What are these random holes in my sink for?

April 14, 2005 4:22 PM

I've noticed that nearly all bathroom sinks have this : either one or two small holes located near the rim, facing opposite the faucet head. What exactly is their purpose?
posted by invisible ink to Home & Garden (19 answers total)

It's not a drain, to prevent overflow?
posted by houseofdanie at 4:25 PM on April 14, 2005

They are drain lines connected to the main drain pipe, so the sink won't overflow.
posted by Specklet at 4:25 PM on April 14, 2005

It's to prevent overflow.
posted by deborah at 4:25 PM on April 14, 2005

Triple jinx!
posted by Specklet at 4:29 PM on April 14, 2005

Plug the sink's bottom drain and find out!
posted by scarabic at 5:18 PM on April 14, 2005

How could you have made it to age five and not been curious about that? Or, do you come from somewhere where they don't have them?
posted by ParisParamus at 5:36 PM on April 14, 2005

Maybe not the purpose - but when plunging the sink (and the bottom is covered), gunk jumps out through these drain spouts. My uncle told me kitchen drain pipes are a quarter inch wider than bathroom pipes - which may explain why these outlets are not on kitchen sinks.
posted by philfromhavelock at 5:37 PM on April 14, 2005

I think the reason they're not on kitchen sinks is that kitchen sinks typically don't have a drain plug lever thing on the main drain. The presence of these makes it much more likely one will forget that it's in the "plugged" position, and allow the bowl to fill up while one's back is turned.

Other reasons it's in bathrooms and not kitchens (guessing)

• Kitchen sinks are a lot bigger and unlikely to fill up by accident
• bathroom sinks are lower and more susceptible to little kids screwing around

posted by stupidsexyFlanders at 6:09 PM on April 14, 2005

Bathtubs have these too, and when trying to bathe it is so annoying to have the water start draining out on me!
posted by clgregor at 6:31 PM on April 14, 2005

It's an important safety feature but they screwed the pooch on my bathtub. The overflow drain is too low in the tub so I can only fill it maybe halfway. It's not even enough water to fully cover me when I'm in the bath, dammit.
posted by Justinian at 6:40 PM on April 14, 2005

Remember: always "the" dildo, never "your" dildo.
posted by Justinian at 6:41 PM on April 14, 2005

My sinks have that, so this one time when I was going to clean the sink I let it fill with diluted bleach up till that point, figuring to soak as much of the sink as I could - and all the water that went into the hole promptly spewed out from somewhere under my sink. Oops.
posted by TheOnlyCoolTim at 7:17 PM on April 14, 2005

The HalfBakery has a proposal for overflow drains on kitchen sinks. It led me to this official statement, of sorts, from Kohler, that a) the secondary basin serves as an overflow, and b) overflow drains can harbor germs.

Yay for germ-free kitchen sinks, I guess.
posted by dhartung at 10:30 PM on April 14, 2005

clgregor and Justinian: Try this for deeper baths.
posted by teg at 11:23 PM on April 14, 2005

ParisParamus mentions an interesting point : such overflows are unknown in Australia. In nearly forty years, I've seen maybe 3.

Same goes for the pop-up drain plugs that are fairly common in the US. Never seen 'em here.

I don't know why, because I've always thought they were a damn good idea.
posted by Pinback at 11:45 PM on April 14, 2005

I've seen plenty of kitchen sinks with overflow drains in Europe. And yes, they definitely get nasty in the bathroom, which I discovered when I was the kid, mentioned by ParisParamus. Black gook came out of the overflow as soon as the water went in.
posted by Goofyy at 11:49 PM on April 14, 2005

all the water that went into the hole promptly spewed out from somewhere under my sink

my guess is this would be due to a crack in the sink's exterior, as the water from these holes goes down the same pipe as the main drain.
posted by hellbient at 9:31 AM on April 15, 2005

*high fives houseofdanie and Specklet and demands a Coke*

The differences in plumbing in other countries is interesting. It's easy to assume they're the same. I found out baths are quite odd in Britain. Y'all ever heard of a hot/cold mixer? Nice, big tubs, though. Showers, if there is one available, are odd as well.
posted by deborah at 10:12 AM on April 15, 2005

The overflow drain is too low in the tub so I can only fill it maybe halfway. It's not even enough water to fully cover me when I'm in the bath, dammit.

Yes, annoying: You lie there trying to cover the holes with your foot, but they're not easily plugable so the best you can do is cover part/some of them — the water is still draining, just a bit slower and accompanied by that noise like a nine year old try to suck the last drops of a milkshake through a straw.
posted by blueberry at 11:15 AM on April 16, 2005