Hi,
We own a fairly old building and the apartments have shared plumbing of the kitchen sinks, when one has a clog it effects the apartment across the hall causing backup and they both have to be snaked to clear the clog, is there any regular maintenance that we can do to avoid this.
Thanks

Probably not, although if you have a garbage disposer, filling the sink with hot water and then running the disposer as it drains would help prevent buildup in the pipes.

i disagree. fill the sink with cold water not hot. the cold will congeal any fat so the disposer can grind it up. hot will liquify the fat only to congeal in the pipes.

WE are talking about TWO DIFFERENT things. IN the disposer, cold water congeals the grease so it can be "ground up"> In the pipes, the hot water will emulsify the grease and the pumping action of the disposer will help push it down the pipe.

The regular use of an enzyme based preventative drain cleaner will help, but it can only slow the problem. The drain pipe material, how it was installed, and what is being put down the drain will have the most effect. An enzyme cleaner will help control soap and grease buildup only, it won't help if someone dumps trash down the disposal.

Enzyeme Drip, with automatic dispensers are used in some of the tallest commercial building in North America. These are building that have shared commercial users, residential apartments, condos and restaurants. The enzyeme drips protect by coating the main sewer line that drain lines flow into. Enzyemes are good for organic influences, not solid debris.

Much depends on those who reside in your building. When they are abusive, all will suffer.
How many residents in your apartment building?

Best Wishes