Split Faced Stone Mosaic "Tiles".

[Thepipdoc]

I'm considering cladding an external wall using Split Faced Stone Mosaic "Tiles".
(I have used this type of tile on a internal living room wall and in this particular instance I got them from Porcelanosa.)
https://www.houzz.com/s/u=aHR0cDovL...saXQtRmFjZS1tb2Rlcm4tZmxvb3ItdGlsZXM/m=8/t=77

The Porcelanosa split faced tiles were excellent and I would have used them outside but the individual pieces are not as big as I would have liked.
I would prefer them generally larger because its quite a big wall I'm covering and I think small tiles wouldn't look quite right.
My questions are - does anyone know where I can get largish split faced stone tiles from, also,will I be OK sticking this type of tile onto an external wall? I'm specifically thinking of the problems that might occur with water/moisture getting trapped behind them. I would intend capping them with lead but because this type of tile has no grout there would be nothing to stop driving rain penetrating them
Any help much appreciated.

 

[White Room]

What type of external wall, one connected to the house or a stand alone one...

 

[Thepipdoc]

What type of external wall, one connected to the house or a stand alone one...

The external wall is a gable end of the house. It has been rendered, then terylened and then painted with masonry paint.

 

[White Room]

The paint and roughness of the tyrolean would not allow a good fixing, also the moisture being trapped behind the tiles and not being allowed to escape would be a concern...