I recently decided to repaint my bathroom ceiling with a moisture-resistant paint, hoping to fix some old water stains. I carefully prepped the surface, used a primer, and applied two coats over a couple of days. Everything looked fine until after a particularly steamy weekend of long showers - the paint started bubbling in random spots. I double-checked that the bathroom fan is working and even left the window open to air it out, but the bubbles keep appearing. Has anyone dealt with paint bubbling caused by humidity, even with moisture-resistant paint? Should I consider a different type of paint or maybe a different prep method? Also, is there a way to fix the bubbles without repainting the entire ceiling?

On 01/31/2026 at 3:55 PM, SunnyVibes said:

I recently decided to repaint my bathroom ceiling with a moisture-resistant paint, hoping to fix some old water stains. I carefully prepped the surface, used a primer, and applied two coats over a couple of days. Everything looked fine until after a particularly steamy weekend of long showers - the paint started bubbling in random spots. I double-checked that the bathroom fan is working and even left the window open to air it out, but the bubbles keep appearing. Has anyone dealt with paint bubbling caused by humidity, even with moisture-resistant paint? Should I consider a different type of paint or maybe a different prep method? Also, is there a way to fix the bubbles without repainting the entire ceiling?

Sounds super frustrating, @SunnyVibes! Even moisture-resistant paints can bubble if there's trapped moisture underneath or if the surface wasn’t 100% dry before painting. Sometimes old water stains mean the drywall or plaster is still holding moisture, which can cause bubbling no matter what paint you use.

One trick that helped me was to gently scrape off the bubbles, let the area dry completely (sometimes using a dehumidifier or heat lamp), then spot-prime with a stain-blocking, moisture-sealing primer before repainting. Also, some folks swear by specialized bathroom ceiling paints designed specifically for high humidity, which might be worth trying if you want to avoid a full redo.

Have you checked if there’s any lingering leak or condensation issue behind the ceiling? That could be the root cause. Otherwise, airing out the room more aggressively after showers might help, but it sounds like you’re already on top of that.

That sounds super frustrating, especially after all the prep work you did! Sometimes moisture-resistant paint isn’t enough if there’s still trapped moisture beneath the surface from previous water damage. If the old stains were from leaks or persistent dampness, that underlying moisture can cause bubbling no matter what paint you use.

Before repainting, I’d suggest making sure the ceiling is completely dry - maybe even use a moisture meter if you have one. Also, some folks swear by using a shellac-based primer over stained or damp areas before applying moisture-resistant paint. It creates a better seal and can help prevent bubbles. For the bubbles you already have, you might need to scrape them off, let the area dry fully, then spot-prime and repaint just those spots instead of the whole ceiling.

It’s great you’ve got the fan running and the window open - that’s key to preventing future issues. Hopefully, with a bit of extra drying time and sealing, you