Select well burnt (pucca) brickbats. Use of overburnt brickbats should be strictly avoided.
Before laying brickbats, soak thoroughly in water for at least half an hour.
Lay the well burnt (pucca) brickbat on the edge (kadi) and not on a flat surface.
Any gaps between the brickbats should be filled with mortar. Complete the brickbat coba coat with joints filled with cement mortar in 1:6 proportion. Also use water-proofing compound as per the specified dose per bag of cement while filling the joint.
Give the slope of 1:100 in brickbat coba coat from the entrance door to the water escape pipe.
All the holes made in the wall for P.V.C./C.I. pipe connections should be finished with water-proofing coba along with this coat.
Cure this coat by ponding water for four days and check for any leakages.
Topping coat for w.c. water-proofing
After curing of the brick bat coba coat, complete the
topping coat with 1:4 cement-mortar mixed with water-proofing compound (as per
the given bag ratio in literature of product). Finish this coat properly with
neat cement slurry by metal float (thappi).
Roughen the surface with a wire brush, for bonding of
the horizontal filler coat. Continue this coat on the side walls, upto 45cm (18”)
above w.c. floor level. This coat should not project out beyond the plastering
coat of the w.c. walls so as to avoid unnecessary thickness of the glazed title
dado.
Curing this final coat for a minimum of seven days,
with water upto minimum 7.5cm (3”) depth.
