Tiling the underside of boxing over a shower bath

[Rusti]

Hi,
I need to tile the underside and side of some boxing on the ceiling but whereas on the walls I've been able to fix batons and set the tile positions with spacers and wedges, there is no support on the boxing to set them against. I am thinking I could screw wood in place on the bottom of the box to support the side ones, but I can't think of a good way to support the bottom ones properly. Has anyone any experience of this sort of thing?
Thanks

 

[faithhealer]

I just use a rapid set adhesive, mixed just wet enough for the suction to hold them in place until set. You can buy ahesives that set in 5 mins if you wish but a a bit pricey for a few tiles.
ps welcome to the forum

 

[Perry]

depends what tiles,size and what the boxing is made of and welcome to the tile forums ete

 

[Rusti]

Thanks guys. I might try and set up a couple of supports with a bit of old skirting board or similar and wedge it in place. The boxing is made of mdf with plaster over it, then paint. I have scratched the surface with a stanley knife to get a key and then used a primer.

By the way topps recommend using a waterproof sheet under the tiles around baths & showers but when I have knocked old tiles off for a restart i have never come across an old one of these sheets and the tiles have still been stuck fast. Are these sheets necessary or just a marketing ploy? They are so expensive.

And thanks for the warm welcome!

Cheers

 

[faithhealer]

What topps are trying to sell you is a tanking membrane which we would recommend for a shower wall but not necessary around a bath. You can also buy, 'paint on' tanking systems which are easier for the diyer. Search 'tanking', on this forum. No marketing ploy, they do the job, they are loads of stories on here about ruined bathrooms because they didn't tank
Re your boxing, plaster on mdf doesn't sound a good combination, think I would be screwing a backerboard such as Hardiebacker on no more ply to it first

 

[Perry]

where is the boxing in the shower ? mdf with plaster over it, then paint. I have scratched the surface with a Stanley knife to get a key and then used a primer. i hope its not mdf but plaster board if it is timber screw a piece of plasterboard to it and how big are the tile cuts that are being stuck to it what adhesive are you using because the adhesive i would use would hold a 600 x 600 porcelain up with no support

 

[Rusti]

My mistake, it is plasterboard. I've screwed a board underneath and tiled the side today, will attempt the bottom tomorrow. I think I will mix my adhesive a bit stiffer and let it go off slightly before sticking it. I think my adhesive has been a bit runny so far as the stiffer mix I used today seemed to work well and the tiles sat in it ok without sliding around too much. I'm using Topps rapid-set trade adhesive.
The tiles are 25 by 50cm.

As for the tanking issue, it is a shower bath. I haven't actually tanked it so fingers crossed it will be ok.

 

[Perry]

sorry never used that adhesive but most rapid sets don't have any body so will tend to slip you can always attach masking tape just in case it slips as for the tanking doesn't sound like it going to get drenched around the boxing