first into corners, joints, lead-throughs and around the floor drain. Attach the waterproofing fibre fabric to these locations with a brush or roller (accessories of the VE or FS series are also suitable). Make sure that the strip is wet throughout. Drain flange flexible KL-B 370x370 mm (installed on set adhesion promoter). Do not apply waterproofing compound inside the floor drain.

Next, apply the waterproofing compound to the entire area to be treated. Allow to dry for 3-4 hours, depending on the conditions at the worksite. After drying, the waterproofing compound is blue in colour. Apply a second layer of the waterproofing compound. Cut a hole at the floor drain with a diameter 40 mm smaller than the drain diameter, fold and clamp the membrane to the inner surface of the drain using a clamp ring. Allow to dry for five hours before beginning to lay tiles. Wash tools and equipment with water immediately after completing thee work.

A sufficient minimum dry film thickness can achieved by a usage of approx. 0.7 l/m2 (min. 1,0 kg/m2). The dry film thickness must be min. 0,5 mm. 

Waste handling

Storage and handling of waste. See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank

Technical information

Material usage

walls and floor: approx. 0.7 l/m2  (min. 1,0 kg/m2)

Colour Light blue, darkens when drying
Package size 3 l / 4,5 kg and 15 l / 22,5 kg

12 months in a warm location


1 l = 1.5 kg

Lowest usage temperature

+ 10°C

Drying time

3 h/1st treatment (+20 oC). Approx. 5 h after the second treatment before tile laying (colour change)

Film thickness Min. 0,5 mm (both walls and floors)
Method of application brush, roller or spray
Transport Warm transport

The information is based on tests and practical experience. We cannot affect conditions at the work site so we cannot assume responsibility for the end result affected by local conditions.


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