Bath Vent

[mjb]

I need to upgrade the vents in a bathroom. The current venting has only the sink being directly vented to the roof. The toilet and tub are not directly vented. Therefore, when the toilet is flushed there is gurgling sounds in the tub. What would be the best way to vent the toilet and tub?

http://www.cornerhardware.com/articles/art51.html

This site shows a similar DWV set up I am considering. The only difference is that they show the vent going to the roof originating from the toilet. My setup has the vent to the roof originating from the sink.

Existing setup sequence--- SINK(vent to roof) > TOILET(no vent)> TUB(no vent)

Cornerhardware setup sequence--- TOILET(vent to roof) > SINK(tied in with toilet vent) > TUB(no vent)

Proposed setup sequence--- SINK(vent to roof) > TOILET(tied in with sink vent) > TUB(no vent)

Can I tie in the new toilet vent into the existing sink vent which is 2" in diameter?

[Phelps]

Who put in an unvented toilet? I never heard of such a thing. Generally the waste line is connected to the vent stack. Both are usually 4 inch. Sometimes 3 inch. The toilet is teed in between the vertical waste and vent. The size of the toilet vent enables you to tap into that main vent with other 1 1/2 or 2 inch vents nearby. Wall sinks by the toilet are often dry vented horizontally above the sink top level and tie into the waste-vent stack. And often the tub is wet vented over to a hub, below floor level in the same 4 inch elbow that the toilet is mounted to. This meets code in my area if this wet venting is within 6 feet of the vent pipe.

For what you propose, I don't think this is kosher. I think your venting size off the sink is too small. You really need to tap into the toilet's waste line and continue that line upward as the vent, I do believe. And then tie other vents into that larger vent.