water leak from base of bathroom sink

[hughwon]

I seem to get water leaking from the bottom of my bathroom sink, it only seems to happen say when I have basin full of water to have a wash then when I pull the plug there seems to be water dripping from the base of sink onto floor, I cant seem to work out where the water is leaking from or how it just seems to leak when I pull the plug. I even had a bath once and when I pulled the plug water seem to be leaking from the base of the sink but it does not seem to happen all the time, Can anyone explain to me what is happening and what I can do to stop it. I am not a experienced plumber.

 

[lame plumber]

half fill the basin and see if it still leaks, if it does get a plumber to reseal the waste. otherwise its overflowing

 

[village idiot]

either the oveflow is not properly done or the base of waste (part that is screwed underneath to sink, big nut like dat) has not been done up properly (like simply adding a sealing compound of some sort).

 

[PlumbBobBob]

sounds like there is no seal round the waste where it exits the basin, and water is escaping through the overflow holes in it.