I purchased a 1930 home several years ago. About once per month there is a back up of sewage in the floor drains (one is inside and one about 2 feet apart, but outside. There is no clean out, but the previous owners (now deceased) had a hole cut in one of the main sewage lines coming from a second story bath. I clean it out and then one month later, have to do it again. I never bring anything out with the snake, which I take 30-40 feet out. The main line under the street should be only 25 feet away. If I install one way values, I assume the sewage will head up the pipes into the upstais bathrooms, or into a third floor drain, which drains the down sloping driveway before the water enters the house, and it also drains the downspouts from the roof. What is best solution to this problem without digging up the pipes?
