Clean the surface of the slopping terrace/chajja.
Apply a thick cement slurry over the surface of the slab.
Apply 1 : 1 ½ : 3 metal screen coat.
Cure this coat for at least seven days by putting wet gunny bags on it.
Over this coat, apply a finishing coat with cement sand mortar 1:4 and water-proofing compound as per the design.
Finally, apply the cement slurry with water-proofing compound. Add colour pigments such as red, green etc. as per the requirement for an attractive finish.
Make an edge between the parapet and the sloping slab on the second day.
Cure this water-proofing for fifteen days with wet gunny bags spread over it.
Constant watering is required on a sloping slab.
The perforated pipes are then covered with loose materials like chips and metal to form a filter media.
The size of the filling material goes on decreasing towards the ground level.
How it working?
The underground water finds the way of least resistance through the filter media.
The water is collected in the perforated pipes through the filter media.
Due to the slopes provided, this water is further collected in the chambers in between.
All the water, thus carried away, is finally collected in the deepest chamber or sump.
