I had been getting a foul smell in my upstairs bathroom. After consulting several plumbers, one finally broke the floor and found that there was no trap. A trap has now been installed ( I live in a townhouse, the trap is sort of on the ceiling of the dining room area). The trap flows into a 4 inch waste pipe. The toilet waste joins this pipe about eight feet away. There is a two inch vent line on the 4 inch waste pipe. This vent line is about six feet from the bathroom trap, about 2 feet from where the toilet joins the system.
The 4 inch waste runs horizontally about 20 feet to the outside wall of the townhouse.

Is there sufficient venting on the bathroom trap? Or will the foul smell return?

Many thanks.

After consulting several plumbers, one finally broke the floor and found that there was no trap.
What trap was left off? The tub/shower trap?

Is there sufficient venting on the bathroom trap?
Not in my book. If this is a tub/shower trap it should have been connected into the lavatory drain line where it would have been wet vented. As it is the trap's unvented before it reaches the toilet branch. A vent should have been installed before the trap entered the waste line. Regards, Tom

What trap was left off? The tub/shower trap?

Not in my book. If this is a tub/shower trap it should have been connected into the lavatory drain line where it would have been wet vented. As it is the trap's unvented before it reaches the toilet branch. A vent should have been installed before the trap entered the waste line. Regards, Tom


Tom,
Thanks so much. You got it exactly... it was the shower. Should I insist on a vent on the U ? It seems to be working...
Kind Regards,
Angela

Sure it drains OK. However if it isn't vented it's against code. Does the toilet discharge up or downstream from the shower drain? If there's a lavatory directly upstream from the shower drain then the shower could be wet vented by the lavatory vent. Let me know, Tom?

Does the toilet discharge up or downstream from the shower drain?

Tom,

I think the toilet discharges downstream of the shower drain.

When I stand in the dining room and look up, the system is horizontal across the roof. The beginning of the system is the U trap in the drain of the shower. This empties into the 4 inch waste line. Next is a 2 inch vent off the top. Then the toilet enters. I cannot see where the lavatories enter the 4 inch pipe. Most of the system is sealed in a gypsum tunnel. The end of it - where the U trap has been installed- is the only piece exposed. I bet that the one 2 inch vent is the only vent for the whole system - two lavatories, one toilet and the shower ( going left to right).
Regards,
Angela

It liooks like the shower may be wet vented by the 2 inch vent on the 4" branch. I sure hope the lavatory's vented but I have grave doubts about a system that has a shower installed without a trap. ( scratches head) I don't know of any plumber that, drunk or sober, would install a fixture without trapping it first. We just don't do that! Regards, Tom

It liooks like the shower may be wet vented by the 2 inch vent on the 4" branch. I sure hope the lavatory's vented but I have grave doubts about a system that has a shower installed without a trap. ( scratches head) I don't know of any plumber that, drunk or sober, would install a fixture without trapping it first. We just don't do that! Regards, Tom


Dear Tom,

I live in the Caribbean; and I love it. However, codes are intermittently enforced! So please believe, they installed 2 showers without traps in both bathrooms in the townhouse. And it's a new development. The only reason it took a little time to decide to break the floor in the second shower is that there was a water level in the drain pipe! But after 2 months of foul vapors, I convinced them to break the floor - guess what? There was an elbow in the line, that's all! An elbow connected the drain from the shower to the 4 inch waste.
You cannot imagine how many plumbing experiences I've been through in the past 2 months. They don't use very much thread seal tape either! :)
Thanks to you though, there is one more single mother who has learnt some plumbing. They need a new trick to pull the wool over my eyes again.
My daughters and I are very grateful to you for all your help. ( And we have fingers and toes crossed that the lavatories are vented.)
Sincerely,
Angela

I live in the Caribbean; and I love it.
Ahh! The Caribbean. After WW2 I was discharged from the Navy, joined the Merchant Marine and sailed sugar boats to Cuba and tankers all over the Caribbean. One of the reasons we relocated to Florida from Wisconsin was the time I spent around the islands in the winter time. No more frozen toes for this dude! I wish you well Angela and if I can ever be of assistance I'm as close as a click. Cheers, Tom