Hi there,

As we were planning our basement remodel, the plumber we called in to bid on the job mentioned that none of our existing plumbing was vented. This would pose a problem for us when we would want to get the remodel inspected.

For most of the sink drains I was planning on using Studor vents (Air Admittance Valves), but what can I do about the main floor bath tub and toilet?

Can I studor the bath tub?

Can I studor the toilet? I don't think I can go through the walls and out the roof, so what else can I do?

Would appreciate any advice!

Thanks,
Doon

Hi Doon...

All really depends on the inspector and prevailing codes in your area. I assume you have confirmed that studor vents are allowed in your area... correct? Are MULTIPLE studor vents allowed? Most places will allow one or even two, but pretty rare for an entire home to use only studor vents.

If they are allowed you need to know that they need to be installed so they are at least 6" above the PTRAP and they need to be accessible for replacement should the studor vent fail in the future. You can keep the studor vents accessible by keeping them in a vanity cabinet or if you have a pedastal sink you can run them into the wall if needed as long as you have an access panel.

All that being said, you are on the right track when saying that you planned on using the vents at each sink. That is the right place to start.

Next, you would need to check to be sure that WET VENTING is allowed in your area.

If wet venting is allowed, then you may be able to wet vent the toilet and the bathtub using the bathroom sink vent. Here, the 2" lavatory drain and 2" studor vent will act as a wetted vent (sink drain meakes the vent wet) for the toilet and the tub. The tub waste and the sink waste will need to connect directly into your toilet drain. Check out the following diagram below. This drawing is only a rough idea for you, but you should get the idea anyway.

It may also be a good idea at this time to add a 3" vent through the roof using the basement bathroom remodel... up to you and the inspector, of course.

Finally, don't hesitate to contact your local plumbing inspetor and discuss this with him. I am sure he must run into it all the time in your area...you could even be "grandfathered in" in terms of the old work, but the new work will undoubtably need to be brought up to code... ;).

See what you think here... let us know.

MARK

Mark gave you a excellent answer complete with a image. Wet vents are allowed in my area so let me tell you how you can get away with just one vent for the entire bathroom group.
Toilet connects to sewer main. 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.. ( this is where you would install a AAV) 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.. Good luck and thank you for rating my answer. Tom