Paint Peeling Off Drywall
Louise Sargent, who lives in Gilford, NH just a few miles from my house, has a problem with peeling paint from her drywall.
"Dear Tim, I read your video about priming drywall before painting for even absorption of paint.
Is curing drywall the same as using a primer? A few flakes of paint are loosening up as the years pass on the walls. A reason stated was that the drywall was not cured.
I think it's from humidity. What do you think?"
Louise sent a photo, but it was out of focus. Imagine a 3-inch diameter spot of peeled paint from drywall where the paint around the edges is curled up.
Here's my answer to Louise:
Whoever told you cured drywall, or the lack thereof, is wrong. The joint compound used to finish drywall is not like Portland cement or concrete that actually is a curing or hydration chemical reaction. Drywall joint compound is a very simple basic glue that has dust or filler in it. Think about the white glue kids use in school. That's very similar chemistry.
The glue in the joint compound just dries in a few hours or maybe a day if humidity is high when the compound is applied. Once dry, it's done.
I feel your peeling paint could be one or two things.
First, it could be the drywall was not dust-free when it was painted. Often painters don't wipe off the dust from the drywall sanding process.
Keep in mind that paint is just colored glue and dust can get in the way of the glue binding with the joint compound. If paint peels from drywall and you can get dust from the back of the paint peel or the surface of the drywall, you pretty much know this was the issue.
The second reason is the paint may have been inferior. Cheap paint has poor-quality ingredients like a cheap glue. Over time gravity defeats the poor bond of the crappy glue in the paint.
Just try to scrape as much paint off the walls as possible, skim coat the peeled areas, sand, wipe the dust and repaint with a top-quality primer / sealer and then paint!