Does a bathtub/shower vent through a vent that goes all the way out of the house (eg. Straight up out of the roof), or does it use the overflow for venting? Or does the entire drain stack just have 1 vent for the tub/toilet and sink?

I ask because I have a very slow tub drain, and no matter how much I snake the drain, or use the liduid stuff, it doesn't seem to help. I am wondering at this point if the vent is not adequate. I did not install this tub myself, the builder did, and I have had problems ever since my home warranty expired (imagine that!)

Thanks

BM

If your tub isn't vented or there's a problem with it then you will hear a gurgle sound from the trap as it vents through there. Bathtubs and showers are vented in one of two ways. 1) by running a individual vent just after the trap to revent back into the lavatory vent and then through thr roof. **or** 2) By wetventingand only using one vent for the entire bathroom group. Let me show you.
Most bathroom groups are roughed in like this.
Toilet connects to sewer main or the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes.to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic or if you're reventing back into a fixtures dry vent you must make your connection at least 6 inches over that fixtures flood rim. Does this answer your question? Regards Tom

That answers my question well. There is no gurgle sound, so it must be a clog further down than I have been snaking it. I think I need a better snake that I can hook to my drill. The manual one is a pain in the you know what.

Thanks again.

BM