Base requirements and coating conditions
The concrete must have a minimum strength class of C25/30 and wear resistance class 3. The relative humidity of the concrete must be below 90% when priming is done with a polyurethane coating. For epoxy-based primers, see section “Priming Treatment.” The surface temperature must be at least +3°C above the dew point. During application and curing, the temperature of the air, surface, and coating must be above +15°C, and the relative humidity must be below 70%. Ensure the suitability of the coating for the substrate to be treated.
New concrete floor
Cement laitance and any uncured cement must be removed by surface grinding or shot blasting. All loose and adhesion-reducing material must be removed, and the surface must be thoroughly vacuumed to remove all cement dust.
Old concrete floor
Cement laitance and deteriorated concrete must be removed by grinding or shot blasting. All loose and adhesion-reducing material must be removed, and the surface must be thoroughly vacuumed. Dirty floors should be washed and rinsed with a synthetic detergent before any further surface preparation. Any existing old paint film must be completely removed from the substrate.
Priming
Priming is done with Nanten HM Bio Epoxy (for concrete with RH < 95%) or with Nanten M Primer for damp concrete (RH < 98%). Dilution may be used on concrete substrates if necessary. Adequate ventilation must be provided in the work area. The primer must seal all pores in the concrete to form a dense and continuous film on the surface. Apply a second coat if necessary.
Patching
Small holes and cracks are cleaned and filled with a putty made of, for example, PU Flex Bio Coating and fine filler sand. Larger leveling work can be done using a levelling mortar made of Nanten PU Flex Bio Coating and filler sand (0.1–0.6 mm).
Mixing
Pre-mix Part A and Part B in their own containers. Combine the components in the correct ratio and mix with a low-speed mixer for approximately two minutes, avoiding air entrapment in the mixture. Pour the mixture into a second container, add the required amount of filler sand while mixing, and continue mixing for about one more minute.
Note: Component A separates into layers during storage. Before use, mix Component A thoroughly until completely uniform, then add Component B. Use the entire product at once; do not use in portions.
Mixing ratio
Part A: 5.52 parts by volume (13.8 l)
Part B: 1 part by volume (2.5 l)
Application instructions
If the priming is older than two days, the surface must be roughened by sanding and all sanding dust must be removed. The mixed material is poured onto the floor in a puddle or continuous bead and spread with a notched trowel to the desired thickness. As the work progresses, the surface should be rolled with a spike roller to remove air bubbles. Do not scrape or pour the remaining material from the mixing container onto the substrate.
Do not apply in direct sunlight or under damp conditions. Inadequate mixing may result in uneven curing or color variation.
Storage and handling of waste
See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank