Base requirements and coating conditions
The base should be cement or concrete, with minimum compression strength 25 MPa and minimum tensile strength 1.5 MPa. The base temperature must be at least +3⁰C above dewpoint. During coating work and drying of the coating, the temperature of the ambient air, the base and the coating must be between +8 and +25⁰C and relative humidity must be below 80%. Make sure that the coating is suitable for the surface to be coated.
New concrete floor
Laitance and any uncured cement are removed e.g. by diamond grinding the surface. All loose material that could negatively affect adhesion is removed, and cement dust is carefully vacuum-cleaned.
Old concrete floor
The laitance and damaged concrete are removed e.g. by diamond grinding. All loose material that could negatively affect adhesion is removed, and the base is carefully vacuum-cleaned. Dirty floors should be washed and rinsed with synthetic detergent before performing any other base treatment work. Any old coat is removed completely. Possible surface castings or slope repairs are carried out with Fescon Repairing Plasters or Repair Concrete RKB, see Fescon's design and work instructions for concrete balconies for details.
Priming
Concrete bases are primed with Nanten EP Primer epoxy (RH of the concrete < 95%). The carefully mixed primer is rolled or spread onto the base, or applied with a rubber spreader. Highly porous bases are primed twice. The primer is formed into an intact membrane, without any pores on the surface. The coating is applied after the primer has dried, within 12 to 48 hours depending on the conditions. If the coating is applied more than 48 hours from the priming, the primed surface must be roughened and grinding dust must be removed. It is recommended that the primer be freshly sanded with clean, kiln-dried sand, as there will be no time limit for the coating after that. Good ventilation must be ensured in the workspace as needed. Plywood bases are primed with Nanten PU Flex UV polyurethane coating.
Patching work
Patching and straightening are done with Fescon repairing plasters or Repair Concrete RKB in accordance with product data sheet instructions. Small patching and straightening work can also be done with a paste made of PU Flex UV coating and back sand.
Mixing
Premix component A and add component B (curing agent) to component A. Mix with a slow-speed mixer for two minutes, avoid mixing air into the paste. Make sure to reach the edges and bottom of the container with the mixer. Finally, pour the mixture into another container and continue mixing for another minute, avoiding mixing air into the paste.
Mixing ratio
Component A 3 mass fractions and component B 1 mass fraction. It is recommended to prepare a full container at a time to avoid dosing errors.
Spreading rate
Minimum layer thickness 1 mm. Consumption at 1 mm membrane thickness 1.22 kg / mm / m2. About 2 kg/m was used for coating. Minimum layer thickness 1.5 mm.
Work instruction
If the coating is done more than 48 hours from the priming and the primer has not been sanded, the primed surface must be roughened and the grinding dust must be removed. The mixture is poured onto the floor in a continuous flow that is then applied at the desired thickness with an adjustable or toothed steel trowel. After application, use a spiked roller to remove air bubbles. The mixing container must not be drained onto the base to be coated. Do not apply in direct sunlight or in excessively humid conditions, see Base requirements and coating conditions. Inadequate mixing may result in uneven curing or discoloration. Vertical surfaces are coated using brushes and, if necessary, the coating is thickened with a suitable product. The coating can also be roughened with sand or glass beads. Decorative flakes are added immediately after application of the coating.
Storage and handling of waste
See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank