Repairing PLASTIC shower wall tile

[iwrk4dedpr]

Well woke up this am to this. Asking for how to repair.
1. Tile is plastic. Yes PLASTIC.
2. Wall is plaster. I've had the scrapper out and the "glue" or what ever was there holding the tile came off easily. As I scrapped it felt like the plaster was scraping up as well.

I've got other tiles that I'll address as well but I need information on how to proceed.

How or what do I need to address the plaster walls? I know scrape off all the old mortar/adhesive as much as possible.
What else? Do I need a sealer or some sort of coating? If you have a product in mind please if you can find a link HomeDepot/Lowes/Amazon that will be useful.

Seeing how todays showers are typically ceramic tile. Is the mortar like this Amazon Product Link : SimpleSet Pre-Mixed Thin-Set Mortar 1 QT appropriate?
Also assuming that I'd need Amazon Product Link : Notched Trowel

Is spreading the "mortar/adhesive" from edge to edge sufficient to ensure water does not infiltrate?

Does anybody know of a good YouTube or other source of a repair video.







This tile is also popping ... but it shows the edges of the tiles and how or lack thereof of the "grout"

 

[iwrk4dedpr]

Got all the remaining loose tiles off. Cleaned and reattached to the wall.

 

[bud16415]

Sorry no one came along with any advice for you on setting your tiles. What did you use to attach them?

Without some kind of sealer in the joints I think you will have an ongoing problem with water and heat/steam causing them to loosen up again.