Leak behind pedestal basin All aspects of plumbing questions and answers, help, tips and information

[Calculus]

I have a standard pedestal washbasin which is leaking from the wastepipe. Looking down the plughole reveals the problem. Sealant between (I think) the wastepipe and part of the sink below the plughole has come out. I can't examine it properly as the pedestal is in the way, so my first question is, can I assume the sink is firmly attached to the wall or do I need to support it when I remove the pedestal? If so, how? A chair on each side perhaps? My other question is what will I need to do the job? The plastic U-shaped wastepipe looks like the sort of thing I can get at B&Q, but will anything else need replacing, e.g. peering round the pedestal I can just make out a black rubber seal right at the top which suggests there is a separate piece of piping or hardware sitting between the basin and the plastic wastepipe. Also what do I use for sealant and should I get it in a tube or pot or something else?
Hope someone can advise on this!

[nitro23456]

the pedestal supports the sink, even though the sink will be screwed to the wall it is not sufficient to remove the pedestal - the sink would fall immediatley.

You can normally work with the pedestal in place though. The first part of the waste is the plug hole which will go through to the underside of the sink where it terminates in a 32mm thread. Ti this thread a 32mm bottle trap is normally screwed onto it... there should be a rubber washer between the bottle trap and the thread of the plughole waste.

Buy a new bottle trap (32mm for a sink) which will come with the new rubber washer. Unscrew the old one leaving the plughole and thread intact and screw the new onto it using some PTFE tape on the thread if required.

Easy job 5 minutes.

[Calculus]

Nitro23456,
I just love the 'easy job, 5 minutes'! You're talking to a man who takes a day off work to put up a shelf! Thanks for the plan of action.

[nitro23456]

Just to add this is likely what you need:

http://www.awin1.com/awclick.php?mid=12 ... AP-_-15739

You can see the black rubber washer at the top next to where the compression fitting screws onto the sink waste outlet thread.

Once these start leaking they are hard to stop so you may as well replace the whole lot for £3!!

It is possible that your current one maybe push fit at the other end where it connects to the piping and not the compression fit as pictured.... this shouldnt be an issue.