What is the best way to clear cast iron drain pipes as a step towards making future preventive maintenance cost effective and less labor intense? Is there a preferred cutter to use on a rooter machine that could accomplish this? Is there chemicals that are safe to use that can assist the process. I am working at an apartment complex in the maintenance department and I have experience clearing drains. The manager ask me the other day about what I've ask in my question. He wants to spend the money and time to do this and I like to be able to do it right. Thanks John

Not a plumbing expert, but this is what I've heard over time...

I've been told to flush waste and vent systems with a garden hose each spring and fall, though I've not followed this advice myself.

Also my father in law regularly put some chemical tretment for roots down the drain once a year... I think he used the same chemicals that they use for algae treatments in pools... copper sulfate I think. After having his lines mechanically augered, he used this to treat for roots every year.

Hi John,

"Is there a preferred cutter to use on a rooter machine that could accomplish this?"
For pipes 3" and up we use a Ridgid K-60 sewer machine. For pipes 2" andunder we use a Ridgid K-50 machinhe. I also carry a 1/4" hand held snake to clear lavatory drain lines inside walls.
For outsides sewer lines that have a root problem we use a K-60 with a cutter tip. To control roots after you finish call around to garden supply stores and ask for fine grain Copper Sulphate. Put a 1/2 pound in your toilet and flush it down. Repeat in 6 months.
For inhouse blockage we use a auger tip.

"Is there chemicals that are safe to use that can assist the process?"
I'm no fan of putting harsh chemicals down your drainage. Besides, they only seem to work in TV commercials. The only sure way to remove a blockage is with a snake. Regards, Tom