We’ve all experienced it - that dreadful, sour smell wafting from the bathroom that can only be described as sewer-esque. You lift the toilet lid with hesitation, fearing the worst, only to find nothing out of the ordinary.
But no matter how many air fresheners you spray, the stench refuses to budge. If this foul odour has been plaguing your bathroom, you’re not alone. Smelly bathrooms are one of the most common plumbing issues homeowners face. But identifying the underlying cause can seem like hunting for a needle in a haystack.
In this blog post, we will walk through the most typical culprits behind bathroom sewer smells. We’ll explore issues with drains, pipes, ventilation and beyond. You’ll learn a process to diagnose the source of the odour methodically.
Once the cause is pinpointed, we’ll offer solutions tailored to properly treat a sewage smell stemming from drain problems, ventilation deficiencies or septic system malfunctions. By the end, you’ll know to banish bathroom baddies back where they belong - and reclaim your fresh fragrance once more.
Common Causes of Foul Bathroom Odours
Several potential culprits can lead to a sewer gas smell emanating from your bathroom. Understanding the most common sources is key to properly identifying and addressing the issue. The top offenders typically involve drains, pipes, and ventilation problems.
Drain and Pipe Issues
Clogged drains
When you have a full septic tank, the smell of sewage is not all that you will notice. Signs of a clogged drain include slow draining, gurgling noises or standing water in the sink or tub. Pouring boiling water or using a drain-cleaning snake can dislodge buildup. Be careful of toxic drain cleaners.
Broken traps
If you experience a sewer smell after heavy rainfall, it could result from sewer backup. During heavy rains, the excess runoff water piles pressure on the city’s sewer system, causing a sewer’s backflow into individual lines. Check under sinks and toilets for cracks in the curved section of the P-trap pipe. Replace any broken traps to prevent sewer gas backflow. Traps should also be filled with water daily to maintain the seal.
Corroded or cracked pipes
Pay attention to rust marks or weakened areas in visible pipe sections, especially around joints. Gently tap pipes with a wooden spoon to listen for hollow, thinned areas that require repair or replacement. Signs of leaks or damp spots on ceilings and walls below also indicate cracks underground.
Older plumbing systems
Homes with cast iron, galvanised steel or other ageing materials are at higher risk. Contact a plumber to inspect hard-to-reach areas with a camera snake to catch all issues early before they worsen. Re-piping may be best for extensive corrosion.
Improper pipe support
Without sturdy hangers securing pipes in place, constant vibration can cause joints to weaken over decades. Check hangers are intact and pipes aren’t excessively swaying, which leads to strain and splitting.
Ventilation Problems
Poor airflow
Check bathroom fans are unobstructed and drawing air out. Ducts should vent directly outside, not into the attic, where odours recirculate. Open windows when showering to allow cross-breeze.
No exhaust fan
Exhaust fans are crucial to remove moisture-laden air where odour bacteria thrive. Lack of fan circulation lets smells permeate.
Old ventilation system
Inspect duct interiors for debris that cuts effectiveness. Clean with a brush or vacuum attachment inserted from the roof or window vent. Replace dampers and louvres that don’t fully open or close.
Undersized fans
Small or underpowered fans can only sufficiently change out some air. Measure fans versus bathroom size to ensure proper air changes per hour.
Lack of supply of air
Stale indoor air needs replacement from somewhere. Ensure adequate crevices are under doors for fresh air intake to balance the fan exhaust.
Improper duct routing
Ducts running near heat sources like furnaces or water heaters allow condensation or corrosion inside ducts that harbour smell over time. Reroute problem sections for drier airflow.
Other Potential Issues
While drain or vent pipe issues are most prevalent, a few other factors can also contribute to lingering sewage gases. Understanding these uncommon scenarios helps with properly diagnosing hard-to-pinpoint odours.
Mould or mildew growth
High-humidity environments allow surface mould and mildew to thrive, especially behind shower curtains and around tiled areas. Certain species produce foul odours that seep throughout the bathroom.
Improper cleaning products
Applying corrosive cleaners for toilets onto other surfaces like grout, caulk, or natural stone can damage protective coatings over time. Behind-the-scenes erosion releases sewer gas trapped in porous materials.
Neighbourhood sewer lines
In rare cases, broken lines underground beyond your property can seep gases that enter through foundation cracks or floor drains. Contact the local utility department if widespread odours make the cause external.
Outdated plumbing traps
Older 1-inch drain outlets aren’t adequate anymore, and a newer 1.5-inch plumbing system is recommended. Undersized lines burble more air upwards from the sewer system. Retrofit with proper-sized traps for lasting protection.
Insufficient ventilation
In bathrooms opening to other living areas, the lack of a shut door allows odours to permeate further. Close the door while showering or bathing to contain smells locally.
Identifying the Source of the Smell
If you notice a sewerage smell in your bathroom and minor flooding when taking showers, you could be dealing with a clogged shower drain. Pinpointing where bathroom odours originate can sometimes feel like searching for a needle in a haystack. The key is to check each potential cause one by one methodically.
Start by inspecting visible drainpipes and traps under sinks for cracks, paying close attention to joints and hangers. Then, run water down drains and listen for abnormal gurgling that could signal a clog.
After thoroughly ventilating the bathroom for at least 30 minutes by opening windows and running the fan, re-check key areas for lingering sewage smells that may reveal inadequate ventilation as the culprit. You can also do a simple drain test by lightly covering sinks and the tub when not in use to block odours if they’re still noticeable, isolating a drain issue.
Notify neighbours if sewer gas persists, as the possible cause may lie beyond your property line. Narrowing down suspicious areas lets you dive deeper with special tools to pinpoint the precise source of that pesky sewer smell for good.
Getting Rid of the Sewer Smell for Good
Once you’ve identified the root cause of sewer odours in your bathroom, it’s time to implement a lasting solution. For drain-related issues, thoroughly clear any blockages with a plunger or drain cleaners and replace damaged P-traps.
Clogged ventilation systems require professional cleaning to restore optimal airflow. Corroded pipes may need sections cut out and replaced using proper materials.
Improving general ventilation through adequate exhaust fans and openable windows prevents future bacteria buildup. For signs of mould or mildew, thoroughly clean with a bleach solution and improve humidity control.
If neighbourhood sewer lines are the culprit, contact officials to address repairs. With these targeted remedies, plus maintaining clean traps, annual drain flushing, and running fans after moisture-heavy activities, you can say goodbye to those bathroom ghosts for good. Regular maintenance will give you continued protection from odours down the line.
Preventing Future Odours
Since you’ve banished odours from your bathroom, keeping them away for good requires diligence. First, be sure to thoroughly ventilate the shower drain or baths by running the exhaust fan for 30 minutes to extract harmful moisture.
Next, flush each drain weekly with enough water to empty old residue that can harbour bacteria. Sanitise the toilet bowl, shower walls, and other surfaces periodically with a disinfectant to stunt mould growth.
Also, pour a cup of baking soda down drains each month as a natural deodoriser. Check P-traps under sinks containing water weekly to maintain their seal.
Look for any new signs of potential issues like corrosion or ventilation blockages. Lastly, get drain inspection cameras fully rigged pipes annually, especially in older homes prone to deterioration. Adhering to basic preventative habits makes it highly unlikely sewer smells will plague your bathroom again anytime soon.
Don’t Let Foul Odours Rule Your Bathroom
With any luck, by now, you’ve identified the culprit causing those pesky sewer smells in your bathroom and implemented the right solution based on the troubleshooting steps outlined. Hopefully, those foul odours are a thing of the past!
But if you still need to figure out the cause or need assistance with repairs, feel free to contact the plumbers at Fixed Today. With our expert diagnosis and a full suite of plumbing services, we can thoroughly investigate the issue and get your bathroom smelling fresh again.
The professionals at Fixed Today have the experience to pinpoint problems and remedy them promptly. Give us a call today to discuss your bathroom odour concerns - we’re ready to help you find relief.
