What's the best way to permanently stick a ceramic tile to an outside brick wall?
The back of the tile is unglazed, so I'm looking for a solution that will also help protect the tile from the wet British weather.
Options currently in mind are (but open to suggestions):
There is the option to mask around the tile with clear bathroom sealant afterwards, however I'd rather avoid this as it will look unsightly.
Thanks.
If the brick has zero movement year round, buy a high quality exterior rated thin set mortar. And simple follow normal procedure for adhering tile to a wall. A good thin set allows for enough movement that winter, and water, shouldn't be a problem if the substrate is stable.
If you are less confident in the wall's stability then I would suggest a tile membrane and use an exterior rated thin set for both sides of the membrane. Adhere the membrane to the wall, then the tile to the membrane. The membrane will allow for 1/8 inch movement parallel to the membrane without cracking the tile.
Example Tile membrane https://www.lowes.com/pd/Schluter-Systems-54-sq-ft-0-0008-in-Orange-Plastic-Commercial-Residential-Tile-Membrane/4717375
For grout you have the standard choices. Cement based, Epoxy, Urethane, and Resin grout. I've used cement, epoxy, and urethane. Epoxy and urethane grouts are good for slightly volatile environments, but they do cost a lot more than cement. A high quality cement grout will probably meet your needs in most cases.
Also be aware that ceramic tile isn't waterproof. Water will seep through it and drain away. As long as it isn't being sprayed with water at -20 degrees Fahrenheit, it should survive the outdoors just fine.
