P-traps are typically made from:
Bonus tip: Older homes sometimes used S-traps, which loop downward in an “S” shape. These are no longer allowed by code because they siphon dry too easily, causing sewer smells. P-traps replaced them as the safer, modern standard.
The P-trap uses a very simple physics principle: water blocks air.
Here’s what happens each time you run the faucet:
A P-trap can stop working if:
P-traps aren’t just under bathroom sinks — they’re everywhere wastewater leaves a fixture.
These are the most visible and the easiest to service.
You won’t see these traps, but they’re there — hidden under the floor or inside the framing.
Washing machines and some dishwashers connect through systems that rely on a plumbing trap to prevent sewer odors.
Yes. Building code requires every shower to have a functioning P-trap.
Why it matters:
If you smell sewage near a shower, the trap may be:
Yes, but not the kind you see under a sink.
A toilet has a built-in P-trap molded directly into the porcelain bowl. This is why water always sits in the bottom of the toilet — that’s the trap seal preventing odors.
Because toilets have their own internal traps, they do not use an additional trap in the floor line.
Even though P-traps are simple and reliable, a few issues come up again and again in Albuquerque homes. The most common include dry traps, leaks, cracks, clogs, and installation mistakes. Knowing the signs early helps you avoid sewer odors, water damage, and costly repairs down the line.
A P-trap needs water to seal out sewer gases. When a sink, shower, or floor drain isn’t used regularly, the water in the trap slowly evaporates. Once the water seal disappears, nothing stops those sewer gases from creeping into your home.
Leaks are the second most common P-trap issue. They typically occur from:
Because the trap sits under the sink, leaks often go unnoticed until they’ve caused damage.
Even small, slow leaks can cause rot, cabinet damage, mold growth, or a broken trap seal — allowing sewer gases into your home.
Clogs form when debris builds up inside the bend of the trap. For sinks and showers, this often includes:
Wire-hanger-style DIY methods can scratch the inside of the pipe, creating rough surfaces where future clogs form even faster.
Best Solution
Have a licensed plumber safely remove and clear the trap, check the rest of the drain line, and ensure no deeper blockage is forming.
A full replacement may be needed if:
New PVC or ABS traps are durable, affordable, and handle moisture better than old metal ones.
Routine drain cleaning and periodic plumbing inspections help catch issues early. A plumber can confirm:
This type of maintenance protects your home from both sewer odors and long-term water damage, especially in older Albuquerque neighborhoods with aging plumbing.
If you’re dealing with sewer smells, slow drains, leaks under the sink, or recurring P-trap issues, the safest move is to call a professional. A licensed plumber can diagnose whether the trap is the problem or if something deeper is happening in your drain or vent system.
At B. Carlson Heating, Air Conditioning & Plumbing, our expert plumbers handle everything from clearing clogs to replacing damaged traps to fixing underlying venting or drain issues. We’ve been helping Albuquerque homeowners stay safe and odor-free since 1971 — and we’re available 24/7 when you need us most.
If something doesn’t smell right or drain right, call B. Carlson right away.
