I'm planning on covering part of the exterior façade with tile.
Unfortunately, I have some concerns about tile adhesion since the plaster on top is synthetic resin based plaster (plaster grain size 1.5 mm).
According to my information obtained after talking to a tiler, no adhesive will hold properly on this plaster.
The alternatives suggested to me so far have been as follows:
1) The plaster and insulation should go down where the tiles are glued. Then pre-treat with a two-part adhesive and work with a quick-setting tile adhesive.
2) Screw the wedges to the wall and glue the tiles on top.
In total, a cohesive tile pattern takes up about 30 square meters and goes either lengthwise (about 2 x 17 m) or heightwise (7 x 5 m).
I would prefer that the tiles can be glued directly to the façade or that they appear to be glued directly to the façade.
I assume that alternative 1) (see above) would not be possible.
Here is the façade description I received from the architect:
ETICS for a facade consisting of a mineral wool insulation board, lambda 0.034 E/mK, adhesive mortar and reinforced organic base coat, nominal layer thickness 5 mm, intermediate layer (primer) and top layer of synthetic resin plaster, 1.5 mm plaster grain size, painted through scratch.
ETICS insulation board: 20.0 cm.
Material: STO THERM MINERAL
Dowel, clean, reinforce, glue with Ardex X90 and epoxy. Then it should work :)