Mastic wall hung toilet

[Russdl]

The instructions for my wall hung toilet are brief. There is no mention of applying mastic between the bowl and the wall.  I’m sure I should, shouldn’t I?

 

Top and sides? Guidance appreciated. 

 

 

[PeterW]

What frame ..?

 

And did it come with a gasket..?

 

If not, decent bed of CT1 and then use a replaceable silicone all round the rest of the pan when that has gone off. If there is no gap under the pan then use a 2mm packer wrapped in cling film to make a gap at the bottom of the pan /CT1 so any leaks in the future are visible. 

[Russdl]

The frame is a Geberit Duofix. No gasket. 
 

The toilet bowl is Lusso, vague instructions. 
 

 

[joe90]

Wot @PeterW said ?

[PeterW]

15 minutes ago, Russdl said:

The frame is a Geberit Duofix. No gasket. 
 

The toilet bowl is Lusso, vague instructions. 
 

 

got a photo of the bottom / back of the pan ..?

[Russdl]

@PeterW Here’s one of the back and underside. 
 

[Mr Punter]

I would not bed on CT1 as if there is any future issue with the pan or plumbing behind you will wreck the tile.  Just silicone will be fine.  The frame does the job of supporting the pan, not the mastic.

[Onoff]

If it helps I think it's this one:

 

[Onoff]

48 minutes ago, PeterW said:

What frame ..?

 

And did it come with a gasket..?

 

If not, decent bed of CT1 and then use a replaceable silicone all round the rest of the pan when that has gone off. If there is no gap under the pan then use a 2mm packer wrapped in cling film to make a gap at the bottom of the pan /CT1 so any leaks in the future are visible. 

 

Exactly what I did save my bottom is wide open thus didn't need the pack trick.

[Russdl]

@Onoff yep, that’s the one. 

[Onoff]

@pocster is having similar wall hung pan issues at the moment but his frame and pan are both Geberit. 

 

Hopefully your fixing inserts fit the pan fine?

 

I'd CT1 it assuming your wastes behind are all good and leak free then the Geberit frame is pretty much bullet proof and accessible through the flush plate for maintenance. If those wastes fail then it's tiles off and cut through the wall board time anyway!

 

I was particularly careful testing before boarding over, not least as I had a two different makes, "wrong way round" F to M joint where the grey meets the brown, solvent joint (done with pvc gap filling cement then CT1'd over):

 

 

I even mocked up a pan to test the flush etc:

 

 

[Russdl]

@Onoff I’m pleased to say that the pan attaches to the (buried behind tiles) frame without issue. It’s just a case of finishing it off, where to mastic/CT1 and where not to. 

[PeterW]

Decent bead of CT1 all round about 20mm in from the edge and nip the bolts up. Level it across the back then tighten, wipe any excess CT1 off the pan or tiles and the leave for 24 hours. Then go back over with a decent LMN silicone of your choice. 

[Onoff]

Baby wipes to get the excess CT1 off the tiles.

 

(Thanks to @Nickfromwales for that top tip).

Edited January 30, 2021 by Onoff

[wozza]

I used BT1 on mine.

[Onoff]

9 minutes ago, wozza said:

I used BT1 on mine.

 

It's good isn't it? Different consistency to CT1. Did you use it as the final finish?

[wozza]

Just now, Onoff said:

 

It's good isn't it? Different consistency to CT1. Did you use it as the final finish?

 

Yeah its a bit nicer to use and I did use it as the final finish. - Its a bit pricey though.

[PeterW]

24 minutes ago, Onoff said:

Baby wipes to get the excess CT1 off the tiles.

 

(Thanks to @Nickfromwales for that top tip).

 Cheaper the better !! Aldi own brand are good !

[Russdl]

Thanks all for your inputs, much appreciated as always. ?

 

Just one point as @Mr Punter highlighted. If I use CT1 then a couple of days later drop something heavy on the pan and break it (could happen, has happened in the past!) would I ever get the broken pan off the wall?

Edited January 30, 2021 by Russdl

[PeterW]

2 hours ago, Russdl said:

Thanks all for your inputs, much appreciated as always. ?

 

Just one point as @Mr Punter highlighted. If I use CT1 then a couple of days later drop something heavy on the pan and break it (could happen, has happened in the past!) would I ever get the broken pan off the wall?

Yes - sharp thin blade will take it off as will a guitar string as a cutter. 

[Russdl]

15 minutes ago, PeterW said:

as will a guitar string as a cutter. 

I knew my sons hobby of breaking guitar strings would come in handy one day!

[dpmiller]

yep, it's used for removing bonded car windscreens too.

[Nickfromwales]

I always CT1 here as the casting of porcelain is often imperfect, as is often the tile ( especially where the pan traverses a grout line and there is a distinct wobble ). Cutting through CT1 in the event of a doomsday issue is a few minutes work. CT1 Multisolve can be used to break down and remove residual product, and clean up before re-installing. Hearing a 'dry' pan grating against a tile whilst you tighten, and then do the first test arse-fit, is bloody daunting to say the least.

And the gasket should be banned from existence  !!!!!! Do not fit, it's like a bloody slip membrane and stands the pan off an extra few mm's which means more silicone on the upper rear edge of the pan.?

[Mr Punter]

We have just used silicone.  They fitted about 40 of these on a project a couple of years ago.  No problems at all.

[Nickfromwales]

13 hours ago, Mr Punter said:

We have just used silicone.  They fitted about 40 of these on a project a couple of years ago.  No problems at all.

Silicone will do the same job if it's a very thin gap but it's not a bonding agent at all, just a sealant, so if it fails you can have expected nothing more from it. Silicone is a finish product, and has very little integrity vs a non-silicone product like CT1. Also, it attracts mould aka black death, so I very much like using it to create a top 'cosmetic layer' which can be easily removed and refreshed when the bathroom gets a freshen up / new lick of paint. 5 years is about right for silicone, after that it seems to start to show its age with any kind of regular manual / direct cleaning.