Rain should deliver a crisp, mineral scent to the atmosphere. But for some homeowners, it brings something much less pleasant — a clear sewage odor in their home. If you’ve ever thought, “Why does my house smell like sewage when it rains?, you’re not alone. This problem isn’t as unusual as you might imagine, and while it’s no picnic, it’s also solvable.
Why Rain Causes Sewage Smell in House
WebMD explains that to understand why your house smells like the sewer during rain, you first have to understand the science of sewer gases, and how weather affects your plumbing system.
The Science Behind Sewer Gas
Sewer gas is a mixture of gases, including hydrogen sulfide, methane, and ammonia. These gases occur naturally when organic waste breaks down in your plumbing system. While they are usually trapped in your pipes, when they are released, as during a rain, they leak into your home.
The barometric pressure rises or falls when it rains. This draining can push sewer gases back out through your drains, especially if your plumbing system has preexisting problems. Rain also raises the humidity in your home and pipes, which can make the smell worse.
Why People Smell Sewage After It Rains: Some of the Usual Causes
Now that you know why rain can cause a sewage smell, let’s take a closer look at the most common culprits.
Clogged Bacteria in Plumbing Systems
Heavy rain can stimulate the release of stronger odours from organic waste buildup in your pipes. The smell gets worse during rainfall as the inside of the pipes become more humid, providing perfect conditions for bacteria. Over time this waste can build up and compound the problem.
Issues with Septic Tanks
If your house utilizes a septic system, rain water from the rainfall can seep in to the septic system making it over flow or drip. This can cause sewage odors to leak into your home. Here are 5 signs of a failing septic tank:
- Sinks or toilets that are draining slowly.
- EducationPersistent gurgling sounds from your pipes.
- A powerful sewage smell hovering around your yard.
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Dry Water Traps (P-Traps)
P-traps & Water traps Like P-traps, water traps are there to help keep sewer gases from coming into your home. These work by keeping a small portion of water in the curve in the pipe to act as a blocker. But if a drain isn’t used often, the water can evaporate, causing the trap to dry out and allowing sewer gases to escape.
Broken Pipes and Root Intrusion
Pipes also become cracked or leak over time with use. Especially during heavy rains, tree roots will absorb more water and invade your plumbing system. These structural damages can discharge sewer gases into your home.
Onset Of Rainstorm → Change In Air Pressure
Low atmospheric pressure during rainstorms sometimes confuses the normal flow of gases in your plumbing system. This change can push the sewer gases back into your home through drains, causing that distinctive sewer odor.
Health Risks of Sewer Gas Exposure
In addition, sewer gases are unpleasant and if you are liable to be exposed to them over a long period they can be very unhealthy. Here’s what you need to know:
- Hydrogen Sulfide Poisoning: This gas gives off the odor of rotten egg, but in high quantities it can lead to headaches, dizziness, nausea, and lungs issues as well.
- Methane Risks: Methane is colorless and odorless but a highly flammable gas. Although it’s less likely to make us ill directly, it represents a fire hazard.
- Other Symptoms: Long-term exposure to sewer gases can lead to exhaustion, breathlessness, and even unconsciousness.
If you or a family member experiences any or all of these symptoms, it’s important to take action on the sewage odor due to the dangers of sewage gas exposure.
Ways to Deal with It: DIY Solutions to Treat the Sewage Smell
You don’t need to immediately call a plumber. Here are a few do-it-yourself solutions to try for eliminating the sewage smell:
Cleaning and Flushing Drains
One of the most common causes of sewer smells is complementary residue in your drains. Here’s how to clean them:
- You sprinkle baking soda in the sink, then pour vinegar.
- Then let the mixture stand for 15–20 minutes.
- Rinse with hot water to remove debris and bacteria.
This natural remedy cleans your pipes and deodorizes.
Rehydrating Water Traps
Rehydrating your P-traps is easy if they have dried out:
- Flow water down unused drains, such as those in guest bathrooms or laundry rooms.
- To toilets, flush, making sure the traps are charged with water.
Inspecting for Visible Damage
Look for cracks or leaks on visible pipes under the sink or around drains. If you see damage, you might use plumber’s tape to temporarily seal the leak until a pro can take care of it.
When to Contact a Professional Plumber
At times, Do It Yourself solutions aren’t sufficient. Here’s when it might make sense to call in a pro:
Bad Smell But No Crack or Entry Point
If, after attempting DIY remedies, the sewage smell persists, it may signal a more complicated issue, such as a cracked pipe or a septic tank problem.
Septic Tank Inspections
If you suspect that your septic tank is the source, get it inspected by a professional. Maintenance on a regular basis will help prevent overflows and leaking.
Advanced Plumbing Repairs
Professional plumbers can undertake repairs for large-scale problems such as tree root intrusion or badly damaged pipes, including the work of pipe relining or replacement.
How to Prevent Sewage Smells During Rain
An ounce of prevention is worth a pound of cure. Here’s what you can do to prevent that sewage smell from happening again:
Regular Plumbing Maintenance
Book yearly checks with a certified plumber to find and fix problems early on.
Backflow Prevention Device Installation
These devices stop sewage and gases from entering your home when heavy rains are causing flooding.
Proper Drain Usage Practices
Do not pour grease, food waste or other debris down your drains. These items can clog your pipes and can lead to odors.
FAQs
Why does my house smell like sewage only when it rains?
Rain alters the air pressure, potentially pushing sewer gases back into your home through drains. It can also worsen existing plumbing problems, such as clogged pipes or a failing septic system.
[Read more: Can sewer gas exposure make you sick?
Yes, long-term exposure to sewer gases can lead to health problems (headaches, nausea and respiratory issues). In extreme instances, it can cause hydrogen sulfide poisoning.
Why do I know if my septic tank is failing?
Signs of a failing septic tank include slow drainage, gurgling sounds and consistent odors after raining. Routine checks can catch problems early.
Conclusion
A sewage smell in your home when it rains can be frustrating and unpleasant, but it is not something you need to tolerate. You can get rid of the odor and keep it from coming back by understanding the causes, tackling the problem with DIY solutions, and getting professional help when needed.
As always, remember that regular upkeep and preventative measures are vital to maintaining a scentless home. If the smell doesn’t go away, or you suspect a larger problem, don’t hesitate to contact a professional plumber. It’s worth it for your health and comfort!
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