08/28/2026
We run into these almost every week when we're out servicing older homes along the Wasatch Front.
Somebody buys a home built in the '70s or decides to finish their basement that's been sitting since 1985, and there it is: a classic S-trap sitting right under the vanity.
Here’s the deal with why plumbing code banned S-traps back in the eighties: Whenever you drain a full sink of water, that steep drop creates a siphon effect. It sucks all the water right out of the pipe curve. Without that standing water acting as a seal, sewer gas creeps right up through the drain and into your living space.
If your basement bathroom always smells a bit funky no matter how hard you scrub, an S-trap is usually the main culprit.
Fixing it isn't a massive ordeal. We take out the old setup, install a proper P-trap with correct venting, and keep those sewer fumes out for good.
Got an old setup under your sink you want us to look at? Give Sharp Water Solutions a call or send us a text. We'll get it squared away for you.
-Trap