Bath, Sink & Basin - Waste Sealing

[Onoff]

Being the impetuous sort I am I'm asking this question after the event!

 

Had to replace the pop up waste in the old, upstairs en suite. 

 

I ended up with a new, slotted, pop up waste from Wickes as Screwfix were out of them. I dispensed with the single, black rubber washer meant to go under the flange and instead used Sikaflex EBT. Applied a good amount under the flange of the new one and pushed it down into the porcelain. Then, without turning the waste I put the nut on from the underside with just a smear on the nut. All cleaned off with baby wipes and left for a few hours to skin rather than set. Looks good, all neat &  tidy both sides and no leaks.

 

 

I did it similarly on the bath waste following @Nickfromwales advice and I've had no issues with that.

 

So impressed with the product and process I'm going to redo the badly done (by me) kitchen sink waste some time. Sikaflex is simply imo a better product than ordinary "silicone". Odd to describe if you've not used both, it just seems "thicker",  maybe less likely to slump and be squeezed out of where you want it to stay. It almost has washer like qualities on it's own.

 

BUT...reading the Sikaflex EBT data sheet it says to "use a mould resistant silicone for final sealing of sanitaryware".

 

???

 

sikaflex-ebt.pdf

 

Should I be running a bead of something else afterwards?

 

 

 

Edited October 1, 2017 by Onoff

[Jeremy Harris]

The basin in our old house bathroom has had a Sikaflexed in place waste for around 7 or 8 years now.  I ended up resorting to using Sikaflex because the rubber seal just wouldn't bed down properly and seal.  The basin "counter bore" where the waste fitting goes was too shallow (Victoria Plumb crap again......).  In my case, I applied a bead of Sikaflex around the thing, did as you did and stopped the waste rotating whilst I lightly tightened the nut, wiped it all clean with some IPA and left the Sikaflex to go off over night.  The nest day I tightened the nut up properly and fitted the trap.  It's never given any trouble, and stays cleaner than the other wastes, as there isn't a small dip around the edge of the waste to get filled with discoloured lime scale.

 

I've never seen any mould in there at all, and suspect the regular washing of the surface with water going down the waste keeps it mould free.

Edited October 1, 2017 by JSHarris