skip to main content

Home Disasters The Old House Plumbing

Sewer smell coming from the shower stall

3 years ago

Here's some quick background information:
The ADU was built on slab foundation some 40 years ago and tenants were living there for a long time. I purchased the house 1.5 years ago.
During Covid, the one bedroom unit was unused for roughly 6 months as the tenant was working from a remote location. A new tenant moved in to the unit in November and a new hot water tank was installed end of January. The unit only has one vent going thru the roof (from the bathroom) and I am certain the ADU sewage line is connected to the main house in the front.

Problem:
By mid February, the tenant told me that he was noticing a sewage smell from the shower stall about 10 minutes after having a shower. He also sometimes smell it when he uses the bathroom sink.

What he did so far:
Pour bleach, baking soda, vinegar, etc. The smell went away for a few a week and came back after that.

Plumber/Rooter opinion/suggestion/recommendation so far
Bunch of plumbers / rooters stopped by and gave me different stories
- I don't know what it is. You need to call a rooter.
- You need a new vent but I don't do this job
- Unfortunately I don't know what is causing the problem
- It is a code violation and the problem could be with the P trap and it is not going low so you need to look at or build a septic tank
- You need to gas the place to see where the problem is
- I think the pipe is broke somewhere bu I can't use my endoscopic camera as it won't show anything

Before going on this goose chase, I would like to get your expert opinion. Appreciate your help.

Thanks in advance.
Best.

Sort by:Oldest

Comments (5)

PRO
Ripped Jeans Construction
3 years ago
I'm assuming you are saying you have one roof vent, not that the individual fixtures aren't vented?

The obvious candidate is that there is a blockage in the vent between the roof and the shower that's causing low pressure on the sewer side of the shower trap, and pulling the water out of the trap. Did somebody check that the vent all the way to the shower was clear?
klem1
3 years ago
Your ADU should have at least two MIPs joined by a single TRC. Tighten bolts holding TRC in place.
Related Discussions
sewer smell in new shower
Q
Comments (4)
hi coolvt, our contractor said that all of our drains have ptraps. so far, the shower and all of our other sinks, etc, drain quickly. we had our contractor come back and he cleaned out the shower drain and flushed it out with water as well. we checked all of the cleanouts around our house and they seem ok, so i don't think there is still a clog anywhere anymore. i also scrubbed the floor and everything with bleach and soap and doused it with boiling water, so i don't think the smell is from residual sewage. but in the hot afternoon, the entire bathroom still fills up with an overpowering sewer smell or gas. when it is cooler outside, the smell lessens to some degree. do you think it is from a leak in the ptrap or a venting problem? how do we figure out which it is? thanks so much for your help!
...See More
sewer gas smell coming from drain in basement
Q
Comments (5)
Your trap is dry. The forced air causes the water to dry rapidly because of the pressure imbalance. This is a common problem in commercial building lavatories where the exhaust fan runs constantly. A solution is to add a fresh air intake vent in a basement window to balance the pressure. Another solution is to completely seal off the basement from the climate controlled zone of the house, but it sounds like your basement is part of the conditioned space of the home (most likely through the old floor boards). A third solution is to put water down the floor drain every day. The hole you see in the side of the floor drain is probably a tee that runs to your foundation drain system.
...See More
Sewer Gas Odor in Shower Stall
Q
Comments (2)
It might not be vented properly, or the vent could be plugged, or there could be no shower P-trap, or the floor drain is dry or it has no P-trap. I suggest you contact a plumber to diagnose this if it's beyond your skills. I'm not meaning to be insulting, it's just that this could be something simple or it could involve using sophisticated equipment such as a drain inspection camera that most homeowners don't have.
...See More
Sewer Smell from Bathtub drain
Q
Comments (10)
1. From the base of the VTR (Vent to Roof) to the Wye at the closet bend you have a horizontal dry vent. CODE Prohibits any horizontal dry vent offset until the vent reaches an elevation at least 6" higher than the flood level rim of the highest fixture served by that vent. 2. The Trap on the 2" from tub is constructed with 1/4 bends and a return bend thus the water level in the trap exceeds the maximum allowable depth. (Code requires using Street 1/4bends & Return Bend to make a trap.) 3. It appears as if the line from the kitchen sink is tied in upstream from the trap in the picture. If so and if there is a trap at the kitchen sink location, you then have two traps in series, which is code prohibited. If there is no trap at the kitchen sink you then have two unlike fixtures sharing a common trap, also code prohibited. 4. The tub drain line is connected to the main drain by means of a horizontal Sani-Tee which is prohibited. Code requires a Wye & 1/8 bend. Need I go on????
...See More
Sigrid
3 years ago
I'd start by looking up the code for u-traps under the sink and roof vents. If both are to code, make sure they aren't blocked.

Also look for floor drains. My house has a floor drain in the basement. Over time, the water in the trap evaporates, allowing sewer gas into the basement. Why anyone put a floor drain in the basement is a mystery to me.
SjcHandy SJC
Original Author
3 years ago
@Ripped Jeans Construction No one checked the vent.
shivece
3 years ago
We recently had a similar issue after installing a new septic system. Plummer came a few weeks ago now and suggested that before drastic measures like modified venting, we start by treating all the sinks, toilets, showers and tubs upstairs (area with smell) overnight with BioOne, a blue liquid. So far, so good. We don’t use them all regularly and apparently that can be how the issue starts.

Related Stories

A Little Love for the Shower Stall

BATHROOM DESIGN Shower Curtain or Shower Door?

By Lara Sargent

Find out which option is the ideal partner for your shower-bath combo

SELLING YOUR HOUSE A Moving Diary: Lessons From Selling My Home

By Laura Gaskill

After 79 days of home cleaning, staging and — at last — selling, a mom comes away with a top must-do for her next abode

DECORATING GUIDES 25 Design Trends Coming to Homes Near You in 2016

By Mitchell Parker

From black stainless steel appliances to outdoor fabrics used indoors, these design ideas will be gaining steam in the new year

BATHROOM DESIGN 8 Stunning and Soothing Shower Designs

By The Inman Company

Step into these brave bathroom designs, from Roman inspired to supermodern, and let the ideas wash over you

INSIDE HOUZZ See a Couple’s New Spa-Like Bathroom From Lowe’s and Houzz

By Becky Harris

The sweepstake winners’ master bathroom gets a makeover with a new shower, tile and storage space

Avoid Falling Bottles with a Shower Niche!

By Becky Harris

BATHROOM DESIGN Step Into a Refreshing Outdoor Shower

By Becky Harris

Open Showers Blur the Line Between Inside and Out

BATHROOM DESIGN Outfit Your Shower With the Right Bench for You

By Tiffany Carboni

Whether you want a simple perch or a massive seat in your shower, our guide can help

KITCHEN DESIGN Simple Pleasures: Wake Up and Smell the Coffee

By Laura Gaskill

Slugging down any old sludge while pulling on socks is no way to start the day. Learn to brew amazing java and savor the experience here

Sponsored

More Discussions

cleaning cement splatters from painted metal window frame

2

So many regerts

54

Possible issue (workmanship) in new home build?

25

Need serious advice please

3

Gutters or Metal Diverters?

6