Hello,

I will be totally gutting and redoing my home's only bathroom next month and am trying to iron out any problems now before I start ripping things apart. I have a few questions about the best way to do things...

The main waste/vent stack is cast iron, and runs vertically through the corner of the room near the toilet. Here is a picture where I cut the floor and wall open to check things out: http://img404.imageshack.us/img404/3863/stackrw5.jpg

That big horizontal part goes over about a foot to the toilet. Reaching my hand in, I can feel some threaded pipe coming off that with a PVC connection. I cut the wall open behind my vanity, and saw PVC running from the drain, down the wall, and across the floor towards the toilet. The same goes for the shower. Here is a crappy not-to-scale floor plan: http://img119.imageshack.us/img119/6...oorplantw8.jpg

My first question is about venting. Currently, nothing is vented at any of the fixtures. The drains for the shower and vanity both run straight to the toilet drain with no vent anywhere along their lengths. Is this OK?? Are they close enough to the main stack to be vented by that? The bathroom is small (6'x7') and both fixtures are within 6' of the stack.

Secondly, I will be moving the toilet across the room during the remodel. This requires extending the current drain about 5' along the joist cavity (no need to cross any joists). I was disappointed to see all that cast iron! Is there any way to extend from the existing cast iron drain without cutting into the stack and replacing with PVC? If not, I guess I would cut about a foot above and a foot below the floor and replace with PVC using those neoprene banded couplings? I'm afraid to use a snap cutter on the old, brittle cast iron... Any recommendations on sawzall blades or other cutting methods? Searching these forums I heard angle grinders work well, but I don't think I could get all the way through the pipe with one... Also, are cast iron riser clamps (mounted to the framing) sufficient to hold the stack while I cut and remove a section?

The current supply lines coming up from the basement are 1/2" copper to feed the whole bathroom. When all is said and done I will have a single sink vanity, toilet, and standard 5' whirlpool tub/shower. Would it be prudent to run 3/4" up instead or will 1/2" be enough?

Hope I have given enough info... Thanks so much guys! :D

I will be totally gutting and redoing my home's only bathroom next month and am trying to iron out any problems now before I start ripping things apart. I have a few questions about the best way to do things...

Good luck and take lots of pictures…..

The main waste/vent stack is cast iron, and runs vertically through the corner of the room near the toilet. Here is a picture where I cut the floor and wall open to check things out: http://img404.imageshack.us/img404/3863/stackrw5.jpg

Ouch…that does look old!

That big horizontal part goes over about a foot to the toilet. Reaching my hand in, I can feel some threaded pipe coming off that with a PVC connection. I cut the wall open behind my vanity, and saw PVC running from the drain, down the wall, and across the floor towards the toilet. The same goes for the shower. Here is a crappy not-to-scale floor plan: http://img119.imageshack.us/img119/6...oorplantw8.jpg

Doesn't look that bad…I like the layout

My first question is about venting. Currently, nothing is vented at any of the fixtures. The drains for the shower and vanity both run straight to the toilet drain with no vent anywhere along their lengths. Is this OK?? Are they close enough to the main stack to be vented by that? The bathroom is small (6'x7') and both fixtures are within 6' of the stack.

By rule of thumb as well as international plumbing code anything with a trap should be vented no matter what…

Secondly, I will be moving the toilet across the room during the remodel. This requires extending the current drain about 5' along the joist cavity (no need to cross any joists). I was disappointed to see all that cast iron! Is there any way to extend from the existing cast iron drain without cutting into the stack and replacing with PVC? If not, I guess I would cut about a foot above and a foot below the floor and replace with PVC using those neoprene banded couplings? I'm afraid to use a snap cutter on the old, brittle cast iron... Any recommendations on sawzall blades or other cutting methods? Searching these forums I heard angle grinders work well, but I don't think I could get all the way through the pipe with one... Also, are cast iron riser clamps (mounted to the framing) sufficient to hold the stack while I cut and remove a section?

You may want to use a saddle tee instead if you have room I'm sure that cast is very brittle and it will just keep crushing if you try to us snap cutters. Here is a link for you to see what I'm talking about

PVC Saddle Tees plumbing products

The current supply lines coming up from the basement are 1/2" copper to feed the whole bathroom. When all is said and done I will have a single sink vanity, toilet, and standard 5' whirlpool tub/shower. Would it be prudent to run 3/4" up instead or will 1/2" be enough?

Hope I have given enough info... Thanks so much guys!

What size line is feeding your house? ½ will carry a lot more than people think but it depends on the type of pressure you have or want as to the size that you may want to use…hope this helps. PVC Saddle Tees plumbing products

plumberman was bang on when he said that every fixture that has a trap must be vented. However, ther's a way around having to run a vent for each fixture.
If you retain the set up in the drawing you can run a vent off the lavatory through the roof or revent back into a dry vent you will have wet vented the shower and toilet and will only have to run one vent for the group. Could you post a drawing showing the new location of the toilet in relationship to the lavatory drain and how the drains will connect?
Why cut into the stack at all? Why not cut out the closet bend and convert to PVC from there? Am I missing something here?
Our code calls for no more then three fixtures on 1/2" branch. as Plumber man pointed out a 1/2" pipe will carry a lot of volume. You should be Ok with 1/2". Good luck, Tom

Thanks plumberman.

Was it ever common practice to not have any individual venting or did some one before me just mess things up?

One other quick question - when I turn on my sink after it has been sitting unused for a few hours I get a little burp of sewer gas for the first few seconds. Do you think the lack of proper venting would explain this?

Assuming I run a new 2" vent for the lavatory, can I wet vent the shower/tub through this? Are there any special distance requirements for this?

Thanks!

EDIT - whoops, I posted this before I noticed speedball's reply... I will post a diagram of the proposed layout ASAP. Thanks guys!

OK, as for cutting into the closet bend and not the stack... I don't know what to say other than that's a much better idea! I don't know what's wrong with me for not thinking of such a simple thing... Thank you! I think all the tutorials that I've seen for re-plumbing or adding a bath all involve cutting out a portion of stack and replacing it with PVC, so I just always kind of assumed I would be doing that... Whoops.

Here's a picture of my proposed layout: http://img113.imageshack.us/img113/5179/newbathpm8.jpg

If this is OK, I am not sure of the best fittings to use to tie everything together there near the PVC transition... I know to sweep as much as possible and avoid 90° elbows... Any suggestions or things to avoid would be appreciated.