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LisaDarln 10-21-2008 09:27 AM

Bathroom Pre-Painting Troubles
 
I would love to be able to hire a professional painter, but we just cannot afford such a luxury. Since I am a stay at home mom/wife, with all the time in the world, I saw no reason why I couldnít just paint the bathroom myself. Unfortunately I have run into several problems and seek some advice. I feel it necessary to explain everything from the beginning and in detail in order to gain that help, so I apologize in advance for the length of this post.

The bathroom walls are flaking. I use the term flaking because peeling does not seem accurate. Peeling is something I equate with length, such as when you peel a cucumber. This problem is more akin to dandruff. Remember the old Head and Shoulders commercials with the white flakes visible on the shoulders of people wearing dark colored shirts? There are patchy flakes of paint that fall off the wall and onto the floor, so basically our bathroom has wall dandruff. A closer look reveals that nearly the entire wall is cracked, like you might imagine glass to appear before it actually falls apart. Then, there are VERY FEW areas that seem to be smooth and proper.

My initial inquires with how to start this job, I was told that the problem occurs due to the moisture in the bathroom and the paint would have to come off with sandpaper, the wall re-prepped, and repainted. I get some sandpaper, but nothing appeared to be coming off at all in the cracked areas. I make further inquires and told to use a sander. I do this, but the blue paint layer basically melts and smears revealing a pink paint layer beneath, and essentially ruins the sandpaper. I make further inquires and Iím told to just chip away at it with a putty knife. No problem, I have an unusual patience and all this time, right? Well, I have learned that the painters of the pink layer failed to prep the wall at all prior to painting. They painted right on top of the wallboard, drywall, or whatever itís called, and I basically, the wall sections without joint compound are also removing the white paper covering, which I think is called gypsum. Anyway, I research this problem and find out that this problem typically occurs with wallpaper removal and can be fixed by basically rebuilding the wall with Guardz and a couple layers of joint compound. Iím more willing to do that job, rather than tear down a wall and hang another one. As I said before, Iím just a mom and wife, not a builder, and I have the time and patience. This leads me to my question. Is it still necessary to me to rid the walls of the previous paint layers?

Since I basically have to rebuild or recreate a smooth wall surface anyway with the Guardz sealer and joint compound, would this not also cure or glue the underlying paint layers? It theoretically sounds good, but I would hate to be wrong and have the wall dandruff return.

Thanks to all who respond.

DangerMouse 10-21-2008 10:13 AM

1 Attachment(s)
sure sounds like a lot of work trying to get the wall even again. have you considered other approaches? perhaps some nice Wainscoting and new water-resistant wallpaper? (see pic) to me it seems paint and a wet bathroom doesn't make sense, as it's where i see more peeling paint than anywhere else in most homes i've been/worked in! there are also plastic full wall sheets you can attach and waterPROOF the bath if you wish. plenty of great tile guys here if you wish to go that route too! :thumbsup: Po)

DM

Matthewt1970 10-21-2008 10:18 AM

Hard to say without seeing it firsthand, but with the severity of the problems you have listed, I think you may be better off ripping out the drywall and starting over. You have a top layer that didn't stick well, which even if you got all the flaking spots now, there are probably plenty more spots about ready to let go as well and adding more paint ontop of them won't help much. They could very well start to bubble up and flake the second you add another coat of paint or primer. You have cracking in the bottom layer of paint as well which will be even more of a problem.

At this point, I would pay a pro to come by and just give you some advice on what to do next. I could tell you to scrape all the walls and then prime, smooth with joint compound, prime again and paint only to have more layers pop off or the bottom layer crack more and ruin your job.

bjbatlanta 10-22-2008 09:21 AM

I have repaired a lot of walls in as bad or worse shape than you are describing, so I don't think you're to the point of total demolition of the walls. I do recommend seeking professional advice. You can likely go the route of priming with oil base, glaze with joint compound (2 or more coats), prime again, and paint. It might be worth paying a pro to do the mud work at least. As Mathew said, it's hard to say for sure, sight unseen.........

sirwired 10-22-2008 03:54 PM

I would lightly go over with a paint scraper the entire wall to knock down the really loose stuff. Then, wash down the walls with TSP and rinse. This will remove things like hairspray residue. Your next step should be a product like Zinsser Gardz, which will "lock down" the damaged drywall, and if you are really lucky, the lousy paint. Next, skim-coat the wall with slightly thinned pre-mix joint compound. Lastly, prime and topcoat with two coats of quality bathroom paint.

Also, if the bathroom does not have a fan installed, put one in, if at all possible.

SirWired

bjbatlanta 10-22-2008 06:17 PM

SirWired has a very good point about the fan.........could be a big part of the problem.

Nestor_Kelebay 10-22-2008 09:28 PM

Lisa:

If you've torn off any of the white surface paper from the drywall, you can repair it as follows:

Use self adhesive fiberglass mesh drywall joint tape, and apply two coats of that tape. The first coat should consists of strips of tape going across the area where the drywall paper is missing, and the second coat should be laid down perpendicular to the first. Each coat should consists of fiberglass mesh strips that go right over the area where the paper is missing and a good few inches onto either side of that area. Mix up some white wood glue with enough water to make it into a paintable consistancy and paint that dilute glue onto the fiberglass mesh strips after applying each coat of fiberglass mesh strips. As the dilute glue dries, it will bond the strips of fiberglass tape to the gypsum core and surrounding drywall paper, thereby restoring the strength of the drywall in that area. (It's really the paper on each side of drywall that gives it strength and rigidity.)
Then, after the glue dries, just apply a thin coat of joint compound over that, and sand smooth being careful not to tear up the fiberglass mesh with your sandpaper.

And, always, always, always, when applying joint compound or sanding it down, do so with a bright light shining across the surface you're working on. The illuminaton from the side will exagerate the roughness of your work, giving you a much better idea of where to add joint compound and where to sand it down to get a smoother surface. When it looks acceptable under such critical lighting, it'll look perfect under normal lighting.

What causes paint "dandruff" ? :

You should know that there are basically two different kinds of plastic used to make latex paints in North America. Inexpensive paints use PVA, or Polyvinyl Acetate, which is the same plastic that's used to make white wood glue. More expensive paints use PMMA, or Polymethy Methacrylate, which is the same plastic used to make plexiglas.

One characteristic of ALL PVA paints is that they soften up and lose their adhesion when they get wet. Typically, this happens on the ceiling of a bathroom since warm moist air rises and forms condensation on the paint on the ceiling. You also find it in the corners where walls meet ceilings as these are the coolest areas in a bathroom because heat can be lost in two directions at the same time. Thus, condensation forms in these corners, so the effect on PVA paint would be most pronounced there and on the ceilings. If the locations where the cracking and flaking are worst in the areas I've described, then the problem is ENTIRELY because whomever's been painting the bathroom didn't know enough about paints to choose the best paint to use in a bathroom.

What you need to do is as described in a previous post (Sir Wired, I think). Just scrape the ceiling down to remove anything loose, then apply thin coat of joint compound to the ceiling to fill in those cracks. You'll probably have to apply two coats of joint compound because joint compound shrinks as it dries, so you'll need a second coat just to fill in the shrinkage. (You're not wanting to cover the ceiling with a thin coat of joint compound; you're just wanting to fill in the crack gaps between the chips of paint that are still adhering well, so you need to thin your mud well (or spray it with water while it's on the ceiling).) Allow to dry, sand smooth, and then if it were me, I'd give it a coat of interior oil based primer, allow to dry, and then apply two coats of a BATHROOM paint like Zinsser's PermaWhite Bathroom Paint available at most home centers.

I wish I had a nickel for every person who has cracked and flaking paint in their bathroom and has been told by someone that the problem was poor prep work prior to painting. It just isn't true. It's that some latex paints handle humidity and moisture and being wet much better than other latex paints. So, paint bathrooms with paints meant specifically for bathrooms, and you can't go wrong. That's cuz the people who make paint know way more about paint than you, and they will ensure that the stuff they use in their bathroom paint stands up really well to humidity and moisture and being wet.

The old paint on your walls was probably a PVA paint. By top coating it with a PMMA paint, you'll be protecting the underlying PVA paint from moisture enough to prevent it from further cracking and flaking. That is, the bathroom paint will serve as a "rain coat" to keep moisture off the underlying PVA paint.


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