House in Maryland is two years old with basement bath rough-in installed during construction. Plumber came in to install water piping and drains for sink and laundry tub which looks fine besides the fact nothing is vented. He is telling me that all the drains are connected to the venting system already installed in the house. Is this correct? Also the rough in for the toilet hasn't been touched nor has he installed a water line for the toilet. Plumber is scheduled to return after the drywall but I have a gut feeling that I am gettting some bad information and may have problelms later. Any assistance would be greatly appreciated.

Sorry to disagree with your gut feeling, but fortunately for you, your plumber is correct.

First of all, if the rough-in was done during the original construction, there is no way it would have passed the inspection if it was not vented. Second of all, almost all bathroom groups are vented the same way: all the fixtures get "wet-vented" through the sink's drain pipe. Meaning, whereas the other rough-ins are coming out of the floor, the sink is coming out of the wall, so obviously there is a vertical pipe inside that wall going from the floor up to the sink stub-out, right? Well, that vertical pipe doesn't end at the sink stub-out; it continues up the wall through the ceiling, and that vents the sink. The other fixtures are then tied into the sink's drain line, so they can all share the sinks vent.

So don't worry, everything's okay. Enjoy your remodel!

Cheers,
Moishe
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Fiest, thanks for the prompt reply and I am pleased that you disagreed with my gut felling. There is a stub-out near the wall for the sink drain. He installed the vent but "capped it off becasue of the difficulty of reaching an vent to the outside or as he said, tapping into another vent". This is when I started gettting that 'gut' feeling. If this is fine I will leave it as is. What about the water supply line to the toilet? Should it be installed before I put up the drywall? Is a good practice to install the toilet flange before the flooring is installed?

Moshie was "bang on" in his answer. You should be vented by the lavatory vent. However, if he capped off the vent coming off the lavatory tee then your group isn't vented al all. The cap will have to be removed and a vent run, (1) out the roof, (2) up and revent back into a exsiting dry vent at least 6" over the flood rim of the highest fixture that vent services, (3) Take the vent up to the attic and revent back into a roof vent, and last, (4) ask your plumber if local codes will allow you to install a AAV, ( Air Admittance Valve) "Cheater Vent" (see image). If you can use this type of vent then a vent out the roof won't be necessary.

What about the water supply line to the toilet? Should it be installed before I put up the drywall? Yes, The water supply line should be installed behind the dry wall.

Is a good practice to install the toilet flange before the flooring is installed?
First install the flooring and then set the flange on top of it.

Good luck, Tom

Moishe and Tom you have been a great help. Plumber coming by tomorrow and since he capped off the vent not sure if he is being honest. Looking at the setup of my basement and the bath location the only place I can see the vent going is out the side of the house. Can the vent be run through the side of the house instead of the roof? If so, will this cause any problems? Not sure of code but looking into it. Just want some info in the event he suggest venting it to the side of the house. Thanks in advance.

Adrian

Hi Adrian,

Section 1404.5 of the Standard Plumbing Code Titled " Vent Extensions Through Wall" will allow this with the inspectors approval and if it meets the requirements of Sections 1404.4 and .5. If this is what you plan and wish to know the restrictions click on back and I'll print out both Sections. Regards, Tom