Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-07-2011, 10:25 PM   #1
Newbie
 
Join Date: Jul 2011
Posts: 2
Share |
Default

Plumbing mystery


The previous owners of my house dropped the ceiling in my kitchen to accommodate plumbing for an upstairs bathroom. I'm in the process of remodeling my kitchen and am planning on running the waste and supply lines through the joists in order to restore the ceiling to its original height.

I'm trying to make sense of the way the waste lines are currently set up -- see the attached pic. The line from the sink runs diagonally for 5 ft before joining up with the main waste arm. Why do this, rather than run a much shorter arm perpendicular and into the waste arm (see blue line)?

For context, the picture is taken from below looking up at the kitchen ceiling.

Thanks
Attached Thumbnails
Plumbing mystery-kitchen_plumbing.jpg  


Last edited by iconnary; 07-07-2011 at 10:27 PM.
iconnary is offline   Reply With Quote
Old 07-07-2011, 10:33 PM   #2
Member
 
Join Date: Aug 2010
Posts: 1,526
Default

Plumbing mystery


Could be because the entire run is vented by one vent and the rest is wet vented, therefore the toilet has to be the last to drain to the line before the stack.

You might want to re-think drilling the joists with the drains running like that. Any mistakes and you could affect their integrity.

VIPlumber is offline   Reply With Quote
Old 07-07-2011, 10:44 PM   #3
Doing it myself
 
Alan's Avatar
 
Join Date: Apr 2006
Location: Crescent City, CA
Posts: 3,744
Send a message via AIM to Alan Send a message via MSN to Alan
Default

Plumbing mystery


Quote:
Originally Posted by VIPlumber View Post
Could be because the entire run is vented by one vent and the rest is wet vented, therefore the toilet has to be the last to drain to the line before the stack.

You might want to re-think drilling the joists with the drains running like that. Any mistakes and you could affect their integrity.

I second ALL of this. What size are the joists? I'm assuming they are dimensional lumber?

There are only certain places you can drill dimensional lumber. There is a reason they ran it below the joists. Your other option is to completely replumb the underside of your house as well and get it to where your drains run parallel with the joists. How low is the ceiling?
__________________
Journeyman Plumber
Alan is offline   Reply With Quote
Old 07-07-2011, 11:28 PM   #4
Newbie
 
Join Date: Jul 2011
Posts: 2
Default

Plumbing mystery


The joists are dimensional lumber, 2x10 (9.25"). My reading tells me that I can put holes no larger than 25% of the depth through the centerline of the joist. That gives me 2.3" max diameter holes I can put through the joists, which ought to accommodate 2" waste line for bath and sink. The toilet line is 3" but will only need to run through two joists, one of which is sistered, as will the other be.

As for venting, so far as I can tell the main waste line shown in the pic isn't vented itself, but rather goes straight into the house's main vertical sewer line. The main sewer line is vented. This seems contrary to my understanding of when/where venting is needed, but we've never had any issues with the plumbing setup as is.
iconnary is offline   Reply With Quote
Old 07-08-2011, 09:25 AM   #5
Doing it myself
 
Alan's Avatar
 
Join Date: Apr 2006
Location: Crescent City, CA
Posts: 3,744
Send a message via AIM to Alan Send a message via MSN to Alan
Default

Plumbing mystery


Quote:
Originally Posted by iconnary View Post
The joists are dimensional lumber, 2x10 (9.25"). My reading tells me that I can put holes no larger than 25% of the depth through the centerline of the joist. That gives me 2.3" max diameter holes I can put through the joists, which ought to accommodate 2" waste line for bath and sink. The toilet line is 3" but will only need to run through two joists, one of which is sistered, as will the other be.

As for venting, so far as I can tell the main waste line shown in the pic isn't vented itself, but rather goes straight into the house's main vertical sewer line. The main sewer line is vented. This seems contrary to my understanding of when/where venting is needed, but we've never had any issues with the plumbing setup as is.
You usually will need a hole about 2-9/16 for 2" which is greater than 2.3" .

There's also the issue of maintaining grade if you have to drill on the centerline of the joist.
__________________
Journeyman Plumber
Alan is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dishwasher plumbing mystery Handy Cathi Plumbing 3 07-01-2011 09:19 PM
ALOT Of Help Needed for Plumbing ~FYE~ Plumbing 4 09-22-2009 12:28 AM
Sewer smell after hooking into plumbing vent daveyd Plumbing 10 08-10-2009 06:25 PM
can anyone identify this mystery basement plumbing??? pkovo Plumbing 6 03-08-2009 10:20 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.