Base
Remove damaged concrete, for example by chiselling or water sand blasting. Shape the cavities and clean any rusted reinforcement bars or, if necessary, replace them with new ones. Apply one or two layers of Fescon Adhesive Plaster to the cleaned reinforcement bars. Clean the base of loose dust and dirt, for example by pressure washing. The surface must be damp enough to be darker in colour before coating begins. The best time to wet the surface is the previous night.
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 two 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. The finished plaster remains workable for around two hours.
Coating
Fescon Repairing Plaster 1.2 mm is sprayed throughout into a layer about 3 mm thick. Level the surface if necessary. You should not float the surface to bring the cement paste to the surface. After the surface has hardened for at least a day, spray a second layer of repairing plaster, if necessary, into a layer about 3 mm thick. Level and float or brush the plaster into the desired profile. You should always carry out the finishing very carefully in order not to reduce adhesion to the base.
Repairing
Begin repairs by first patching up any deep cavities. Choose the largest possible grain size for the repairing plaster according to the depth of the cavity. Recommended layer thickness is 2-15 mm. Best adhesion to the base can be achieved using Adhesive Plaster and filling layer by layer. Each layer must be allowed to harden for at least one day before the next application. Always leave the surface of the previous fill layer rough. You should carry out the finishing very carefully in order not to reduce adhesion to the base. For structural repairs, you should use, for example, Fescon Repair Concrete RKB.
After treatment
You must care for both repaired and coated areas by spraying with water and/or protecting them with a plastic film. The need for aftercare depends on the conditions. It should continue for at least one to three days.
Storage and handling of waste
See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank