Hi, I'm writing because I am getting conflicting answers and before I spend money to fix this problem I'd like to know the correct way to do it.

Here's the situation. We bought this house in July of 2007. It was built in the 1940's. It is connected to the city sewer system. Plumbing was fine. In December of 2007 we had someone install a 3/4 bath and a utility sink in the basement. Just a couple of weeks after the work was completed the toilet down there stated making belching type sounds. Then the shower down there backed up a few times with water, gravel, and dirt when I took a shower upstairs. Then I noticed that what looked like dried toilet paper was around the grate in my driveway. And then I noticed after doing a couple of loads of laundry that water started coming up from the drain in the basement (that the hose from their conditioning unit drains into). The basement drain now overflows when I take a shower upstairs or do laundry. I'm not sure if it is still doing anything outside as I haven't thought to look and have been trying to REALLY limit my water consumption until this is fixed. By the way, there is no smell with the backed up water. I don't know if it is a coincidence that it started backing up shortly after the basement work was completed or if the guy did something wrong ar a bad job or what.

When I spoke to the guy that did the work, he told me that it was my toilet paper causing the problem and to NOT put any toilet paper in any of the toilets ever. I thought that was ridiculous and still do, I mean come on. He also said that it is or could be because of the drain in the driveway being clogged from mud and such. But we've had heavy rains in the past couple of days and no water collected in my backyard so I guess that drain is working okay. Anyway, he insists that the problem is toilet paper and or mud in my outside drain and that the drain needs to be snaked from the basement drain and that will fix it.

After hearing the toilet paper thing, I decided to ask someone else. Granted, this is just over the phone but the other guy said that first, NO toilet paper should be coming from the drain outside. That it is a storm drain and has nothing to do with the drainage system from the house and if toilet paper is coming up from it, then the guy that did the work most likely tapped into the wrong system and has the drainage from the house going into the storm drain system, which is very bad and a big deal to fix (break up concrete floor again, and so on). He also said that the guy must not have vented it and that is why the toilet is burping, because it is trying to get air anyway it can. (I vaguely remember having the inspector say the same thing about it not being vented and that it could cause problems down the road). New guy said that the guy that did the work must have just hooked everything up to the existing system and that it was only meant to withstand the fixtures that were already in the house. He said the other guy did it the easy way and not the right way. His fix is to first check the roof vent and make sure that it isn't clogged by a nest or animal carcass. Then he wants to snake the line (I don't recall if he said from where), but I think he was talking about doing it from the basement. He said that snaking it might fix it but that I would have the same problem after a couple of weeks. He said he would snake it basically to appease the first guy, but he thinks ultimately the first guy needs to redo what he did wrong in the first place because that is the problem.

I'm sorry this is so long, but I could really use some help. Thanks in advance.