Base
The adhesive plaster (Fescon KS 10/90 or KS 35/65) must harden for at least one day before filling. If necessary, wet the base before applying the filler.
Mixing
Refer to the bag for how much water the plaster requires. Add the dry material to the water and mix with a concrete mixer for around ten minutes. With a power mixer or a drill paddle, around one to three minutes of mixing is sufficient. Let the plaster 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. Every batch must be mixed in the same way. The finished plaster remains workable for around two to three hours.
Work instructions
Apply the filling plaster with a plaster trowel or a pump. A suitable thickness for one layer of filler is around 15 mm. If the layer thickness exceeds 20 mm, the filler must be applied in several layers so that the previous layer has had time to dry for one to two days before the next layer is applied. In dry conditions, the base must be wetted before applying a new layer of plaster. Screed the filler plaster with a board. You can also carefully float the surface with a wooden tool to level the surface. Usage of dry plaster with a layer thickness of 15 mm
is approx. 30 kg/m². The lowest application temperature is +5°C and the recommended temperature is +10°C to +20°C. Plastering is not recommended in direct sunlight or in windy weather. Plastering nets mitigate the risk of cracking when mortar is drying. The net should be used especially at the connecting points of various materials, cracks in old brick walls, for reinforcing openings and corners, and plastering of various block surfaces (lightweight concrete, lightweight gravel, concrete). The correct position of the net in the plaster is 1/3 of the surface, however at least halfway outside.
After treatment
Filling plastering should be treated for at least three days with water irrigation. Aftercare should be started as early as possible to prevent plasticity cracks in the fresh mortar. In dry or windy conditions, aftercare should be started almost as soon as the mortar has sufficiently adhered to tolerate irrigation. If necessary, adhesive plastering should also be treated with water irrigation.
Other considerations
- For pumping render mortars and vertical joint concretes with a maximum aggregate size of 3 or 4 mm, it is recommended to use a sufficiently powerful rendering pump with a minimum power output of 5.5 kW and a stator size suitable for 7 or 8 mm aggregates. The use of automatic mixing pumps is not recommended, as the mixing time in automatic systems is too short. This may negatively affect the solubility of the mortar admixtures and the performance properties of the mortar.
Storage and handling of waste
See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank