I need help everything is backing up into my shower, from the laundry room to the kitchen. This happened once before and we just used some good liquid draino and it took 2 days to clear, now its been a week and its frustrating, we have to shower elsewhere, anyway, we rented a snake and tried to snake it through the shower except the way the drain curves makes it very difficult for the snake to go through. Do we have to snake through the vent on the roof in order to clear this drain?

Hi Tigers, The following is borrowed from my web site plumbinglessons.com
There are exceptions, but when your drains are all backing up with water it means your main sewer pipe is clogged and water is still entering but not able to go in the intended direction.
In my experience 90% of the time your mainline will back up due to a nonworking clean out next to the street curb.
To properly clean out the main sewer drain you need to have a 3" to 4" cleanout that is readily available. If you don't know where it is, it's probably because it is buried underground like the one pictured above. The best way to deal with it is to have the Plumber locate it with a camera and a location device. After the location is made it's a matter of digging it up and replacing it. Short of that you will most likely come up short. I have heard night mares about Plumbers taking days to find the sewer pipe after digging up 90% of the front and back yards. A sewer camera will reveal what you need to see, and a locating device will pinpoint where it is and how deep it is. Is it a big job? Yes. Is it the best way to go? Bar none. Can you get by without doing it that way? Not unless you want the drains to backup again. Is it guaranteed that once the corrections have been made I will never have a problem again? Pretty much. But it is guaranteed that cleaning roots out of the drain lines only trims them back so they can grow back even thicker the next time.