Main 3" Stack Location

Hello!

I'm in the process of building a new home. I have taken on small plumbing jobs but never a complete project. The bids on this project came in higher then expected and I have decided to tackle the project on my own. I have a question regarding the location of the main stack. The hole has been dug and the excavator brought the main sewer lateral into a bedroom area. I would like to extend the main drain line further into the home and make a sweeping 90 toward the mechanical room. I wanted to make sure that the main drain can make a sweeping 90 under the basement floor before connecting to the main stack. All books I have checked out at the library show the main line coming in and connecting to the stack without any bends under the basement floor. Furthermore, can a 3" main stack be brought through a load bearing 2x4 wall?

Regards,

EGavin

If you do turn it 90 degrees put a cleanout at the bend (well, not at the bend - extend the line an extra 24" past your turn then put a cleanout). It's good practice to go straight to the main stack but there isn't anything codewise prohibitting it.

A 3" pipe does not fit in a 4" wall. 3" is I.D., O.D. can be ~3-1/2", then at the fittings its even bigger. Some plumbers may tell you it will fit but the wall should be a 6" wall.

I will attempt to disuade you, you are taking on a project that you may one day wish you had never started. I know it may seem easy, cut and glue pipe, how hard can that be, right, but everywhere I know of you have to submit mechanical drawings and there is just far more to it than you think, know, and understand. Most places charge for reinspections of mistakes you make. It may take you 10-20 times longer to do than it would a plumber. I would suggest you work overtime at what ever job you do and let a plumber do it. You will be much happier when it is over.

stack

There are several things that you can always depend on regarding a construction project.
1. The bids will always be higher than you estimated they would be.
2. The final price of the building will always be more than the sum of the original bids.
3. If you do it yourself, the job may still cost more than your estimate, and you may not have a workable installation.