First the plumbing scematics: I have a cast iron sewer line that runs from a hall bathroom, in my crawl space, to the City's line. The kitchen sink and dishwasher tie into this line also. A master bathroom and laudry room were added to the house (prior to me purchasing). The master bath and laundry room drains meet up and then connect to the main cast iron pipe before it leaves under the house.
Now the problem: A few months ago, the master bathtub and toilet started bubbling up. The other half of the house was draining fine, but when you put water into the working side, it bubbled in the master bath. The only clean-out is under the house, between the master bath and where it connects to the cast iron. I tried hand-snaking the line and couldn't get it.
I called a plumber and since I have no clean out, outside the house, he pulled the toilet and snaked it from the master bath. He hit a clog and worked it until it appeared to break and he could get more snake into the line. At that point, though past whatever it was that he had originally hit, it was still bubbling when the other bathroom was flushed. He continued to push the snake into the pipe until the bubbling stopped and the master bath drained well. When he pulled the line out, he brought up roots. He recommended that I replace the sewer line between the house and the street, as roots are normal for older houses, reset the toilet, cleaned up and went on his way.
About 2 weeks later, the problem started again. Half the house drains properly, but the master bath bubbles up. To me, this sounds like there is a clog between where the two halves meet, not out in the yard. Does this sound right? I realize that at some point I will probably have to replace the line under my front yard, but I don't think this is the cause. This would mean root are growing up the main cast iron pipe (where both flow, about 15 feet long) and into just the one pipe being fed from the master bath. This logic would mean that only half the house was effected by the roots.
The third-party issue here is that I have a home warranty (never again) and they will not cover any plumbing if roots are found in the line - regardless if it doesn't appear to have anything to do with the issue at hand.
What's the next step here? I am being quoted about $2700 for the replacement, but if I'm right, this will not fix the problem anyway. Correct? Also, should they be liable for the problem that was not fixed in the first place?