Required to fix S-traps?

4 Replies

Hi BP'ers! Just purchased a home as a quick cosmetic turn. Some of the fixtures use an S-trap style drain because venting does not exist (its an older home). Am I required to install venting or can I use the S-traps?

Unlikely Plbg. Inspector Is going to grandfather in s traps.  You may be able to use a wet vent for end of line sink fixture provided the main waste it connects to has a 3" main vent thru roof.

@Joe Schaak it really depends on the inspector.  Someone will likely flag it as a problem, likely the buyer's inspector, and the question is whether you will have to fix it.  If the plumbing looks new, they will assume you replaced it and didn't pull permits so that is also something to consider...  I believe you have to be living in the house to pull a plumbing permit assuming you are not a licensed plumber.  Because it is a replacement and not a repair a permit would be required.

A work around that I have used and haven't been questioned on is to run a vent pipe up to the counter and put a vent cap on it.  Essentailly you would have your pipe coming out of the floor, connect to a T, the side of the T would connect to your trap/sink, the top of the T would go up to the counter top (or connect through your sink holes) and install a vent.

I have been burned in the past by using old plumbing without a vent and they have made me run a vent through the roof after a kitchen remodel was complete.  Was easier to take the siding off to get the job done.  From a plumbing perspective we didn't do more than change out the sink and re-connect to the drain.

Of course I am not a plumber, just letting you know my experience.

@John Woodrich Thanks for the reply! I spoke to a St Paul City plumbing inspector. He was very helpful. Unfortunately, the city is requiring ANY S-traps to be removed and a vent stack to be installed for those fixtures. Ugh. Not the result that I was hoping for but good to know moving forward. Hope this helps others as well.

That is the answer plumbing and electrical inspectors always give.  If you touch it you must bring it to code.  If you leave it, it is fine.

Sucks that just changing out a sink can make you bring it to code but it is what it is.