DIY replacement of a section of sewer main
 

I have an issue with a main line of galvanized pipe the is sagging and things aren't draining properly. I got a quote from R.R. for 4k. To put in a 30 foot section of schedule 40 PVC. The pipe by the house is ok and the last 12' to the city are good. So it sounds like I just need to drop in a section that to maintain angle.

I am a pretty advanced DIYer. I am thinking I could do it for less than half if I did it my self. I could rent a back hoe and dig the hole (about 4 - 5') down. Drop in 30' of PVC with collars on the galvanized. I am not afraid of the work but I'm wondering if I'm missing something.

If you really have a galvanized sewer pipe it's going to be sooner then later that it starts to rust through allowing roots and dirt into the pipe not to mention constricting from the rust buildup. Even if you have cast or ceramic it makes much more sense to just do the whole line while you have half of it exposed anyway.

If you're a proficient backhoe operator and you know how to properly slope the line and make the transitions then you shouldn't have any trouble.

But even if you're a proficient backhoe operator it's still usually cheaper to just hire someone by the hour with a backhoe to do the dirt work. I also agree with doing the whole line at once and don't forget to get necessary permits.

On a recent residental sewer line replacement of about forty feet we found in addition to the locator marked water, phone, and power lines, another forgotten water line, two heating oil supply lines from a forgotten underground tank and big surprise, an unmarked gas line. Be careful when you dig.