To waterproof a new RCC slab, it is best to provide the waterproofing layer directly on the structural slab. The insulation & finishing layers would then come on top.

SECTION THROUGH PARAPET WALL


To obtain a sound waterproofing layer use the following procedure:

  • Clean the surface of all loose particles, dust, cement laitance etc.

  • In case the slab is uneven and undulated it is desirable to make it level and smooth using a thin cement mortar.

  • Moisten the RCC slab (or the levelling mortar) with water.

  • Apply slurry of Polyalk WP and cement in the ratio of 1:1.5 (by weight). The slurry should be freshly prepared. Uniform in consistency and suitable for brushing.

  • After twenty four hours interval apply 2 more coats on the already applied coating.

  • Allow it to set for 48 hours.

  • Cure the coating with wet squeezed gunny bags.

  • Finish the surface as per requirement.


Note: In case the root is a sloping one, then the ‘Polyalk WP’ / cement slurry should be applied over the top of the slab.