Leaking basin waste All aspects of plumbing questions and answers, help, tips and information

[trainee laydeee plumb]

Hi can anybody help please? I've just fitted a new basin/taps etc. I sealed the new basin waste between the plastic back nut and the basin with sealant (as it says in all the books and the waste instructions), and I also sealed around the back nut-and tightened it as tight as I could. Put the trap on, put it on the wall, plumbed it in, turned it on......and water is forcing its way thru, between the basin and the back nut.
This has also happened on one I did 2 months ago (however that was a pop up waste and it'd moved (as it seems by
alot of plumbers statements on various forums they're prone to do-it took 2 months to start leaking), so I was asked last week to replace it with a captive waste. Again I put it in and this one I used sealant between chrome part and basin, and plumbers mait between back nut and underside of basin-and thats leaking too!!!
Can anyone please help?? What am I doing wrong???? :oops:

[stoneyboy]

trainee laydeee plumb,
Two areas need sealing with basins - where the nut tightens onto the basin and the threads of the waste. Use a rubber washer between the nut and basin and use silcone sealant between the washer and the basin also use a good smear of silicone on the threads of the waste in the nuts tightened area.
end

[htg engineer]

You shouldn't need anything other than what is supplied with the fitting. If there's no washers then use silicone or putty.

You'll find cheaper plastic wastes (normally supplied with basin/bath etc) are very poor. You'd be best including price of decent waste grate when pricing for jobs and bin the cheap plastic ones.

htg

[trainee laydeee plumb]

thanks to both of you
the washer supplied with the waste isn't great at all-very flimsy. I've taken it all back out, cleaned it up, and re-sealed everything (using loads of sealant!) and it works!! It seems there's no such thing as too much sealant.
Oh and I've taken on board comment about cheap wastes supplied with the basin-next time will def price it up to include a better waste.
Thanks again :D