Bathroom sink overflow opening effectiveness


Consider an extreme situation: a fully opened faucet and a completely closed pop-up bathroom sink drain. Should a properly installed overflow opening actually prevent the sink overflowing? Or it is supposed to just help the main [open] drain by lowering the about to overflow water level down faster?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Is this a vessel sink?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No, it's a "regular" one but the spring-loaded pop-up drain that was included with the sink has been replaced with the handle-operated one that came with the faucet. It could be that the internal cut (within the pop-up body) that is made to accommodate the overflow stream is partially blocked...
What is the practice of marrying the sinks with overflow openings with "non-native" pop-up assemblies to avoid such obstructions?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

most anti flood holes dont accept the full flow from a faucet with a fully blocked drain./
i looked into this many years ago when replacing my bathroom sink
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

pop-up closes. Therefore if the pop-up is open and the drain is not draining to the point the water backs up to the overflow, you are probably out of luck since the blockage is probably beyond (down stream) from where the overflow would connect.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I would NOT expect the overflow to keep up with a fully opened faucet. Certainly not a good idea to run a faucet full blast and leave the room.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

In the old days, a fully open sink faucet could overwhelm the sink overflow (I did the experiment in more than one sink)
but with the mandate for "low flow" faucets I'm guessing that overflows might now handle the flow.
cheers Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.