Mist coat mistake

The Necessity of Mist Coating for Newly Plastered Walls: While the allure of a freshly completed plaster job may tempt immediate painting, skipping a crucial step - the mist coat - can compromise the entire aesthetic and longevity of your paintwork. Reasons for Mist Coating: Enhanced Porosity Control: New plaster exhibits high porosity, readily absorbing paint, leading to uneven coverage and wasted product. A mist coat, typically thinned paint (50% water), acts as a primer, regulating paint absorption and ensuring a smooth, consistent finish. Optimized Adhesion: Beyond regulating absorption, the mist coat promotes optimal paint adhesion to the underlying plaster. This minimizes the risk of future peeling and flaking, safeguarding both the aesthetics and longevity of your paintwork. Strengthened Plaster Matrix: The thinned paint solution penetrates deeper, consolidating the plaster matrix, enhancing its resilience against moisture and wear. This provides a more robust foundation for subsequent paint layers. Surface Smoothing: Minor imperfections in the plaster are often imperceptible but can affect the final paint finish. The mist coat acts as a light filler, smoothing the surface and creating a canvas primed for flawless paint application. In essence, the mist coat serves as a vital intermediary step, ensuring not only aesthetic appeal but also the durability and longevity of your paintwork. Neglecting it may lead to costly and time-consuming rectification in the future.

Tha plastering was not good

All new plaster needs a mist coat first

Hi is this an external wall? Sounds like efflorescence

All newly skimmed plaster needs a mist coat to act as a primer and stop peeling in the future.

yes if walls was not mist coated this can happend but can be many other reasons. what can do is to remove all loose paint, repair and sand and then apply Zinsser peel stop. When that is dry paint the walls again. If is just mist coat issue this will stop it

Sounds like your painter left you with a mess. If you continue painting over the flakey paint you will continue having the same problem. So, basically you will have to start from scratch. Remove all the flakey paint. I suggest carefully sanding the walls with a fine sandpaper but be careful to not damage the plasterwork or to make it uneven (meaning don't press hard on the wall when sanding it down). Then, using a soft brush or dry cloth, thoroughly wipe the walls down to ensure that the surface is clean of any dust/ paint powder. Then apply Peel Stop (Zinsser), which is a clear, flexible bridging sealer for surfaces where peeling, flaking, dusting or chalking is a problem. When the Peel Stop has dried completely you can repaint the walls.