The oldest and the most preferred treatment  is BRICK BATE COBA method:

Cleaning the surface to provide good waterproofing treatment in cement based with Waterproofing compound 'LEAK PROOF'( 1 kg in every 50 kgs of cement bag mixing). On roof the honeycomb` s are grouted first, then a layer of half brick bate is  fixed in uniform level with CM1:4 mixed with ``leak proof`` water proofing chemical, and providing sufficient slope to facilitate easy drainage of rain water.After fixing brick bate the joints of bricks are filled with CM 1:4 with chemical compound, the parapet wall waterproofing plaster comes 9 inches in height in a corce shape with CM 1:4 with chemical compound the top of the brick bate coba applying jointless. Finishing smoothly in CM 1:4 with chemical compound and 300 mm square falls comes on the finishing.(average thickness of the treatment is 110 mm)

cleaning the surface are to provide good waterproofing treatment then providing and laying screed concrete of ratio 1:2:4 admixed with FOSROC CONPLAST X421IC , providing proper slope(1 in 120) for drainage of rain water. Then providing top smooth finishing in CM 1:4 admixed with waterproofing compound, and markingthe surface with 300 x 300 mm false square. 

Cleaning the surface and applying two coats of brush bond / crystalization chemical on the surface

Cleaning and preparing the surface area for carrying out membrane waterproofing treatment , then injection grouting the week areas on the concrete surface with cement slurry & waterpoofing grout. Then Providing and laying APP (Atactic Polypropylene Polymer) modified prefabricated five layer 4mm thick water proofing membrane, black finished reinforced with non- woven polyester matt consisting of a coat of bitumen primer for bitumen membrane @ 0.40 ltr/sqm. by the same membrane manufacturer of density at 25°C, 0.87-0.89 kg/ltr and viscosity 70-160 cps. Over the primer coat the layer of membrane shall be laid using Butane Torch and sealing all joints etc., and preparing the surface complete. The vital physical and chemical parameters of the membrane shall be as under : Joint strength in longitudinal and transverse direction at 23°C as 650/ 450N/ 5cm. Tear strength in longitudinal and transverse direction as 300/ 250N. Softening point of membrane not less than 150°C. Cold flexibility shall be upto -2°C when tested in accordance with ASTM, D - 5147.