When the town hires the company to jet the sewer lines, since our house being at the bottom of the system, we end up with both first and second floor toilets overflowing. Not only is the smell daunting and potentially a health hazard, but the water makes its way through the 1st floor ceiling (via the fan) and requires I replace that section of the ceiling (once was ok, 2 times, not so much). I've had many a calls to our department of public works and waste control asking them to notify us so that we can at least drain the toilet (not sure if that would actually do anything), but they do not. A bigger concern is that this happens while one of the kids is sitting on said toilet. Our daughter already had such an experience at the local Ikea (automatic flush that did not go down), and it was not a good outcome.
Now I know we need to call a plumber and install a one-way valve. My questions is:
1) Does that valve have to be installed outside the property, or can it be done inside? Concerned about the cost of digging up the yard, permits, etc.
2) Is such a valve the way to go, or are there better options?
Any suggestions highly appreciated.