I have run in to a problem with my sewer backing up. It is happening about 2 time a year for the last 3 or 4 time i have been able to is a scotchcorp cemical to get clean up the back up this time i have used 2 gallons of the stuff and it is not clean up the problem. I have been read ****** at other sites about how long they should last and we are over 60 years base on the age of my home. I would like to see if any one has replaced the main house sewer and how much they pay? or if any one has any idea on what i can do to get it the water running?