I've never seen bathroom sinks without an overflow hole in my area (California). I've also never detected any lingering smell, not ever.

When something smells, it's dirty. Maybe it's coming from the trap? For sink smells, there's nothing that a good dose of bleach in water won't fix. If you think it's coming from the overflow area, make sure to give it a good splash of the solution.

Edit for PS -

Are you sure the smell is coming from the sink? If it smells like sewer gas, the problem isn't the sink (unless the trap is dry).

This post was edited by snidely on Wed, Dec 24, 14 at 13:02

I noticed that the cultured granite sink options from our builder did not have overflow holes.... I questioned it and was told it was an option. I do worry about my kids overflowing the sinks. I know at the home stores many of the cultured sinks do not have overflows...so I suspect it is not code.

Merry Christmas - and thanks for your replies! :)

I should probably explain that I have a very strong sense of smell - unnaturally strong - so this may be a smell that no one else notices. However, I have noticed weird smells coming from the sink overflow holes in 3 different houses. These were other people's homes, so I can't try the bleach trick to see if that fixes it. We live in a temporary rental house that was constructed 6 months ago, so the overflow holes haven't had a chance to start stinking quite yet.

I primarily notice the smell when I bend down over the sink to brush my teeth or wash my face, but I've also smelled it when standing upright. It seems to happen mostly when the faucet is running, perhaps when the water pushes air out of the overflow hole (assuming that's possible).

I've wondered the same thing about the cultured marble sinks - if code requires an overflow hole, why don't those sinks have one?

We don't have kids, so I don't have to worry about them overflowing the sink. If the plumbing code absolutely requires an overflow hole, I believe there are overflow plugs I can purchase, but I'd rather just avoid the overflow hole to begin with.

Does anyone happen to have access to the 2012 IPC?

"I should probably explain that I have a very strong sense of smell-unnaturally strong"

Me too ! That's the negative, the positive is that a sensitive sniffer also produces a heightened sense of taste, which I enjoy having. I can name ingredients used in food that others don't even notice.

We replaced 5 bathroom sinks (with overflow holes) a few years ago - they were 40 years old - never had odors from any of them. They were also well cleaned weekly.

Good luck to you, I wouldn't worry, I think this "problem" is more imagined than real.

Unfortunately, a chronic health condition has caused my ultra-sensitive sense of smell, but it has not been accompanied by a heightened sense of taste. If anything, my taste buds are "duller" than they used to be.

I wish this problem was more imagined than real - doing a quick Google search produces tons of complaints about this. I know there are probably ways to get rid of the smell, but I would rather just prevent it altogether by eliminating the overflow holes. If that's not possible, I will survive - but I would like to find out whether I even have the choice. I plan to contact the building department in the new year, but I was hoping to have some "ammunition" from the plumbing code first. Still crossing my fingers!

Kitchen sinks do not have the overflow holes. I am unaware of any code provision requiring any such overflow provision. But the overflow passages in bath lavatories ALWAYS drain out just above the water level in the fixture trap, immediately below the drain stopper. Thus the drain itself in the sink exudes exactly the same odors/gas, if any, as does the overflow drain holes.

This post was edited by bus_driver on Sun, Dec 28, 14 at 14:25

To prevent overflows in a sink that does not have an overflow hole, consider a sink drain cover that is made for vessel sinks or other sinks that don't have overflow holes. Duravit, Kohler and Grohe make these to name a few. I have them in one bathroom where there is no overflow hole. What the cover does it prevent you from filling the sink with water but I prefer the protection from a flood.
Good luck!

Kohler Pop up Drain assembly for sinks without overflow.ÃÂ

Here is a link that might be useful: Kohler Pop up Drain assembly for sinks without overflow

Decided to replace the brass flange on my bathroom sink. removed the corroded flange, screwed in the new flange but now there is a leak thru the gasket underneath the sink. Don't understand the workings of the overflow holes as the water goes out the overflow holes and not down the drain.

Everything was working before I switched out the flange.