Return to the Bathrooms Forum | Post a Follow-Up

 o
Moving a vent stack

Posted by mabeldingeldine (My Page) on
Thu, Mar 11, 10 at 6:44

What does moving a vent stack entail, especially regarding the roof? In my earlier post about a small bath floor plan, responders suggested moving the vent stack.

The bath is on the first floor. On the second floor, the stack is hidden in the drywall. The roof is fairly new asphalt shingle with a large layer of Grace Roof and Water Shield in the area where the vent stack now emerges.

Should a vent stack be enclosed in an exterior wall? Especially in a cold climate (Maine)?

I'm afraid the cost of this will blow our budget but perhaps I am incorrect. Thanks for your help.

Here is a link that might be useful: Bath before photos


Follow-Up Postings:

 o
RE: Moving a vent stack

It'll be a lot easier and cheaper if it's PVC. I can't tell from your photo.

Also- is this the primary vent or a secondary? I don't know about the primary, but I know the secondary doesn't have to be a straight vertical run. So, you could leave the part that goes through the second floor and out the roof, and just tie into it between the floor joists. Move the first floor section and then make a jog over to the rest of it. That's what we did. There are rules for horizontal distances from each trap to the vent that you will need to take into consideration, too.
I live in Maine, too, and our plumber said it was no problem having our vent pipe in the exterior wall (it's not the main stack but seems like it should be the same?) since it's not a pipe that is filled with water that can freeze.
Cost-wise, I can tell you that it cost us $850 to have an entire bathroom DWV syestem re-plumbed, including reconfiguring the main sewer outlet, adding new rough drain pipes for toilet, tub, shower, and lav, adding a new secondary branch vent and moving another one (both tied into the main roof vent.) This was all PVC, though.
Hope this helps!


 o
Cost of moving your vent stack.

Your vent line shown looks like white PVC pipe to me. With every city and country having there own set of code it's hard to tell you exactly what you can or can't do. I can tell you that here in Vancouver if I where preparing a estimate for you to budget by - it would would look like this;

Plumber;
Remove existing vent - 1hour
Repipe new vent location - 4 hours
Flood Test - 2 hours

Materials, fitting, glue etc $150.00

Total plumbing estimate $850.00 - $1100.00

Repair upper floor and new drywall $500.00 (if done at same time as bathroom work)

New roof vent and roof repair - $450.00 (this may not be need since it might be possible once above your upstairs flood level rim to angle back to the existing location

Most homes are required to have on 3" vent line - the rest can be sized as needed. This may be your main and you could have other vents or drain lines tied into it. It might be possible to increase the size of a second vent and decrease the size of this one shown.

As a rule of thumb I estimate $2,000.00 for a stack move - more if its cast iron, and more again if it needs to be built in cast iron.

Your plumber can help you determine the best route to take, and insure you look up your codes on drilling and notching framing members.

Have you considered a short privacy wall to block in the stack? Some times a rooms layout can be changed to allow for this - and then you will be able to take the $1,200 savings and spend it on a new vanity and fixtures!

I might suggest you replace your white PVC drain pipe with Black Cast Iron pipe and leave it exposed and go for an old school look. Many fine home have exposed plumbing - it just usually is Cast Iron painted white not white PVC piping.

Good Luck,

John Whipple

"When it's perfect. It's good enough."


 o
RE: Moving a vent stack

Thanks to both of you, it does indeed help. This is naturally the main stack, and it is indeed PVC.

Stacey what does DWV system mean? I haven't learned all the bathroom argon yet but I'm sure I will. BTW I love your bath redesign and hope it all turns out well!

John, one option we are discussing is hiding the stack in a wall, but can't figure out the spacing. Any advice you can lend is more than welcome.

We are lucky in that in my small rural town there are no codes relating to fixture distances in the bath, we just need to worry about useability.

Here is a link that might be useful: my original layout post


 o
RE: Moving a vent stack

DWV= drain waste vent; basically the rough plumbing from the sewer to just before the fixture's trap, including vents.

So, in your town you don't have to pull a plumbing permit and have the inspector come over? I was under the impression that everyone in Maine had to follow the national plumbing code... (and then some towns have additional stricter codes.) I may be wrong. But, anyway the codes for horizontal distances and pipe sizes are for usability: you don't want your toilet backing up into the sink because its not vented properly. Eeeeewwww.


 o
RE: Moving a vent stack

Thanks, Stacey. We will need a permit, what I was referring to is the fixtures, sink, toilet, etc., have no limits on placement. The plumber at my workplace said basically you couls situates them such you could be wash up from a seated position if you wanted. He said Maine has not yet adopted the universal plumbing code, yet. Our rural codes are much more lax than most city codes, but you are correct, no backing up!


 o
RE: Moving a vent stack

By my understanding of the plumbing code is that a vent can't travel horizontal until it is above the flood level of the tallest fixture (sink). This means it has to travel at 45 degrees towards the exterior wall.

Again the work saved and work needed to be done is not much more weather the stack moves 2' or 6'.

Find a seasoned builder or plumber. Renovating homes is always a balance of creativity and problem solving. There are a million types of plumbing fittings and combinations and no two plumbers would plumb this job exactly the same.

Never loose sight of your homes structure and insure your plumber does no harm in the relocation. Have your city inspector check the work and flood test the new pipe before you cover it all up.

Good Luck.


 o
RE: Moving a vent stack

If that stack is simply the vent...meaning that no waste from the floor above flows down through the pipe...then it could be a fairly simple relocation.

It could be as simple as relocating the connection in the basement, relocating the pipe into the wall, and remaking the connection in the floor above. Dry vent pipes don't necessarily have to be pitched, they can run horizontally for a bit.

If the pipe is a wet waste pipe as well, then there are other issues that need to be honored and it could be more costly.

Regardless of what the pipe does within the envelope of the house; ie, if it's a simple vent or a wet waste pipe -- once you get the relocated pipe into the attic space you can use a coupling to reconnect the relocated pipe to the existing pipe stub that goes through the roof. By then it's just a vent pipe, so you can jog it horizontally or at a 45 as needed to make the connections. You shouldn't need to cut a new hole in the roof to relocate the boot.


 o
RE: Moving a vent stack

If you can make a sloped angle in the space between the rafters and just move it back into the exterior wall, I'd say it'd add no more than $500 to the cost if the main waste stack can easily be altered below. I thought this was on the 2nd floor--in that case, it's be less than $300 if you're already ripping everything down to studs. Here, I'd leave the upper floor alone, if possible, and just change the lower part.


 o
btw...

If you can afford to, get it stripped down to studs before you call in the plumber, and you'll get a LOT lower estimate!


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Bathrooms Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here