Basement floor drain and toilet issues - need help pls!

Hi - I am hoping someone can point me in the right direction on some plumbing issues I am having recently. A couple of nights ago the floor drain in our basement backed up when I was running the washing machine. A second "test" of the problem revealed that the back-up would start about a 5 second count after the washing machine had emptied itself into the laundry sink. In addition, a couple of days ago I installed a low-flush toilet in a completely renovated bathroom I just finished in the same basement. I have noticed the toilet has problems flushing and will "cough" up large airbubbles. My first thought was "dammit, these low flush are useless" but then when the drain started backing up as well when running the washer I started to suspect the two are related. I remember reading somewhere that "coughing" toilets are a problem with ventilation, but I have a hard time believing that my vent pipe (located on the roof) could be blocked. Anyone have any thoughts on all of this? I would really appreciate it!

Phil.

It sounds like you have a blockage in the main line. either within your home or, going out to the street. It sounds like it is partial at this point but it will become worse I assure you. Blockages often cause flooding in the drain pipes and mimick vent problems because the vents become flooded and stop working effectively.

You need to call in a pro that cleans drains.