The brick surface and the plaster surface to be repaired must be clean and undamaged. If necessary, wet a dry surface while retaining the absorption capacity of the base, the running water must not be visible. Use the same lightweight lime-cement plaster for patching. The patches must be allowed to dry sufficiently before the entire surface is plastered. Adhesion plastering is not required, but if it is done, it should be done with the same product.
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 three to five minutes. With a power mixer or a drill paddle, around one to three minutes of mixing is sufficient. 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. Every batch must be mixed in the same way. The finished plaster remains workable for around two to three hours.
Apply the filling plaster with a plaster trowel or a pump. A suitable thickness of one filling plaster layer is 10-60 mm in overlevelling and 10-100 mm in patching. If the required layer thickness is greater, do the work in several layers. In dry conditions, the base must be moistened with each filling. Screed the filler plaster with a board. You can also carefully float the surface with a wooden tool to level the surface. You can use plastering mesh to reduce the cracking risk caused by the drying of the plaster and cracks in the base. You should in particular use a mesh at the joints of different materials, as reinforcement near openings and corners, and when plastering Siporex surfaces.
Plastering must be protected with a plastic film or light spraying of water (the water must not flow) for at least one to three days. When the temperature is:
+20°C, protect the fresh plaster surface from rain and strong sunlight for one day
+10°C, protect the fresh plaster surface from rain for three days
+5°C, protect the fresh plaster surface from rain for seven days
Storage and handling of waste
See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank