The Conditions
If you are going to paint walls outdoors, you should do it under suitable environmental conditions, do not paint if it is raining or you think you can do it and paint facing the day.
Preparation
Eliminate possible remains of badly adhered paint, lime, saltpeter or other possible contaminants, in case of walls in bad condition, it is advisable to sandblast them until a well consolidated surface is obtained.
What do I paint with?
There are different types of exterior coatings; stone, elastic, silicate, siliconized coatings, etc.
Look for quality paints with a high percentage of binder, low water absorption and good water vapor breathability.
Color
Always ask for coatings made with light stable pigments, otherwise the painted wall will discolor in a short period of time.
Your Safety
Use adequate means of protection and do not allow children to go near the paint. If you use scaffolding or lifting equipment, ask for it to be approved and follow the safety instructions indicated by the manufacturer.
Everyone's Security
Dispose of waste in a responsible manner. Follow the instructions described in the safety data sheet of the product.