Tiling shower onto new plaster

[markspark101]

Dear all,

I hope you can help. Here's the deal... I have a newly plastered shower enclosure. My plasterer finished of with a water based stabilising solution (not PVA) to reduce the chalky/dusty/porous finish of the plaster. This was absorbed into the plaster; there's nothing left n the surface. I am fitting 11cm Malborogh tiles on the shower walls. My question is this. How should I prepare the walls for tiling - if at all? I do not have enough width for any sort of backing board. The plaster is solid and onto brick/blockwork. To be safe I fancy using a paint-on tanking product; what is the best to use?

Elsewhere I have to seal around a basin onto the plaster. Will silicon adhere to the plaster to form a watertight seal or will I have to paint the surface first?

Oh I nearly forgot... I have read loads of conflicting advice regarding the type of adhesive and groat to use in the shower. I have used a ready mixed adhesive (Sealocrete Sealogrip) and a bagged groat product (Evo-stick White for Life) for elsewhere in the bathroom but I am concerned that these 'waterproof' products will not be up to the job in the shower (I used on a tiled outside table and the tiles came off - adhesive went to mush when it got wet!!). Please be explicit. What product and where can I buy it... Do I use a notched trowel or should I use a solid bed?

Grateful for any advice you can offer.

Mark.

 

[flameport]

What has been done so far all sounds like a catalogue of mistakes.

It is not usual to plaster walls in a shower enclosure, there is no point and in many cases it is unsuitable for tiling over.
New plaster shouldn't be dusty or chalky. If it is, there's something wrong with it.

Silicone will adhere to plaster and most other materials, however while the silicone will be waterproof, the bare plaster certainly won't be.
Silicone will adhere to emulsion paint, but that is hardly a suitable surface to have directly behind a basin.
Surely you will be having tiles behind the basin? If not, you can expect to be repainting it several times a year.

11cm tiles are very small for a shower, and the result will be huge amounts of grout lines where water can penetrate.

Adhesive type depends on where it is being used, the surface it is being applied to and the size & type of tiles being fixed.

I have never used any Sealocrete products, but the datasheet for Sealogrip ( http://www.sealocrete.com/docs/datasheet/Sealogrip Acrylic.pdf ) clearly states it is for interior use only and not suitable for permanently damp conditions. Not surprising that it failed when used on an outside table.

Most of the answers to your questions can be found here: //www.diynot.com/forums/viewtopic.php?t=77709 or by searching this forum for the many other posts on tiling shower enclosures and bathrooms.

 

[markspark101]

Thanks Flameport for your comments. I don't believe that there have been a catalogue of mistakes; it's just that I am where I am. When taking off the old tiles in the shower area, the adhesive pulled off much of the plaster skim hence I had to have it re-skimmed so that I could re-tile. No choice, not enough room for my preference which would have been to add some sort of waterproof backing board. This why I was asking about a paint on membrane that I could add - unfortunately you didn't answer that part of my question! My question re silicon adhesion to plaster is still valid but I did not give the full explanation. I still need to do this hence my question. Regarding the 11cm tiles... I want the grout lines to be aligned with the other tiles elsewhere in the room so I am where I am. Surely mosaic tiling has same problem as you suggest so what product is used there to ensure seal? Incidentally the previous tiling was just dot and dabbed onto the plaster and then grouted. No leaks. This was probably a fluke. Looking for best advice. The Sealocrete adhesive will definitely not be used; the outdoor table was an experiment to see what happened and hence the follow-on question re best/most suitable product.

Still not sure what to do! Grateful for any positive advice rather than comments regarding what is wrong. This has been a long project and I am on the last stage. See my album for pictures. As I said, I am where I am and I need your support.

Thanks,

Mark.