Home Improvement--General/bathroom sink


I recently purchased and had someone from the store installed a vanity.somehow there is a hole the size of a coin at the bottom of the sink (outside).There is another hole on the side of the sink (I believe is to help water drain faster). Sometime water will go thru this top hole and drop onto the cabinet from the bottom hole. What is this bottom hole for? Is this a defect?
Thank you so much for your help!
Best regards,


There should be a drain hole in the very bottom of the sink with a drain line attached to it.  There should also be a small coin sized hole on the inside of the sink near the top.  This hole opens into a cavity between the inner and outer walls of the sink. This cavity empties into the same drain line attached to the bottom of the sink.  The purpose of the hole is to prevent the sink from overflowing if the drain is plugged and the water is left on.  Water would then flow into the hole near the top of the sink and pass into the drain below the sink plug.  

The sink itself should not have any other hole in the outside wall.  If the bottom hole is in the side of the drain pipe, this is where the drain plug linkage should have been attached.  Attaching the drain plug linkage hardware is part of the installation process and should have been done at the time of the install.

Hope I have been of some help in this matter.

Best regards,

Home Improvement--General

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Tony Wood


I can answer a wide range of home improvement and maintenance questions. My expertise is in carpentry, painting, framing, siding/boxing, doors, windows, decks and screen and glass enclosures. Wood's Home Maintenance Service


I am a life time resident of North Carolina with over 30 years experience in multiple facets of the industrial, commercial and residential construction industry. For the past 23 years I have owned and operated Wood's Home Maintenance Service , providing services primarily in Johnston, Wake and Sampson Counties of North Carolina.


Several Home improvement articles published on Angie's List and other online forums.

High School graduate ~ proficient in CAD (computer aided design), Open Office program suite.

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