Here is my situation.

About a month and a half ago, I noticed leaking from some baseboards in a room that was in front of the house. This room is in front of all of the pipes for the house. Then in about a week all of the bathrooms started to back up, so I called a plumber and he snaked the pipes from the back end and everything cleared up, including the leaking from the baseboards. This lasted about a week, when everything started to back up again. Strangely the leak from the baseboards didn’t come back. So I called a septic company and they came out and cleaned out the very full septic tank. Everything worked perfectly for about a month. Just last night I noticed the leaking from the same baseboards. I also noticed that the bathtub (that is just in back of the room with the leaking baseboards) was running slowly and when I filled up the tub and let it drain, the leak in the baseboards increased. Do I have some busted main/branch pipes? Can someone please help?

You have several issues going on. Sounds like your septic was more than just full, your field may be bad requiring replacement. The guy who pumped your tank may also be someone who can evaluate the field. When a system is saturated it will backup into the lowest fixture, frequently a bath tube. It should not leak at you baseboards so I'd say you have some cracked or broken drain lines.

The septic guys said the field was fine. The lowest fixture where it backed up to was the shower at the back of the house. What is the easiest/best way to find where the craked or broken drain lines are? If I have to go with a plumber, approximately how much should it cost me? If the main line is bad does the plumber have to go through the foundation or can they go from the side?

First, something is backing up the drainage long before your cracked pipe leaks. You drainage water should flow freely to the septic tank. There is no pressure in an open drain line. I'd have the septic guy take another look if you tank is totally full to overflowing then it is your field in adddition to the cracked pipe. If the tank is not overflowing then your obstruction is before the tank. Your cracked pipes are before the foundation exit. That is why you see water inside the house. You did say the lowest shower shows signs of backing up, right? A plumbers repair will be determined by where the cracks are found. The water leaking at your baseboards is definitely inside the house somewhere. Do you have a basement or crawl space to inspect the drain pipes?

Once the septic tank cleaned out the shower is no longer backing up. I do not have a basement or crawl space. The leak under the baseboards has gone away, so I think it has got to be a roof leak. If I remember correctly, both times I saw the water was when it was raining. I wasn't sure, because of the septic problem that occurred about the same time as the baseboard leaking. I put bleach down the tub and let it sit overnight and poured boiling down the drain. It seems to have worked because the tub drained in about 10 minutes. So next is to call the roofers.

Sounds like you can sit and wait to see if problems return. I would pursue to possible roof leak. You need to find where/how that water is getting inisde. Rot, and worse mildew, will form if this problem continues. Have you ever heard of or done a perk test on your field? A perk test will determine if your field soil can still support a septic system. Even heavy rain should not saturate a field to the point that you get back ups. I have my tank pumped every 3 years, our home owners association requires it every 5 years because we are very near a recreational lake.

What is a perk test? Well it is raining and no leaking from the baseboards, so it may be the top or sidewalls of the pipe that is cracked. Is there an easy way to verify if the pipes are cracked? I would like to find out for sure.

I would open up the wall near the leak. Remove the base board. Identify which wall cavity the drain pipe is in and slice about the bottom foot of drywall down the center of the studs. Remove the screws or drive the nails clear through the drywall. Make a cut from one stud to the other. The leak should be below the height the water backed up in in the shower. There could be a crack running up higher too. How you repair the leak will depend on just what the problem is and what the pipes are made of.

Repairing drywall isn't that big of a problem especially if you have some matching paint left over. Start with a small hole. You can easily make it bigger if you have to. You are going to have to cut a hole to fix the leak.

I would trust the word the sewer people gave you on your drain field unless it backs up again soon. If the field is bad, it will back up as soon as the septic tank refills.