On Thursday, January 14, 2016 at 4:55:13 PM UTC-5, Don Y wrote:
On 1/14/2016 2:44 PM, TomR wrote:

But, like you, I think that if I used the pressure approach the issue of
trying to get the overflow plugged, plus the question of whether the
pressure would make the slip joints in the sink trap come apart, made me
hesitant to try it.

Then I thought, what if I took apart the sink trap, and I installed the
expandable pressure piece directly into the sink drain line, would that
work? I haven't tried it yet, but maybe that would be an option.

You still have the vent up to the roof to contend with. The pressure
solutions really only work to dislodge "dislodgeable" obstructions :
I find them preferable to resorting to chemicals as those are easily
overused.

But, if someone has made a special effort to clog your drain
(e.g., roots infiltrating the sewer line), no amount of pressure is
going to help. (a motorized snake with cutting head for root
problems)


ahh to clear tree roots just mix rock salt or softener salt in very hot water, and that kills tree roots fast, but doesnt harm the trees