Should I strip the flaking ceiling paint before applying Kilz Mold and Mildew primer, or just remove what I can and paint over it?
Asked by Alolika Dsouza 
3 months ago
Last Updated: August 16, 2024
Hey, so it looks like the ceiling paint is peeling off in sheets. Do you think I should strip it all off or just take off what I can easily? I’m planning on painting over it with Kilz Mold and Mildew.
It appears that section has been fixed previously. Remove as many layers as possible until you reach a stable surface, whether it’s drywall or plaster. Apply an oil-based primer before patching, priming, and painting.
Is this located in a bathroom? If it is, you might consider making a repair, but keep in mind that without proper ventilation, the issue could recur. Are you aware of the material beneath the paint? Is it drywall or plaster?
It could be related to excess moisture, but it seems like the issue might be due to painting over the original oil-based paint with latex. That’s not recommended. If that’s the case, you’ll need to remove as much of the paint as possible and then follow Eric’s advice by using an oil-based primer before applying the paint of your choice. Latex paint can adhere to an oil-based primer, but not directly to oil-based paint.
Remove and repair the area properly, otherwise the issue will keep coming back if it’s simply painted over.
To address the moisture problem, ensure that the bath fan is vented outside through the roof or wall and not into the attic. Insulate any exposed tubing in the attic to prevent condensation buildup in the pipe.
Most fans work best with a straight run of about 1ft before any bends or turns for optimal performance.
Keep the total length under 25ft, considering each elbow as 5ft.
In addition to all the fantastic tips already shared… I definitely suggest getting a timer switch for your fan. It’s really helpful to be able to set your fan to continue running for 5 to 10 minutes after a shower to help eliminate moisture both in the bathroom and the ductwork. This is especially important in smaller bathrooms. Sometimes people take a quick shower, turn off the light and fan when they leave, but there’s still a lot of moisture left behind… You can find both digital and analog timer switches that are very easy to set up. Spending $25-$30 on the switch is worth it to manage humidity.
If the ceiling wasn’t primed before painting, it’s likely that the same issue will eventually affect the entire ceiling over time.
I’ve experienced this before – the previous owners used the wrong type of paint. When I remodeled the entire bathroom, I made sure to use primer and specific bathroom paint. It has held up well for more than a decade.
Let’s start fresh by scraping it, applying a skim coat, and then painting over it.