SUBSTRATE PREPARATION
The surface shall be cleaned thoroughly of all contaminants like dust, traces of curing compound, oil and grease. All surface imperfections, protrusions, structurally unsound and friable concrete must be removed and repaired.
PRIMING
It is highly recommended to apply a priming coat prior to the application of the Polycoat RBE coating on the substrate. The primer can be prepared in the site by diluting Polycoat RBE with 20% water and applying this diluted coat as the primer. For very dry and porous substrates apply two coats of this primer. The primer can be applied to damp or freshly cast concrete surfaces also. However, it should not be applied on waterlogged or flowing water areas. Further coats shall be applied only after the primer coat dries off completely. In case of delay in application of the top coat for more than 24 hours, a fresh coat of primer shall be re-applied.
APPLICATION
Stir the contents of the drum thoroughly before application to remove all sediments. Depending on the dry film thickness required, apply the rubberized bitumen coating 1–4m²/L/coat. On vertical areas, it is recommended to apply the coating in multiple layers in order to avoid sagging of the heavy bodied coating. Subsequent coats shall be applied only after the previous coat dries off completely and shall be applied at right angles to the previous coat. Clean dry sand may be broadcasted onto the wet coating to provide a key or the subsequent coats and achieve a greater dry film thickness. The coating should be applied and finished up to the DPC level. If a plaster or cement ender is to be applied on the bitumen coated surface, clean dry sand shall be broadcasted on to the coating whilst it is still wet. Leave the coating for curing for a minimum period of 48 hours before applying any protection board or backfilling. Care shall be taken to ensure that the first coat is not punctured during the application of the second coat. However, if the coating is damaged, the area can be readily over coated provided the surface preparation is done properly.
PROTECTION
Polycoat RBE coating should be protected from getting damaged due to the ongoing site activities and during backfilling. Coating can be protected either by a cement sand screed (50mm thick) or by an asphaltic protection board (Bituboard*). Alternatively, a 1000 gauge polythene sheet can also be used for protecting the coating in areas where the backfill material is not very coarse
