DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Plumbing Forum > Moving kitchen sink - how far can vent lines travel?

Thread Tools Search this Thread Display Modes
Old 04-14-2008, 04:43 PM  
Junior Member
Join Date: Apr 2008
Posts: 9
Default Moving kitchen sink - how far can vent lines travel?

I need to move my kitchen sink (and dishwasher and disposal) to an outside wall. I determined I have enough room to provide a 1/4" downward slope per foot the drain travels. The supply seems simple enough. I understand I need to insulate pipes on the outside wall.

I do not know what is required in moving the vent lines. Can they go horizontal 11 feet including around a corner? Even if I put a new roof vent above the new location, I can't vent straight up because it will be in front of a window. One suggestion I got was to use the mushroomy thing used in trailers but I fear that might stink (and is illegal?)

Thanks for your help.

Amber is offline  
Reply With Quote
Old 04-14-2008, 09:49 PM  
Senior Member
Join Date: Mar 2006
Posts: 2,990
Liked 3 Times on 3 Posts

Send a message via AIM to glennjanie

Hello Amber:
Plumbing codes are different in each state but your 11' vent will be much b3etter than none at all. The only problem is, it sounds like you will be running this vent inside the cabinets, whereas a vent is not supposed to go horizontal until it is 6" above the flood rim of the highest fixture on that floor; and the vent should run in an uphill grade to provide for drainage of condensation in the pipe.
It may be possible to run the drain 3' or so to the side of the sink, then run the vent up through the roof and the drain down through the floor at that point. Of course, each penetration of the roof is another potential leak, so the vent could be run up to above the top plate then across to the main vent. The vent can be run up to 25' in this manner. This could be much more comfortable to run than draining through the cabinets.

glennjanie is offline  
Reply With Quote
Old 04-15-2008, 09:28 AM  
Senior Member
Join Date: Sep 2006
Location: Lafe Arkansas, Arkansas
Posts: 165

That "mushroomy" thing is called an Air Admittance Valve and they are normally used for island sinks in all types of homes (not just trailers). They are a one-way valve that allows air in to facilitate drainage. Most, but not all, areas allow them. You would need to check Local Codes. Studor is one brand I am aware of and have used in many new construction homes.
if you have never made a mistake, you probably haven't done much.
majakdragon is offline  
Reply With Quote
Old 04-15-2008, 11:34 PM  
Senior Member
Join Date: Mar 2006
Posts: 2,990
Liked 3 Times on 3 Posts

Send a message via AIM to glennjanie

My experience with air admittance valves: they use a small spring to close the valve when there is a positive pressure in the drain-waste-vent system, and the spring allows the valve to open when there is a negative pressure or vacum in the system. In the process of draining the kitchen sink you may have pressure and vacum at different times; sometimes alternating up to three times. Sewer systems have alternate acidic and caustic liquids and sometimes gasses which will rust and dissolve the spring, disabling the mechanical regulation of the valve.
The code in my state disallows any mechanical traps or vents.
glennjanie is offline  
Reply With Quote
Old 04-17-2008, 10:46 PM  
triple D
Senior Member
Join Date: Jan 2008
Posts: 296
Liked 1 Times on 1 Posts

Default Just wondering....

Can you send us a picture of current plumbing location, and future location? Might help in offering more precise advice, we're always here to help, or at least make ya lol. Good luck....
[COLOR="DarkGreen"][FONT="Franklin Gothic Medium"]See my work-Check out my album. "Git 'Er Done":D [/FONT][/COLOR]

Last edited by triple D; 04-30-2008 at 11:47 AM.
triple D is offline  
Reply With Quote
Old 05-03-2008, 01:28 PM  
Licensed Master Plumber
Join Date: May 2008
Posts: 6

Actually, a Studor brand Air Admittance Valve uses no springs. It has an ingeniously designed seal that opens under negative pressure in the pipe to allow air into the system and closes under positive pressure. If your local code allows it you can feel comfortable using one, I have installed literally thousands with very few failures. If they do fail you will smell a sewer gas odor and can just replace the AAV (Air Admittance Valve). One thing to be careful of is to use Teflon tape on the threads instead of pipe dope. If you get any pipe dope inside it could interfere with the seal. The same goes for PVC glue.

I am a little concerned that you are going to run your supply lines in an outside wall. Insulation provides no heat and may not protect your pipes if it gets really cold. A better solution might be to bring the supplies up from the bottom of the cabinet if this is possible.

You can do it!

[url=]How To Unclog A Toilet[/url]
mstplumber is offline  
Reply With Quote

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

Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
vent question - moving washing machine mmsphoto Plumbing Forum 2 10-22-2008 09:41 PM
Moving a Kitchen sink - vent lines and drain pipe paulfavre Plumbing Forum 4 10-13-2008 01:05 PM
Tips for Kitchen Improvement kbchome General Home Improvement Discussion 1 08-11-2008 02:28 PM
is it possible to add vent to drain/waste system racerboy6996 Plumbing Forum 2 06-21-2007 05:46 PM
How do I attach a kitchen sink to abs pipe? WalterSobcheck Plumbing Forum 1 06-10-2006 07:16 PM

Newest Threads