Really need advice please. I repainted my bedroom just coming to a year ago. I took off all old paint etc which took hours, filled cracks etc with pollyfilla and sanded down to smooth then gave walls 2 mist coats i then emulsioned which looked great. Now the paint is peeling, cracking and some large stains are appearing. They dont smell damp. It s only happening on an external wall. What can i do? Do i have to take off all emulsion and start again? Should i have used the Zinsser paint Please advise. Any help will be greatly appreciated. Thanks