How to Get Rid of the Sewage Smell Coming From Your Shower Drain

You’re in the shower shampooing your hair, and suddenly you catch a whiff of something unpleasant. Something that smells like sewage. Your first instinct is that it’s coming from the toilet. That might be true, but it could also be coming from your shower drain. Here are a few examples of what could be behind the stench, and how to get rid of it.

How to fix the sewer smell in your shower drain

There are a few potential sources of the sewage scent that’s emanating from your shower, tub, or sink drain. Because drains aren’t out in the open, it often takes some trial and error to figure out what needs fixing to get rid of the smell. Your best bet is to start with the easiest solution and go from there.

Clogged drain

Sometimes it’s obvious when your drain is clogged. Other times, a drain may appear to be functioning, but in reality, it’s getting close to capacity and a blockage.

If you’ve never had the privilege of cleaning a shower drain before, then you may be wondering how it could be the cause of the sewage smell. In that case, buckle up: Things are about to get gross.

Sure, there’s probably a lot of hair down there, but the foul odour usually comes from the bouquet of other slimy gunk trapped with it: Dead skin, bacteria, soap scum, body oils, debris, biofilm, and anything else you put down your shower drain.

Lifehacker has published several posts over the years on unclogging drains, so take a look at the different methods, and pick one.

Dry or dirty P-trap

A P-trap, or drain trap, is a U-shaped section of pipe that holds a small amount of water at all times to help prevent sewer gases from coming up through your drain. So when P-traps dry out, it could make your bathroom smell pretty disgusting.

This is most common in showers that are rarely used — like one in a guest bathroom — or that haven’t been used for a while, like if you’ve been out of town for a longer period of time. If that’s the cause of the odour, running the shower for about a minute to refill the pipe should do the trick.

On the other hand, if you use the shower on a regular basis, the P-trap could be dirty. To clean it, pour one cup of hot water down the drain, let it soak in for a minute, and then pour one cup of undiluted chlorine bleach down next. Let it sit overnight, and by the next morning, your P-trap should be clean, sanitised, and odour-free.

If you try both methods and suspect the smell is coming from your P-trap, it may be broken. In that case, you’ll need to call in a professional.

Leaky pipes

If neither of the solutions above worked, you may be dealing with leaky pipes in your walls or under the shower. Wastewater from the shower and/or sewer gases could be escaping through cracks or damaged connections in the pipes, and cause your bathroom to smell like sewage. Finding and fixing the leak is a more complicated project best left to professionals.