Problems sealing wastes on vanity basins

[Vicdiy]

I have recently fitted three vanity basins at my daughter's house and in every case have had a problem sealing the waste to the basin.I have used the washers supplied without sealant and all three have leaked. To remedy it I used Basin Mate ( I think that's what it's called) which basically is a thick tapered rubber washer which forces itself into the hole between the basin and the waste fitting on two of the basins and on the third I put plenty of Plumbers Mait between the washer and the waste.My theory as to why they all leaked initially is that water gets into the overflow slot,it then runs down the thread and the washers supplied are not tight enough against the waste to stop it running down.The Basin Mate is really tight because when it is tightened up with the big waste nut,it is tapered and is forced against the waste thread and the basin.Similarly the Plumbers Mait essentially does the same job because it is filling the gap between the threads of the waste and the basin. Am I correct in my thinking that this is the reason they all leaked initially and that unless the washers supplied with the waste are really tight against the threads then they will not seal without some form of sealant or the use of a Basin Mate washer.

 

[Gasmk1]

yes i had same problem when changing mine couldnt find my plumbers mait so got a basin mate

 

[Harvest Fields]

You need a seal/sealant between where the plug goes and the basin also.

 

[Vicdiy]

You need a seal/sealant between where the plug goes and the basin also.

I did have a seal there but I don't think that was where the problem was as it was a good seal in all cases

 

[Harvest Fields]

I did have a seal there but I don't think that was where the problem was as it was a good seal in all cases

What did the waste instructions say to use?

 

[Vicdiy]

What did the waste instructions say to use?

They had a washer above the basin and a a washer below and simply said use these with a diagram showing,no mention of anything else.

 

[Harvest Fields]

They had a washer above the basin and a a washer below and simply said use these with a diagram showing,no mention of anything else.

Try silicone in both areas most waste instructions now have an arrow saying put silicone here and here

 

[Vicdiy]

Try silicone in both areas most waste instructions now have an arrow saying put silicone here and here

Do you think my theory about the water getting into the overflow slot and running down the thread is correct?

 

[Harvest Fields]

Sounds like it.

 

[Scott_D]

Silicon needed.
If it's really bad I also put a few wraps if PTFE where the bottom nut sits

 

[ShaunCorbs]

I always bin all the rubbers and use plumbers mate in sausages

 

[Vicdiy]

I always bin all the rubbers and use plumbers mate in sausages

I think you are right I did this years ago and it worked fine.Plumbers Mait seems great to me, unlike silicone you can run the water straight away to see if it has sealed I struggle to see why everybody doesn't use it.I think I got sucked into thinking that if the washers are provided for that purpose then they should work. I should have used my instinct.

 

[Harvest Fields]

Depends on the make of silicone used.

 

[Ben-gee]

Plumbers mait sausages with a dob of silicone and a smear of flux, mmmmmmmmm tasty.

 

[Vicdiy]

Depends on the make of silicone used.

Do you mean that you can use Plumbers Gold and run water on it before it has set?

 

[Ben-gee]

Throw away any foam seals. For inside basin use silicone ; underneath use the rubber washers provided (and/or fibre) and augment this with silicone too. It will not leak.
This is what I do when fitting a bathroom and therefore there is no rush to test/use the basin. If I’m just changing a waste and so need to test and go immediately, do exactly the same thing but use Stixall or CT1 in place of silicone.

 

[Harvest Fields]

No I mean if you use a silicone that can be applied under water you can.

 

[Vicdiy]

Throw away any foam seals. For inside basin use silicone ; underneath use the rubber washers provided (and/or fibre) and augment this with silicone too. It will not leak.
This is what I do when fitting a bathroom and therefore there is no rush to test/use the basin. If I’m just changing a waste and so need to test and go immediately, do exactly the same thing but use Stixall or CT1 in place of silicone.

But if you use Stixall won't it be impossible to get it off again in the future.

 

[Ben-gee]

Nothing is impossible to a proper plumber mate, some things just cost a bit more to do!

 

[Phil]

Grips and twist the sucker off, its getting the pedestal out thats the problem if the basin has been glued ti tiles...i had one and the idiot had used expanding foam to weld it ti the tiles...i spent all evening with a steel ruler and a blowtorch to try and melt through to no joy. I did manage to fill the house with fumes though.

 

[Ben-gee]

Stuggled with a ped for ages once until I realised it was bolted to the basin via a kindof close-coupling plate fitted to the waste fitting - I think it was an Ideal Standard. I have since come across this 6 or 7 times, I think it was a "thing" for a while.

 

[ShaunCorbs]

Stuggled with a ped for ages once until I realised it was bolted to the basin via a kindof close-coupling plate fitted to the waste fitting - I think it was an Ideal Standard. I have since come across this 6 or 7 times, I think it was a "thing" for a while.

Old school probably find the basin is on a chair bracket also