Surface Preparation

The old waterproofing system must be examined for its soundness. The cementitious treatments like Brick Bat Coba with smooth IPS finish shall be examined for the cracks, hollowness and undulations. The slope shall be checked for effective drainage of rainwater. The hollow Brick Bat Coba portions shall be carefully removed by chipping to its entire depth and redone after profiling it to a rectangular or square shape. The surface cracks shall be filled with cementitious crack filling compound from the Dr. Fixit Range, Dr. Fixit Crack-X powder as per the specifications. The wider cracks beyond 5 mm shall be filled with Polymer Modified Mortar using Dr. Fixit Pidicrete URP. In case of top 20 mm thick IPS of existing coba is bad and needs removal, the same shall be carefully removed and redone with Polymer Modified Mortar using Dr. Fixit Pidicrete URP. For this, add Dr. Fixit Pidicrete URP at the rate of 6 to 8 % by the weight of cement to 1: 3 cement sand mortar. All the repaired surfaces shall be cured in accordance with the materials requirements. The repaired Brick Bat Coba shall be cured for a minimum of 15 days while; IPS laid with Polymer Modified Mortar shall be cured for 3 days with wet hessain, and not by water ponding. For other surfaces like clay tiles or any other tiles, china mosaic tiles, etc., the surface shall be checked for its firmness with the substrate. The joint between the tiles shall be filled with tile grout or polymer modified mortar. Loose tiles shall be re-fixed firmly. The china mosaic surface shall be grinded with the suitable grinding machine to ensure mechanical key with the coating. All water pipelines, gas lines or any other service lines, touching the top surface of the slab, shall be lifted up and properly supported by suitable support system. Finally, the surfaces to be applied upon, must be clean, reasonably dry, free from dirt and loose material, and conform to the agreed minimum surface standards. Newcoat shall not be applied on the bitumen-based systems like Tarfelt or similar membranes.

Primer Application

Pre wet the surface prior to application of primer and allow surface water to evaporate. Apply water-based primer Dr. Fixit Primeseal (diluted with water in the ratio 2:1) on the cleaned surface @ 12 to 15 sq m/ltr. The priming will enhance the adhesion of the membrane to the substrate and will block the surface pores. Allow the primer coat to dry. The drying will generally depend on the ambient temperature.

Newcoat Application

Apply 1st coat of Newcoat on the dried primer coat uniformly with stiff nylon brush / roller at the rate of 2 sqm/ltr. Apply 2nd and 3rd coat at the same rate after drying of the previous coat. Choose any two or all the three available colour for the 3 coats. This will ensure the correct application of the material and the supervisor can have a proper control over the application. For uniform and fast application use of roller is highly recommended. Newcoat shall be applied directly from the pack without diluting it for all the 3 coats. The drying time for each coat depends on the ambient temperature and can vary from place to place. At 30 degree C, the coat will be dry up within 4 to 5 hour. All the concrete / masonry pedestals present on the roof, constructed for supporting the water tanks or pipe lines or dish antenna, etc., also should be coated with Newcoat along with the terrace. The junction between such pedestals and the slab shall have corner fillet (corner roundings) made from Polymer Modified Mortar. For this Dr. Fixit Pidicrete URP from the Dr. Fixit range of products can be used.

Cementitious Substrate	Application of Dr. Fixit Primeseal
Application of 1st coat of Dr. FixitNewcoat	Roller Application of Dr. Fixit Newcoat	Application of 2nd coat of Dr. Fixit Newcoat
Application of 3rd of Dr. Fixit Newcoat

Parapet walls

The Newcoat application must continue over the parapet wall up to the top. If desired, one can terminate the coating at 300 mm height on the vertical face of a parapet wall at the drip mould, made in plaster. In absence of any such water mould, the coating shall be extended till top of parapet wall. All rain water pipe 'openings' shall be coated with Newcoat from inside to a distance of 2 inches.

Termination At Expansion Joints

In the case of large roofs with an expansion joints, the Newcoat application should be terminated at the joint. A curb wall of 4 inches thick shall be constructed on both sides of joint, which may be from 150 mm to 200 mm in height The curb wall shall be plastered smoothly and corner rounding with polymer-modified mortar shall be done before Newcoat applications starts. The joint shall be covered either with GI strip fixed on one of the curb walls while leaving other end free or by neoprene sheet (as detailed in the sketch) The expansion joint shall be filled with 2 part flexible Polysulphide Sealant from the Dr. Fixit Range in accordance with the product specifications.