Drain Plumbing?

Bought a run-down house. Fixing it up one piece at a time.

Bathroom is tiny. It's on the 2nd floor, and the kitchen is directly below it. I will have 2x8 Joists as the bathroom floor. (Just for dimensional reference)

The first pic below is a crude 3d of the current bathroom setup.

The 2nd pic is a panorama of the current drain plumbing from underneath. (It's a flat wall)

The third pic is the layout we want.

The new shower drain is about 7 feet from the current horizontal run shown in the pic. What I don't know how to do is plumb the shower drain and sink. If I slope it down between the joists, when I get to this horizontal and have to turn 90 degrees left, I'd have to go over the joist. Or, if I go through the joists like it is, I'm afraid I wouldn't have enough slope in the whole thing.

(FYI: I'm double sistering every one of those 2X6 joists with 2X8s. I do know how wrong those are now. The chimney runs through the bathroom, as labeled in 3rd pic, so you know what that is)

Is there a proper way to run the new shower and sink drains? How do I determine if they need their own vent?







Thanks in advance for any help here!

drains

You have a bigger job here than we can help you with. In the first place connecting to a tapped closet bend is not permitted, so you have to make a new connection, assuming you get a permit and inspection. Then the actual routing of the pipes might be an "as you go" thing in order to make the pitch work for everything. You do not have to worry about figuring out if you need vents, because everything needs venting. And I am not sure what is holding the bathroom up after the joists were cut so severly.

VG so far.

motoman

hi. You seem able to express things well, to figure out what is related and what is independent, to be patient with people, and to have all those other good qualities that make a good correspondent so i'll correspond with you. I for one am interested in helping you with this big project ....one thing at a time!

do you believe you understand venting? this is more important than your other questions. You must plan this now, and show this now.

1.) I see a "short" wall, an exterior wall, i guess, and that is where the plumbing is under. Please show how will you get your vents in there.

2.) What material or type of pipe will you be using? Plastic (PVC) or copper?

3.) How far "down the line" will you install new plumbing?

4.) How far away from the exterior wall will you (might you) run the new plumbing?

Strengthening your joists is another topic. Have you considered using plywood or steel? More pictures up close would help me see the problem better.

for the record, i am not expert in plumbing, and i do not know right off the bat what the "right" thing to do is for joists.

the first question is the biggest, and i trust you will post a nice diagram (e.g. a "side view" of the wall). Venting must be in the plans from the beginning.

is the opposite wall available for use to run venting pipes in? would it help to have your drain go through the joists there, under that wall?

david

1.) The short wall is not exterior. On the opposite side of the wall the plumbing runs near is the stairway to get upstairs. So there's no reason I can't run venting right up the shorter wall.

2.) I was planning on PVC, unless there's a reason I should use copper instead for this application?

3.) I was planning to join the existing drain line right about where the copper lines run behind the drain in the 2nd picture.

4.) Not sure if you're asking me if I might move the horizontal run pictured away from the wall, or how far away from that run my longest drain will be?

I know what I'll be doing for the joists. I just wanted to point out that I knew exactly how bad the situation there is. I was thinking that people would say I need to worry about that first, etc. I have considered steel, and plywood, etc.

is the opposite wall available for use to run venting pipes in? would it help to have your drain go through the joists there, under that wall?

Click to expand...

Venting could be run there. But if I ran the drain on that side, the only other drain near there would be for the clothes washer, which is on it's own 2" branch. I was thinking I'd have to go up to 3" pipe then.
But looking now at what I can find on code, it looks to me that a 2" drain line can handle 6 DFUs. The clothes washer would be 3. The sink would be 1, and the shower 2. So if I'm understanding that correctly, I could hook into the existing 2" line that's there now serving only the clothes washer. I think. I have to make sure that's the ONLY thing on that drain line, and that the sink is seperate.

I wasn't planning on pulling permits, but I still want to do it right. Which means I should just cap the existing drain and go the "other way" to a different drain.

But in the mean time, thanx for the input!

run drains to vent first, then out the house

nice response. I got 90% of it.

plan venting first, then send your drains to the vent to pick up that air, and then combine them. When that route is planned you'll find a way to cut the right joists the right way and reinforce them properly too. Copper is smaller than PVC on the outside so you can cut smaller holes. Less noise too, from draining water. i.m.h.o.

before saying more, about other things, i'll wait. Maybe more will be clearer later.

david

Go ahead with whatever else you held back.

I'll get back to you. I'm not sure I completely understand venting requirements. Off to study the plumbing code for my state!