I'm new to the site but I've already found a few good tips. Thanks all.

Now to my issue(s):

We're almost done digging out our crawlspace to a full basement and have the roughed in plumbing done for a 3/4 bath (toilet, shower, sink) and one bar sink in the new space.

We've roughed in for a sewage ejector pump for the 4 fixtures but now we're at the point where we need to deal with the main sewer line. Currently it's located 1 foot below the top of the foundation which means it ends up at just under waist height when going up the new stairs so it needs to be relocated.

As we weren't sure exactly where the pipe exited the house and down to the city sewer (under the porch slab or in the yard) my plumber suggested routing the new sewer line out into the garage (cutting a chunk out of the garage slab to bury it) then out the front of the house between the driveway and porch, then tying back into the main line. All this would be underground but requires cutting a chunk out of the garage floor. Doing it his way would allow us to keep a "normal" slope (1/4" per foot) on the pipe inside the house.

I did some investigation and found out that the existing line goes straight out 9 feet from the house (past the porch) then has a cleanout and 45 deg. Down angle to meet the city sewer.

My preference would be lower the main line inside the house 3 feet end then run a new line out the front foundation wall and then meet the city line. I've excavated out all around the pipe outside so there's enough room to get to it and put in new joins.

My questions are:

Is it advisable/legal to have a 45 deg downangle drop on the main waste line inside the house so we can drop it 3 feet (to put it under the new stairs) and then exit the house? Or will this cause solids to collect in the main?

Drilling a hole in the foundation should be no problem but what's the best method to excavate the dirt for the new pipe (8-9 feet distance, clay soil under the porch)? I've researched rental places but no-one seems to rent horizontal drilling rigs (only core drills for masonry).

Can I tie the vent pipe for the new fixtures to the vent stack pipe for the toilet on the first floor which then vents to the roof? How many fixtures can be accommodated on one vent stack? I can't see a cheap way to run a new vent pipe from the basement to the roof without taking out quite a bit of wall in the first and second floors.

Thanks for any information and if you need more details, let me know.

Mark

1. Yes, you can install 45 bend in your drain line
2. 9' run is quite a distance to tunnel out under concrete slab. You could buy Hydro-Jet nozzle, attach it to hose and angle-drill, and drill it out.
3. Yes, you can connect your basement vent into your 1st floor toilet vent provided the load is within margins. Connect it no lower then 48" about the 1st floor.

Is it advisable/legal to have a 45 deg downangle drop on the main waste line inside the house so we can drop it 3 feet (to put it under the new stairs) and then exit the house? Or will this cause solids to collect in the main?
No problem! We 45 down all the time when we connect the house sewer to the cities street raiser.

Drilling a hole in the foundation should be no problem but what's the best method to excavate the dirt for the new pipe (8-9 feet distance, clay soil under the porch)? I've researched rental places but no-one seems to rent horizontal drilling rigs (only core drills for masonry). You can make your own jet using a pressure washer and jet the pipe in.

Can I tie the vent pipe for the new fixtures to the vent stack pipe for the toilet on the first floor which then vents to the roof? How many fixtures can be accommodated on one vent stack? I can't see a cheap way to run a new vent pipe from the basement to the roof without taking out quite a bit of wall in the first and second floors.
You ask? "How many fixtures can be accomodated on one vent stack?" We don't go by fixtures. We go by fixture units. Your basement fixtures total 7 fixture units plus the upstairs toilet equals 11 fixture units. A 2" vent accommodates 12 fixture units so a 2" fixture vent's acceptable. But wait! You haven't even addressed the ejector pit vent which MUST be a separate dedicated vent out the roof. This vent can not be combined with the house vent. If you can't run it out the roof can you take it outside up the wall? Let me know, Tom

No problem! We 45 down all the time when we connect the house sewer to the cities street raiser.
You can make your own jet using a pressure washer and jet the pipe in.

You ask? "How many fixtures can be accomodated on one vent stack?" We don't go by fixtures. We go by fixture units. Your basement fixtures total 7 fixture units plus the upstairs toilet equals 11 fixture units. A 2" vent accommodates 12 fixture units so a 2" fixture vent's acceptable. But wait!! You haven't even addressed the ejector pit vent which MUST be a separate dedicated vent out the roof. This vent can not be combined with the house vent. If you can't run it out the roof can you take it outside up the wall? Let me know, Tom

Speedball,
Thanks for the quick response! I'll be heading to city hall tomorrow to verify with the inspector my plan will work but this gives me more confidence.

Regarding making my own jet, how exactly would that work? I've got a pressure washer so would I just core out the masonry hole, pressure wash out the soil as I move the new pipe into position? I've got limited front-to back clearance where the stairs are routed so I'll most likely need to use multiple pipe segments and join them as I core out under the porch.

For the ejector pump, I could route the pipe through the small remaining crawlspace and then out the back of the house and then to the roof. I'll need to evaluate the aesthetic options of that decision versus something more drastic.

Thanks,

Mark