Hi, I have a very small area (1m.sq) on an exterior doorway entrance wall to tile. I would prefer not to use ready mix adhesive but looking for a good alternative solution if any only due to buying a very large bag of adhesive powder which will go to waste. I would appreciate any thoughts on ready mix and brands if anyone has experience with long term longevity of the tiles staying put. The area although a small external wall is sheltered but not the cold.