Section 102(5) in The Punjab Scheduled Roads and Controlled Areas Restriction of Unregulated Development Rules, 1965
(5)Where the water closet discharges into a soil pipe which also receives the discharge from another water closet, the tap of the water closet shall be ventilated by a pipe, which shall -(a)have an internal diameter of not less than two inches;(b)be connected with the arm of the soil pipe at a point not less than three and not more than twelve inches from the highest part of the trap, on that side of the water seal which is nearer to the soil pipe and in the direction of the now; and(c)either have an open end as high as the top of the soil pipe or be carried into a soil pipe at a point not less than seven feet above highest connection to the soil pipe.
