[masraum]

Originally Posted by 908/930

That is what I was picturing, was just thinking that if there is a clear path right beside that beam you could just go around it. Another possibility would be supporting the joists and replacing that wood with a steel I beam with the clearance hole cut into it. I would trust the steel over the wood with a large hole in it. You are going to add a vent to that pipe? If you intend to fully support under the 4x6 with a wall that should be fine.

the big beam is perpendicular to all of the floor joists. To go around it, I'd have to go through a joist twice.

Originally Posted by look 171

Hosw big is that span and how thick are the floor joist?

floor joists are 2x6 and the span is 9'

Originally Posted by 908/930

You mention 2x6 joist, something to consider is a 4" long elbow is about 8" to the bottom then add your slope.

We discussed with the plumber putting the toilet on a small platform to raise it up high enough for the pipe to run within the space within the floor. Then we are going to drop the ceiling in one room by ~6" to ensure that there's enough space for the 1/4" to 1' drop.

Originally Posted by Crowbob

If there's no concrete and rebar involved you should be OK.

Nope, all wood.

Originally Posted by dad911

Is there a reason you cannot just drop a new drain line through a different 1st floor wall?

I'm pretty sure that would be a much bigger job. The reason that it works for the existing drain line is because it drops down under the stairs.

Originally Posted by rwest

Air admittance valve may not meet code in your area; might want to check first.

The plumber seems to think it is, but I'll confirm. If not, there's place for us to get a regular vent installed.

Thanks everyone.