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DangerMouse 07-25-2010 01:02 PM

More drain size questions
Is 1½" drain pipe (pvc) OK to use for my drains and vent pipe?



Mike Swearingen 07-25-2010 01:03 PM

Yes, but for sinks only mainly.

DangerMouse 07-25-2010 01:06 PM

Kitchen sink, 2 bathroom sinks and a shower/tub.
4" for 2 toilets and vent to the roof, unless smaller is ok?


Proby 07-25-2010 01:39 PM

From my reading I found that:

1 1/4" is for bathroom sinks.
1 1/2" is for kitchen sinks and bathtubs
2" is for stall showers

DangerMouse 07-26-2010 10:59 AM

1 Attachment(s)
Oh-kayyyy, I think I'm getting closer.... Po)
Thanks to all who have been so patient with me thus far!
Here's what I have put together to do the soil and venting so far.
The 4" vent pipe through the roof will pass through a 6" wall of the bathroom.
(I dislike soffitted-in stacks in corners.)
I'm thinking the inspector will have no problems with this setup.
All 2" drains and vents for fixtures. Proper pitch from point "A" to point "B", etc.
I'm looking at an old book on plumbing I have and it says "Vent pipes extend through the roof and, where there is any danger of frost, should be at least 3" in diameter." (©Mechanix Illustrated, 1961) and we DO get kinda cold here, sooooo I figure I'll just use up these 4" tubes! Better safe than sorry!

Thanks again


DangerMouse 07-26-2010 11:09 AM

Oops.... there's a piece missing, under the beige piece under the toilet, before the elbow will be a 4"X4" to 2" same as the one on the vent for the 3 drains to flow into.
I just got the wrong size and need to exchange the one I have.
(we all make misteaks)


DangerMouse 07-26-2010 12:52 PM

Starting at the kitchen sink....
1 Attachment(s)
This is what I'm looking at doing to begin the drain/vent run.
Anything wrong? Not in use or glued yet.



jogr 07-26-2010 06:39 PM

You want to eliminate the s trap that will suck dry. The p trap should go into a a sanitary t with the vent being the leg of the T going straight up and the drain going straight down.

DangerMouse 07-26-2010 07:35 PM

Got it.... Thank you. I thought it didn't feel right yet.... lol
Piece by piece, I'll get this done......right.


TheEplumber 07-27-2010 12:02 AM

199 Attachment(s)
Consider increasing the drain line to 2" also

DangerMouse 07-27-2010 07:25 AM

The end of the drain line, under the crawl space is 2". I'll be using 1½" for kitchen sink and bathroom sink(s). Then 2" for the tub and final run of sink drains and vents. I have 40' of 2" pipe laying around so I'm still hoping I can vent through the roof with THAT instead of the 4". If this is ok by code, then I'll lay things out accordingly, shoot a pic and hope everyone here approves! Once I have an OK from all the great guys here, I'll call the plumbing inspector to come out and approve it, then start gluing and putting it together. We can't be without water/toilet for more than a half a day so I need to be certain it's ready for the guy to OK.

Thanks to all who are helping us through this *frustrating* time!


DangerMouse 07-27-2010 08:26 AM

1 Attachment(s)
OK, here's how the undersink pipes are now.
THIS is the correct way, yes?



DangerMouse 07-27-2010 08:38 AM

This site shows a 2" vent AND a 4" soil stack vent through the roof....
*confused again....* Can I just vent with the 2"?
2 toilets (maybe just one) 1 tub and 3 (or 2) sinks?

*sigh* I'll figure this out yet!


rjniles 07-27-2010 08:42 AM


Originally Posted by DangerMouse (Post 475967)
OK, here's how the undersink pipes are now.
THIS is the correct way, yes?



You are kidding about this, aren't you:wink:

DangerMouse 07-27-2010 08:49 AM

Oh great.... Now I read this.... "We show white PVC plastic, type “Schedule 40,” but some regions may require black ABS plastic. Use the specified glue to cement each type." This setup HAD black sch40 vent piping. How do I know if my region requires it WITHOUT bothering the plumbing inspector? I'm all set up to use pvc, but if I have to plan on black ABS, I have some.... just need to be sure before laying everything out. Personally, I don't see a difference, it's just for air, right? But I have to be certain.



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