Quote Originally Posted by Archerfish View Post

Going back, economically speaking, or rather in a profitable manner, why should a contractor spend more by installing a larger sized pipe when a small and cheaper one will do for the next five years? If it leaks, then the said contractor is no longer liable as it is beyond the warranty period.
going back,
"oversize that drain! insist on it!"
personally, i would insist on at least double the inner diameter.
and i would insist on effective gravity stimulus in its installation.