I'd try to replace it with another glued-in T. Oddly I've found that after cutting out the fitting there is often enough movement in the pipe to either get a coupler plus the T or just pull the cut ends into the new T without having to resort to a fernco.

Since the leak is in a vent, not a drain, you may be able to seal the leak by simply running a bead of PVC solvent (adhesive) around the leak.

"Since the leak is in a vent, not a drain, you may be able to seal the leak by simply running a bead of PVC solvent (adhesive) around the leak."

That's a good solution. Wrap some duct tape around it too, and a couple hose clamps. If that doesn't work drive a few nails.

Thanks guys, (for the sarcasm, too)

Though it's always a little tempting to seal it and see what happens, I will replace it for peace of mind...(but it is tempting to try!) Still, six months down the road I don't want to explain to someone why the ceiling needs to be patched again.

"I have a leaking sanitary tee fitting in a horizontal vent in an attic."

If it is a vent there will be no liguid leaking. If there is liguid leaking it is not a vent.

That's what got me on the original post, if it is a vent and carries only air how do you know that it is leaking?

Except when it's rainwater. This one leaks on rainy days.

In fact, this is the 4th leaky vent pipe I've discovered over the last couple years. On two of those occasions there was a single joint that didn't get glued.

Quote-"if it is a vent and carries only air how do you know that it is leaking?"

In theory it is true that vent lines are intended solely to allow the movement of air however in actuality there is a lot more liquid than one might imagine in a vent line. In addition to rain water which might enter the pipe as was mentioned above, it must also be understood that while discharging steam or hot water vapors a substantial portion of the steam or vapor will condensate on the interior of the pipe and flow back down in the form of liquid.

My question is why is there a sanitary tee on a horizontal line?

If this is a horizontal line connecting to a vertical stack code would require a sanitary tee on the stack however Code prohibits installing sanitary tee's horizontally. When it is necessary to connect a riser to a horizontal line the code requires that we use a Wye & 1/8 bend.

As was mentioned earlier, their may be enough free movement in the pipe to permit installing a common glued in fitting but such is not the case in all instances.

The solution is to use "repair couplings" in place of common couplings. Common couplings have a raised ridge at the centerline of the fitting to insure that each pipe is inserted halfway into the coupling. "Repair couplings" have the same general appearance as a common coupling, however they do not have the internal raised ridge therefore a repair coupling can be slide entirely on a pipe.

When making a repair we begin by installing a short nipple of pipe on all three openings of a sanitary tee or Wye & 1/8 bend. We then cut the existing line at the point where it will make a good butt connection with the ends of the nipples. Nest we slide a repair coupling completely on the pipe so that the cut ends of the pipe are exposed 2" or 3". Te repair assembly is then slide into the opening of the pipe were the nipples will make a tight butt connection with the existing pipe. Solvent and glue is then applied to both the pipe ends and the nipple ends and the repair couplings are quickly slide over the connection and rotated a bit to insure an even spread of the glue. In this manner you can make a tight fit in places where you can not get any movement in the pipe.

Thanks for the info.

It's definitely a sanitary tee (1 1/2, 1 1/2, 1 1/2) used to merge two horizontal vents (perpendicular) and then continue down the line (horizontally) and then turn 90 degree horizontally and after traveling 6 more feet it turns up, merges with another 2" vent, and up and out through the roof. The straight horizontal portion is as least 20 or more feet long.

As an aside (I did inform the customer, but they didn't want to deal with it at the moment), a 4" vertical vent terminates inside the attic in the same area. And this is a 600k upscale house that was build about 4-5 yrs ago - go figure. Like I said, I told them, they just closed on the house, but they just wanted to talk about it with the home inspector, etc. - life goes on.

alphonse said: "That's a good solution. Wrap some duct tape around it too, and a couple hose clamps. If that doesn't work drive a few nails."

Yuk Yuk.

I can see alphonse has never worked with PVC pipe or worked as a plumber for that matter...

smiles.

Sanitary tees are acceptable in the horizontal position on dry vents ONLY. This is pretty clearly not a wet vent since it's in an attic, so you're fine. The installation as you described it sounds fine, assuming that it has a slight slope AWAY from the roof penetration. That's so condensation/rain will drain back into the drain part of the system. The way it's tied in sounds just fine for a dry vent.

The usual reason for using a sanitary tee instead of a vent tee in this application - which would also be acceptable - is that it's one less part to bother stocking. Same reason 1.25" lavatory sinks use 1.5" traps.

Now, the 4" soil stack terminating IN the attic does sound like a problem. It's just open to air within the attic space? What code is this under and can you post pictures?