Nail in my vent pipe

brockmiera · 11-30-2012, 12:15 PM

Ok so I am demoing my basement bathroom and puling out the drywall nails from the studs and I see that the previous owner had driven a drywall nail right into the vent pipe. The vent pipe is cast iron (I think). Above it will be the sink in the basement bathroom and the sink from the new bar as well as the sink from the upstairs bathroom.

My question is this - Do I need to replace the entire vent pipe? Do I leave in the nail? Is there some type of patch I can use if I pull out the nail?

brockmiera · 11-30-2012, 05:37 PM

Another question. How big of a job would it be to just replace that vent/drain pipe with pvc? Where would I start?

**TheEplumber** · 11-30-2012, 07:48 PM

You got an ugly one there! I think you're dealing with a copper drain, not cast iron. The nail needs to come out and a repair made. Can you see a cast iron hub at floor level or slightly below? That pipe ties into the 4" below slab so there has to be a transition from cast to copper. That's where you make the repair. Once you find that spot, clean out the cast iron hub and use plastic from there. Pull out all the copper drain you can since you have the wall open. (recycle it for good cash)
You mentioned a future second floor sink- it should tie in below the tee that serves the basement lav- above the tee is the vent and you shouldn't wet vent 2 floors, let alone on that small of pipe. Hope that helps.

brockmiera · 12-03-2012, 05:13 PM

Quote:

Originally Posted by TheEplumber

You got an ugly one there! I think you're dealing with a copper drain, not cast iron. The nail needs to come out and a repair made. Can you see a cast iron hub at floor level or slightly below? That pipe ties into the 4" below slab so there has to be a transition from cast to copper. That's where you make the repair. Once you find that spot, clean out the cast iron hub and use plastic from there. Pull out all the copper drain you can since you have the wall open. (recycle it for good cash)
You mentioned a future second floor sink- it should tie in below the tee that serves the basement lav- above the tee is the vent and you shouldn't wet vent 2 floors, let alone on that small of pipe. Hope that helps.

So I'm assuming that means busting up the slab that is there to find this junction point? Once I find it and pull it all out of there, is there a pvc to cast iron coupling or sleeve that I need to use?

VIPlumber · 12-05-2012, 12:18 AM

Quote:

Originally Posted by brockmiera

So I'm assuming that means busting up the slab that is there to find this junction point? Once I find it and pull it all out of there, is there a pvc to cast iron coupling or sleeve that I need to use?

Yes, you'll need to cut up the concrete to find the transition point that E-Plumb is talking about. As for the coupling to transition from cast iron to PVC, you'll to need to use a shielded coupling, as in the pic, for anything buried in or below concrete.

brockmiera · 12-05-2012, 11:08 AM

Quote:

Originally Posted by VIPlumber

Yes, you'll need to cut up the concrete to find the transition point that E-Plumb is talking about. As for the coupling to transition from cast iron to PVC, you'll to need to use a shielded coupling, as in the pic, for anything buried in or below concrete.

Does anyone have a picture of what the connection from that copper pipe to the main sewer drain look like?

Also, EPlumber mentioned that the drain might be sized too small for the 3 sinks that will use it. If I'm going to replace the whole thing what size should I put in? 3"?

Alan · 12-05-2012, 11:59 AM

I hate working with copper drains. The OD is all screwed up.

I once pulled out a copper vent that was tied into a 3" stack which I assumed was the vent for the mainline. It was tied in with an upside down wye which is one way to do it (not wrong) except that the 3" was actually a toilet drain, not a vent. You can imagine what I found in that vent.

Anyway :

The other option for changing the transition is to use a "Fernco Do-nut" You pull all the lead and pipe out of the cast iron hub, slide the donut over your pvc or abs, and hammer the donut into the fitting. Makes a nice tight rubber seal and a clean transition without having to cut any cast iron out.

brockmiera · 12-06-2012, 02:49 PM

I guess I'll know better what my next step should be once I open up the floor and see what I've got.

COLDIRON · 12-07-2012, 08:03 AM

If you know how to solder the easiest way to fix it is to pull the screw out and solder a small copper patch over the hole. It should last forever. No digging, no fittings, no PVC.

brockmiera · 12-07-2012, 09:05 AM

Quote:

Originally Posted by COLDIRON

If you know how to solder the easiest way to fix it is to pull the screw out and solder a small copper patch over the hole. It should last forever. No digging, no fittings, no PVC.

So just clean it up and sweat a patch on? that seems pretty easy.

tylernt · 12-07-2012, 10:16 AM

Quote:

Originally Posted by brockmiera

So just clean it up and sweat a patch on? that seems pretty easy.

I have no experience with copper DWV, but patching with solder makes far more sense to me than busting up a slab.

Alan · 12-07-2012, 10:24 AM

I guess you COULD do that. To make it work properly, you'd need something the right size, which would be a piece of a fitting.

Keep in mind that getting to the pipe underneath may not be necessary, but copper doesn't last as long below grade. It wouldn't hurt to pull it out if you only have to remove a short section of pipe to replace it.

Besides, then you can upsize it which will make it less likely to clog, and give you the flexibility to add another fixture to that part of the line later if need be.

brockmiera · 12-07-2012, 10:47 AM

Quote:

Originally Posted by Alan

I guess you COULD do that. To make it work properly, you'd need something the right size, which would be a piece of a fitting.

Keep in mind that getting to the pipe underneath may not be necessary, but copper doesn't last as long below grade. It wouldn't hurt to pull it out if you only have to remove a short section of pipe to replace it.

Besides, then you can upsize it which will make it less likely to clog, and give you the flexibility to add another fixture to that part of the line later if need be.

The patch would be above slab albeit below grade since its in the basement.

Since my plan is to add a small bar sink to that drain/vent line, I would have to cut out a section anyway. Does it make sense to cut the pipe by the floor, take out a 3-4' section and replace it with PVC? I dont even know if that is allowed by code. I can do the work but knowing what work is correct and what will last is where I am lacking. If this is doable what types of transition fittings would I need?

Alan · 12-07-2012, 08:19 PM

The answer in my code would be : "You need a 2" drain for a bar sink"

The second problem you run into would be depending on where and how you cut in your fittings, you COULD possibly be "wet venting" one of the fixtures, which also requires the wet vented section to be upsized one pipe size larger than the minimum required drain. That's if wet venting is allowed in your area, and what the specific rules are for it.

brockmiera · 12-07-2012, 08:32 PM

Quote:

Originally Posted by Alan

The answer in my code would be : "You need a 2" drain for a bar sink"

The second problem you run into would be depending on where and how you cut in your fittings, you COULD possibly be "wet venting" one of the fixtures, which also requires the wet vented section to be upsized one pipe size larger than the minimum required drain. That's if wet venting is allowed in your area, and what the specific rules are for it.

Whew! Thats a lot of info. Im no plumber but it looks like i have a lot more research to do.