Product description

Fescon FlowFiber is a fibre-reinforced, low-alkali (Ph < 11) pump-applied levelling compound with a special cement binder, which is both self-smoothing and features excellent workability characteristics.


  • For layer thicknesses 8 - 50 mm (partial levelling 8 - 80 mm)
  • Can be pump-applied and manually levelled
  • Heated floors of housing construction, and pump levelling of floors.
  • Floating floor systems
  • For alkali protection
  • Fibre-reinforced




  • For levelling hollow slabs and concrete floors of housing construction 
  • Heated floors and floating floor systems
  • Thick layers of levelling compound
The product is listed in the portal for building products that can be used in Nordic Swan Ecolabelled buildings.

Vinkki! Vieritä taulukkoa sivuttain
EAN code Product name Product number Package size
6416841331465 FlowFiber 1000 kg 33146 1000 kg


  • Concrete bases, hollow slabs, cement-based filler surfaces, wood and gypsum based boards and insulating boards
  • The base is clean, solid, dust-free, and vacuum-cleaned
  • Loose layers, cement paste, and other impurities have been mechanically removed to ensure adhesion between the floor levelling compound and base
  • The base must be sufficiently strong and immobile, and have a sufficient load-bearing capacity
  • The tensile strength of the base must be > 0,5 MPa. The floor must be made into a floating, fiber-reinforced structure, if the base is of weak concrete (tensile strength of the base < 0.5 MPa), wood or gypsum-based board, or insulating board. The floating floor structure must be detached from the base floor by Fescon Separation fabric and from vertical structures by Fescon Bordering strip
  • The temperature of the underfloor structure is > +10 °C and relative humidity < 95% RH The relative humidity of the underfloor structure affects the setting of the floor levelling compound
  • If need be, any rough areas are filled by Fescon LM 5000 or Flow HS before the floor levelling compound is applied
  • Possible leakage areas are sealed with putty
  • Priming is performed according to the instructions of Fescon Adhesive Primer or Flow Primer, depending on the base
Instructions for use
  • The workspace must be protected all over against wind, draught, sun, and rain
  • When pumping, the minimum layer thickness must be checked with the floor work contractor
  • During floor work, the indoor temperature has to be +10…+25 °C, and the relative humidity of the indoor air > 40 % RH
  • Mix a bag (20 kg) of the levelling compound in 3.6-4.0 litres of cold water
  • Do not use more water than instructed, because it will reduce the strength values of the floor levelling compound, increases the risk of separation, and adds to the setting time of the floor levelling compound
  • Mix the levelling compound carefully and for long enough so that it turns into a consistent paste
  • Apply the levelling compound with a steel trowel or pump it onto the surface being levelled
  • Workable for about half an hour after adding water
  • Wash tools with water immediately after completing the work
  • Make sure ventilation is adequate after finishing the floor levelling compound work.
  • If need be, the setting of the floor levelling compound can be accelerated by grinding the surface because this reduces the resistance of water vapour in the surface of the floor levelling compound
  • The setting times are greatly affected by the conditions at the work site, ventilation, and the amount of water used in the floor levelling compounds
  • Pumping from a tanker lorry is not recommended < -25°C
  • The floor load capacity is estimated work site specifically with the floor levelling contractor
  • Can be coated with ceramic tiles, plastic coatings, textile mats, vinyl tiles, wood parquet or laminate, and cork. If necessary, overlay with Fescon manually-applicable levelling compounds, such as FlowPlan
  • FlowFiber meets the strength requirement according to by 45 / BLY 7 table 1.15 for surfaces in living spaces and in utility spaces comparable with living from the viewpoint of strain when the coating is a plastic mat or tile, cork tile, or linoleum
  • However, it must be ensured that the levelling compound, concerning its technical properties, meets the requirements of the manufacturer of the floor covering and RYL for bases to be covered, with the entire structure in mind
  • Once the floor levelling compound has reached the degree of dryness required by the covering, the floor is covered or aftercare commenced
  • The floor levelling compound must not be left uncovered for more than 3 months due to the risk of it cracking or detaching
  • Check the humidity of the entire floor structure before installing a coating
  • Good setting properties for the floor levelling compound require that the indoor humidity is less than 50 % RH and the temperature is over 20 °C. Poor conditions slow down the development of the strength characteristics of floor levelling compounds and increase the setting time
  • In conditions with an RH of less than 40%, special attention should be paid to when to start the aftercare. The need for aftercare is assessed on a case-by-case basis

Floor heating with water circulation may be started after seven days from applying the floor levelling compound. The water temperature is first set to +20°C. The final water temperature may be applied after the floor covering is installed. Higher water temperatures cause a major decrease in the strength characteristics of the floor levelling compound and an increase of it cracking, so they must be avoided at all costs.

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

approx. 1,7 kg/m²/1 mm

Water requirement 3,6 – 4,0 l / 20 kg (125 – 135 mm:n flow as measured by Fescon flow plate)
Type powder
Binder special cement
Colour grey
Maximum grain size

1,2 mm

Package size 1000 kg

storage time in a dry location approx. 12 months

Layer thickness

8 – 50 mm (partial levelling max. 80 mm), as a floating floor structure min. 30 mm over a floor heating pipe min. 16-20 mm


Fibre fibre-reinforced, plastic fibre

Substances improving workability. Casein-free.

Usage temperature

+ 10°C – + 25°C

Workability time approx. 0,5 h
Coatable n. 1 – 8 week (+20 °C, RH 50 %)
Walkable approx. 4 - 6 h
Strength class C 16 (EN 13813)
Compressive strength

> 16 MPa (28 day +20 °C, RH 50 %)

Adhesion strength

> 1,0 MPa for concrete (28 day +20 °C, RH 50 %)

Flexural bond strength F 4 (EN 13892-7)
Frost resistance Non-frost resistant. For indoor spaces.
pH < 11 low alkaline (hardened material).


Product videos

Work images

Fescon rakennekuva flow hs

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.


Enter amount