How do you fix a cracked ceiling after a water leak?
by
Erik Moller
+3
The ceiling is dry now and brown patches have appeared. Someone said I can't just paint over it.
https://www.doityourself.com/stry/ceiling-water-damage-repair
Yes you can just paint over it if the texture is okay with you. You'll want to start with a "stain killing" primer. Perhaps that is what the advice you received meant. You should not paint just using standard wall or ceiling paint because the stain will bleed through.
Make sure water situation has been addressed first. If it is just diiscolored after drying completely then a nice white primer will assure that the stain doesn’t appear through the paint later. Apply primer with small roller. Let dry thoroughly and then finish with ceiling paint. It may take 2 coats. It is better if you can paint the entire ceiling (room) to assure a Cohesive look. If not your paints may not match.
As for the cracks, use fiberglass seam tape and drywall joint compound if you want them to go away.
https://www.todayshomeowner.com/video/how-to-repair-a-ceiling-crack/
https://www.youtube.com/watch?v=ogP2C7ca6rY
It is possible that the water weakened the structure of the drywall and a large section may have to be removed and replaced. But the standard drywall crack repair is the place to start.
You need to use Kilz on the stain first or it will bleed through with just ordinary primer.