Fresh peeling paint

Obviously you forgot to add sun factor to the paint!!!!

 

It is known as a mist coat. I normally thin it out 50/50 paint/water when putting directly on plaster.
Plaster obsorbs water quickly as it is a very pourus surface, which causes paint to dry out too quickly, and crack or peel.
I personally prefer brushes, but a roller with short/thin pile is better suited.

 

Could be wall was greasy? Did you clean it down? Not something do but sometimes you will see if it needs de greasing. No damp there?

 

I recently painted a wall but it was freshly plastered. I thinned down the matt emulsion. It was very watery going on! I gave it 2 coats like that and then couple of top coats. But you are saying it is not the freshly plastered section that is peeling?

 

Possibly paint not adhering to the wall properly. As kools said, it is possible the wall could have been greasy. Also possibly wall was not completely dry as bathroom environment etc.

 

You would need to wash it down if still greasy.

http://www.screwfix.com/p/no-nonsense-concentrated-liquid-sugar-soap-500ml/61880

 

Was it going over previous paint? Not going over a tile backer, such as hardibacker?

Where is DA when you need him
Kools? We could do with him here.

 

Only in that area?

 

And only one section of that wall is reacting badly?

Could be the paint you are using! Bad batch?

 

If I'm reading this correctly it appears you have an adhesion problem between the two types of paint, was first coat fully dry before applying the bathroom paint?

 

Shouldn't have to put anything on. Wash it down with sugar soap. I don't like that fancy paint to be honest.