Revisions log for Answer #1186
This is the answer to the question What to finish the porch with?
Revision 1
There is a chance of "cracking" in this form. You definitely shouldn't do the plinth that way. The fundamental difference between the facade and the plinth is the effect of water. According to this, almost all materials except the primer are different.
The scheme of finishing:
Substrate preparation – usually primer = substrate must be firm, level, dry with no biological damage.
Leveling layer if necessary.
Base layer (glue + mesh) – desirable, but sometimes not necessary (depends on the specific task) – this is the base for the finish layer.
The final layer – protection + decor
On the plinth will probably need waterproofing.Between layers – may need a primer, depending on the materials used.
You mentioned only the visual component of the finish coat. In your case. The columns can finish any material (even a stone, at least under the marble) plaster finish one of the options. Basement finishes only (!) with materials that are not afraid of contact with water!