Adhesive mortar FLL

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Product description

Adhesive Mortar FLL is a polymer-modified, cement-based mortar with a maximum grain size of 0.6 mm. 

  • The adhesive mortar for the Fescoterm thin-layer plastering systems’ insulation panels
  • Weather protection of thermal insulation on thin plaster elements, i.e. skimming



  • Additional thermal insulation of old residential, commercial and industrial buildings, and thermal insulation of new buildings
The product is listed in the portal for building products that can be used in Nordic Swan Ecolabelled buildings.
GTIN code Product name Product number Package size
6416841450234 Adhesive mortar FLL 45023 25 kg

Wash the old facade surface with a pressure washer to remove flaking paint and loose dirt. If necessary, remove flaking paint by scraping. Remove plastering that has come loose from its base and damaged concrete, and patch any cavities.


Refer to the bag for how much water the plaster requires. Add the dry material to the water and mix with a power mixer or a drill paddle for around one to two minutes.Allow the plaster to stand for around ten minutes and mix it again for a short while. Find the correct consistency at this stage by gradually adding the rest of the water. We do not recommend adding all of the water right at the start. The finished plaster remains workable for around four hours.

Work instructions

Apply adhesive plaster thoroughly to the insulation boards to be fastened using a toothed trowel. Then, press the boards into the base, tightly against each other. No plaster or gaps must remain in the joints. The joints of the insulation boards must be staggered, and there must be no joints that cross each other. Finally, secure the fastening of the insulation board to the base using fastening plugs made from polyethylene plastic. Use at least 4 plugs per m². The fastening plugs are installed at the corners of the insulation boards and evenly in their middles. After fastening, the facade surface must be level and the insulation boards undamaged.

Storage and handling of waste
See the separate storage and disposal instructions

Material usage

4 - 5 kg/m²/layer

Water requirement 6.0 - 6.5 l/25 kg
Finished compound 13 - 14 l / 25 kg bag
Type powder
Colour gray
Maximum grain size

0.6 mm

Package size 25 kg

in a dry location approx. 1 year

Lowest usage temperature


Workability time 4 h
Reaction to fire A2