My basement drain is blocked just above the t-joint that goes out to the
street with leftover cement that was used as a mortar for z-brick that
the previuos owner had put in the kitchen area. The drain goes down
approximately 20 inches to where the t-pipe is located. I plan on taking
a large drill bit welded to an extended shaft to try and drill out the cement.
About how far down can I safely drill before drilling through the bottom of
the drain pipe itself?? The house is a single story ranch about 33 years
old. Any advise would be greatly appreciated.

Thanks,

Karl Dorfner