All, TIA for advice. I work in a 6 floor apartment building and we're doing a routine maintenance snake of the tiers of kitchen drains. The plumbing company is suggesting they need to snake every unit on every floor, but I would think they would only need access to each of the top floor units and can snake the whole tier from there (and thus not need access to all the lower units that feed the same drain lines). Is the plumber correct for some reason I'm not considering or is he simply trying to bill me to needlessly snake every unit? Also, if the drains are all one and quarter inch pipe, is that the size of snake that'd ideal be used? I believe they're suggesting the use of a three quarter inch snake, which seems undersized. Again, I'm concerned they might just be trying to use a three quarter so we have to use them again sooner and shell out for the job again. Finally, how often would everyone recommend we have the snaking done? Every year? Every 3? Every 5? In summary - do we need to snake every unit, how often, and what size snake. Thanks for the advice.