Bathroom painting nightmare !

Hello, I just joined because I desperately need advice on fixing my bathroom paint job. I have a well-insulated, mold-prone New England house built in the 1950's. Paint was peeling off in curls when I moved in, but now every room is fine except the bathroom. I re-painted it about three years ago. There are at least four older layers of paint that will not scrape off the walls except where the paint has cracked down to the plaster. A few years ago, I scraped for weeks, sanded, then spackled all the spots - these spots are like shallow pits down to the plaster, some tiny and some about a foot across. I must not have cured and primed it correctly, because within two years, the spackled areas had cracked and peeled off the walls. Also, everywhere else there are little cracks in the paint like alligator skin. I think I used one coat of water-based Kilz, followed by two coats of Glidden ceiling paint (the ceiling paint is on the walls - that was a suggestion I took). Now, I've scraped everything I possibly could and used an orbit sander. The wall is still awfully uneven because of the old paint. Please give me suggestions! The best course of action I could think of is to scrape and sand, spackle uneven areas and let it cure, then use two coats of oil-based Kilz, then paint with a good latex paint. Is that okay? Should I take a different path and maybe plaster the walls? Should I give up and use wallpaper? Help!!

 

Welcome to the forums!

The age of your house indicates that the original paint was oil base with a high probability of it being lead based While sound lead based paint doesn't need to be removed, it does require a solvent based primer before top coating with latex paint.

I'd scrape off whatever is loose and then coat with either an oil base primer or pigmented shellac, apply joint compound as needed after the primer dries, sand, prime and paint.

 

Spackle is for filling tiny nail holes.
Joint compound is for filling low spots or when taping whole walls.
Is there an exhaust fan?
Oxley moron, well insulated mold prone home.
Balloon framed construction?
How is it insulated?
What type roof venting?
Baffles to allow air flow from the soffits to the roof?

 

In my experience, wallpaper loosens faster than paint does, even when skillfully applied. ........BTW: be SURE you wear the right kind of mask when scraping lead paint because even though you're not sanding still you will loosen particles small enough to inhale. Keep the family out too - lead deposits especially easily in growing and developing body tissues (brain, bone, others). Once there's new sealer or paint on you can relax.

 

While it's always better to play it safe, the odds are the lead based paint isn't peeling. Usually it's the latex paint that was applied over the oil base [without the proper primer] that peels. Anywhere the paint has peeled down to plaster - those areas can pose a lead hazard!! Care must be used to protect yourself and others from inhaling or ingesting lead based chips/dust. The latex paint and/or non lead based oil paint above the lead paint doesn't pose a hazard.

 

It's these few sentences that tell me that the problem is likely to be the kind of paint that was used:

A few years ago, I scraped for weeks, sanded, then spackled all the spots - these spots are like shallow pits down to the plaster, some tiny and some about a foot across. I must not have cured and primed it correctly, because within two years, the spackled areas had cracked and peeled off the walls. Also, everywhere else there are little cracks in the paint like alligator skin.

Latex paint is a "slurry" of different kinds of solids suspended in a mixture of different liquids. The solids in latex primers and paints consist of very finely ground coloured particles (called "coloured pigments"), relatively coarsely ground solid particles (called "extender pigments") and tiny colourless transparent (or transluscent) hard plastic spheres (called the "binder resin").

In North America, over 90 percent of the latex primers and paints are made with binder resins that are made from one of two different kinds of plastic:

1. PVA - or "polyvinyl acetate", which is also the plastic that white wood glue is made of. PVA paint and primer resins have poor moisture resistance, poor UV resistance, poor acid and alkali resistance and something called "poor blocking resistance". "Blocking" is where a paint remains slightly sticky even after it's fully dried. If you've ever rested your head against a painted wall and found that your hair stuck to the wall afterwards, it's because you were resting your head against a wall painted with PVA plastic resins. Alternatively, the wall may have been primed with a PVA primer but never painted, in which case you were still resting your head against a film of solid PVA plastic. PVA resins work well for general purpose primers because the top coat of paint will prevent the primer from being exposed to acids, alkalis, UV light from the Sun, humidity in the air, and all those other things that PVA plastic resins have poor resistance to. About the only advantage that PVA resins have when it comes to making a paint or primer is their relatively low cost. Within the business, primer and paint resins made of PVA plastic are referred to as "vinyl acrylic" resins.

2. PMMA - or "polymethyl methacrylate", which is also the plastic that Plexiglas is made of. PMMA resins are used to make top quality interior latex paints, all exterior latex paints and primers for fresh concrete where high alkali resistance is necessary. PMMA resins are also very much more resistant to moisture than PVA resins, and any paint made specifically for bathrooms (like Zinsser's PermaWhite Bathroom Paint, sold at Home Depot) will be made with a PMMA resin that's expecially highly resistant to moisture and high humidity. Within the business, primers and paints that use PMMA plastic binder resins are referred to as "100% Acrylic". There is no such thing as 50% acrylic primer or paint resins or 75% acrylic primer or paint resins; there is only "Vinyl Acrylic", "100% Acrylic" and "Styrenated Acrylic" primer and paint resins. Some paint companies use that terminology to fool paint consumers because they slap that term "100% Acrylic" prominantly on their labels. People should understand that the term "100% Acrylic" simply means that the resins inside the can are made of the same plastic as Plexiglas, but there are literally thousands of different kinds of 100% Acrylic resins used to make everything from floor "waxes" to grout and masonry sealers to water based "varnishes" to paints and primers and even nail polishes for the ladies. So, "100% Acrylic" on a can of paint means about as much as the wording "100% Cow" on a package of meat. It tells you that what you're buying came from a cow, but it doesn't tell you if you're buying prime rib or dog food.

Probably the most common misdiagnosis when it comes to paint is why the paint peels high up on bathroom walls and on bathroom ceilings. (Generally, high up on the walls where the walls meet the ceilings and with the worst cracking and peeling on the ceiling directly above the shower.) Most people simply attribute this to poor paint preparation, or improper priming or improper something else (like "curing" which the OP suggested was the cause in his post.) In fact, most of the time the real cause of paint peeling in bathrooms is the fact that a paint with poor moisture resistance was used. And, generally, the fix is as easy as painting over what you have with several coats of a paint that's well suited to bathrooms, like Zinsser's PermaWhite Bathroom paint, tinted (or not) to the colour of your choice.

In this case, the OP used a ceiling paint. Nestor clambers up onto the rooftop of his small and humble hut and calls out in a loud voice for all to hear: "Ceiling paints are nothing more than wall paints made to a lower standard than wall paints. Ceilings don't have to stand up to hard scrubbing to remove stubborn marks, like wall paints do. Ceiling paints are basically what you get when the paint company tries to save it's customers a few dollars. They provide a paint of lesser quality for use on ceilings where you don't need as high a quality paint as you do on your walls. Whomever is formulating a ceiling paint is going to use a plastic resin that doesn't have very good moisture resistance because ceilings generally don't get wet."

What happened in the OP's case is that he prepped the bathroom walls and ceilings well, and then painted them with a ceiling paint. That cheap latex paint didn't have good moisture resistance, and the moisture and humidity in the bathroom caused it to crack up (called "alligatoring") and peel in places. Had the OP used a paint formulated specifically for bathrooms, that problem never would have happened.

Luckily, the fix here is just to re-prep the walls for painting and use a paint specifically meant for bathrooms as the top coat. Zinsser's makes their PermaWhite Bathroom Paint, but Sherwin Williams also makes a paint specifically for bathrooms called simply "Bath Paint". Either one of those two paints will solve the problem with the paint cracking and peeling in the bathroom.

The OP can use an oil based primer if he wants to, but my experience in my 21 bathrooms is that all that's really needed is to smooth the walls (by filling in any paint cracking with joint compound and sanding smooth), priming, and then using a paint meant for bathrooms as the top coat. The top coat of bathroom paint will be impermeable enough to moisture to prevent the lesser quality paint under it from continuing to crack and peel.