I live in a 1960's mobile home.
Occasionally our toilet would back up into the bathtub or just overflow. The tub and kitchen sink drains have been running slow for the last year or so. The problems always seemed to correct themselves after some plunging, but would come back in a couple months.
A few days ago the toilet overflowed and backed up into the bathtub. I got on the roof and ran water down the 2 vent pipes above the bathroom. This shot some leaves and dirt up into the toilet and bathtub, but did not cause them to drain. After a couple hours everything suddenly drained, I assume due to the weight of the water over time.
I bought and have used some enzyme drain cleaner, since I'm a little wary of using anything acidic on such old pipes. Nothing really improved.
Today I decided to check the 3rd vent pipe above the kitchen. I climbed up and started pouring water in. It filled up to the top after about 1/2 gallon. I pushed a broom handle down and encountered a fairly solid spongy mass that took some good pushing to break down. Hopefully not a dead rat or something...
Now the sink drains fine, and the tub and toilet appear ok(only time will tell).
Is it possible that the single vent pipe in the kitchen caused problems in the bathroom? Am I in the clear now? Do enzyme drain cleaners do any good?