Hi all, I’m struggling with a leak from our bath waste. The original fitter sealed everything up with about a tonne of silicone, which is now failing.

The underlying problem seems to be the fact the bottom of the bath isn’t completely flat, which means the rubber gasket seal does’t sit flush with the underside of the bath. I’ve tried making a thicker seal out of a sheet of 6mm silicone rubber but it’s still not sealing.

I think the waste hardware is a bit cheap and nasty, so I was going to try this decent looking one from screw fix click here

Thought I’d ask for hints & tips before I strip everything out and replace.

I was considering plumbers mait but I gather that’s frowned upon for baths because of the movement…

rubber gasket seal does’t sit flush with the underside of the bath

probably just needs the brass ring nut tightening moreso.

No, it’s very tight already and I don’t want to crack anything. Putting the gasket against the bath as flush as I can still leave a 1-2mm gap about 20mm long on one side

when you say gasket, you mean big rubber washer yes?

Yes the big black rubber washer in between the underside bath floor and the plastic waste drain that connects to the trap.

The plug/waste design is a centre screw that I tighten from above (i.e. from inside the bath)

Silicone it on, bead on base of waste fitting, then the washer, preferably thickish rubber variety, then more silicone, tighten up, run finger round to smooth joint and force into gaps left by irregular shape of bath, being careful not to get fibre glass splinter, leave to cure a good few hours, then test.

Wastes into sanitaryware are a nightmare and we always make them in with silicone as nothing is ever flat……

aha.

this style, yes?

being careful not to get fibre glass splinter

*shudders*

Yes Stoner – that’s the one. Seems much more likely to fail than the below design. Plus it’s a bugger to tighten up and keep straight because you can’t hold the waste pipe whilst tightening

Plumbers mait then: where would i apply it? All sides of every surface then assemble, tighten and wipe off excess?

Plumbers mait is horrible stuff, should be banned, also not suitable fro use on acrylic baths I seem to remember.

Well – problem solved. I’ve spent ages thinking of ways to seal the uneven surface. Then I just realised I should make it even! 20 secs with a Black & Decker sander levelled the surface off, and everything sealed perfectly and no drips when draining a full bath.