Kiilto Airblock Fiber
Coating against air leakages

A one-component, fibre reinforced, water-based, solvent-free and paste sealing agent. Can be applied with a brush or roller on vertical, horizontal and ceiling surfaces.

Special features

  • a very elastic coating against air leakages
  • paste
  • paintable
  • for sealing penetrations, window and door junctions, floor and wall junctions as well as wall and ceiling junctures. For interior use.
  • tested and approved for radon




A very elastic, water-based paste coating against air leakages indoors. Easy to apply. Tested and approved to be used also as a barrier against radon diffusion. Excellent adhesion on different types of substrates. Suitable for vertical, horizontal and ceiling surfaces, junctures and joints as well as penetrations. Suitable for unheated interior areas.

Package Size EAN Code
10 kg/8,1 l 6411512708102
Application temperature

+15–25 °C

Bond strength

Different substrates Concrete: 2.1 MPa
Coarse floor levelling compound: 1.3 MPa (Kiilto 70)
Smooth levelling compound: 1.6 MPa (Kiilto TopPlan)
Brick: 1.8 MPa
Chipboard: 1.5 MPa
Stainless steel (metal): 2.1 MPa
Aluminium: 1.9 MPa
Kiilto Block: 2.8 MPa
Kiilto Hydrablock: 2.7 MPa
Sand lime brick, chipboard, gypsum board and wall plasters: The adhesion exceeded the substrate strength

Classifications and certificates





A fibre reinforced paste


Approx. 1kg/m²

Crack bridging ability

3.8 mm (EN 1062-7 (mod))
With Kiilto Kerasafe Saumanauha sealing tape or Kiilto Butyylinauha Butyl tape >10 mm

Density/specific weight


Frost resistance


Layer thickness

approx. 0.4 mm dry coat
(approx. 0.9 mm wet coat)

Package sizes

10 kg / 8.1 L


Can be stored above + 1 °C, in a tightly sealed original container max. 1 year.

Temperature resistance when dry

-20…+70 °C


SBR hybrid


Approx. 65,000 mPas

Water vapour permeability

Sd = 18 m
Vapour permeability (EN ISO 12572:2001 condition A)


approx. 9

Instructions for use

Stir the product before use. Remove all impurities that might impair adhesion, including loose particles, dust, dirt and salt deposit. Fill in dents and holes beforehand. Apply at least two even coats of Airblock Fiber. The second coat can be applied right after the first one (wet on wet). Drying time depends on the prevailing conditions and coat thickness.
Kiilto Airblock Fiber can be used with Kiilto Butyylinauha tape or Kiilto KeraSafe Saumanauha sealing tape, if necessary. Porous substrates can be primed with diluted (1:1) Kiilto Keraprimer before applying Kiilto Airblock Fiber, if necessary.

Tools: a brush or roller.

When uncoated, the product’s resistance to mechanical wear and UV light is limited. The need for levelling and coating of the product must be assessed on a case-by-case basis.

1. Left as the final surface.
2. Painted with standard water-based finishing paint suitable for indoor use, e.g. Tikkurila Luja or Teknos Trend.
3. Smoothed with Kiilto Pro LM or Kiilto Pro LW plaster and painted over.

1. Tiled if the floor is sufficiently straight and even. Tiles are placed straight on the Kiilto Airblock surface, without using a primer. Use Kiilto Floorfix DF or Kiilto Floorfix DF Rapid floor adhesive.
2. Covered with loose lay parquet or laminate, checking first whether the floor is sufficiently straight and even.
3. Levelled with self-levelling adhesive if you want to add coverings (either glued or loose lay) such as plastic flooring, tiles or vinyl plank flooring (excluding parquet glued to the substrate). The Kiilto Airblock surface to be levelled must be free of any materials that reduce adhesion. Before levelling, the surface of Kiilto Airblock Coat is primed with Kiilto Pro Fix Primer. Use Kiilto TopPlan DF smoothing compound up to 10 mm, and if you need a thicker layer, Kiilto Floor Heat DF levelling screed or Kiilto Tasoflex floor levelling compound. The Kiilto Airblock surface to be levelled must be free of any materials that reduce adhesion.
Minimum thickness of levelling material:
Room of light traffic, such as residential areas 5 mm.
Rooms with medium traffic, such as offices and meeting rooms 10 mm.

Additional information

The information given in this product data sheet is based on our tests and our practical knowledge. The technical data is defined under standard conditions. Variations in local working conditions and methods will affect the product performance and result. The result is also strongly affected by working methods. We guarantee the high quality of our products according to our Quality Management System. No liability can be accepted from incorrect use of the product or prevailing conditions, over which we have no control. Therefore, we cannot be held responsible for the final result. To use the product properly, please read the product brochure, work instructions and the safety data sheet available at

Environment and safety

Avoid unnecessary skin contact and exposure with the fresh product, use safety gloves. Refer to the material safety data sheet. For more information about the product and package disposal, visit