How To Repair Blistering Paint In Bathroom

[KC]

The paint in our bathroom (room dimensions 6'6" x 7') has begun to blister. The top layer of sand textured paint is blistering, beneath that is a white plaster-like coating approximately 1/8" thick, and then a pinkish colored drywall. It looks as though the blistering is occurring along the seam where two pieces of drywall are butted together.

The three inside walls are the ones with the blistering paint problem, and all three of those walls have either a hallway or a bedroom on the other side. The paint on the ceiling and the bathroom's outside wall is fine.. There is an exhaust fan in the bathroom. I do not know what capacity it is.

My questions are:

What is the proper method to repair these walls? Do I just repair the areas that have blistered, or do I have to strip down all the walls to drywall? How do I prevent this from occurring again? Get a bigger fan?

We have lived in the house for 7 years, and this problem only began this year.

Thanks in advance for any advice

KC

[AJScott]

About that exhaust fan: Does it vent to a distant point, like thru the wall to the outdoors or maybe the attic? Or does it just basically blow up into your ceiling, like it does with most peoples' bathrooms? If it's not directly vented out to somewhere else beyond your bathroom, that moisture from the daily hot-water showers basically stays collecting in your bathroom space, especially on the walls and ceiling. And hence most likely the reason for the blistering. In the interim until you find a permanent solution, you might try opening the bathroom window a bit while showering to let the steam (and moisture) out.

AJS

[KC]

Thanks AJ

The exhaust fan is vented to the outside. No chance of blockage on the outside because the air exits through a screened soffit panel. But it's been over a year since I checked to see that he air was coming through - I suppose it's possible something came undone in the venting. I'll check that out. Thanks for the suggestion.

KC

[R Doornbosch]

Do you think the plaster covering the joint is actually coming off or do you think it's just the paint? If you took a chip of the paint does it have several layers (One colour on top and a primer colour on the bottom)? You see it all to often that people spend a lot of money on great paint but have blown their budget so settle for cheap primer. Just a reminder when painting if the primer you put on the wall isn't going to hold why would you expect the paint on top of that to do any better?

I think I would scrap off the remainder of the loose paint / plaster add a thin layer of drywall mud to bring the paint up to the same height and then repaint or touch up the spots. Get rid of anything that's loose on the wall and consider giving the surrounding walls a quick light sanding before re-painting.

[Phisherman]

[KC]

Thanks for the advice.

To answer R Doornbosch question, what is coming off is the joint compound, or whatever they used between the joints of the drywall.

Regarding the repainting - I realize that I will have to scrape the parts that are blistering now, apply spackle or joint compound to get back to level, and prime and paint. However, the existing surface is sand textured. Is there any special process one needs to follow when preparing walls with this type of finish for repainting?.Do I have to find an alternate way of preparing them other than sanding? I just wonder what the sand texture finish is going to look like after I take a piece of sandpaper to it.

Not sure how I would find a leak in the walls - I don't see any evidence of one (other than the blistered paint). The only thing I can think of is that the duct for the fan came undone, and is pumping moist air into the space above the bathroom ceiling.

Did not know that the fan should run 30 min. after taking a shower. I'll get a timer. Thanks again for the advice

KC. .

[R Doornbosch]

1) IS the paint "sand textured" or was the wall sand textured? I've only seen the paint?

2) The spots that are coming off are they near the ceiling or half way down the wall? Is it only the one joint? Is there any chance that the drywall cracked on that joint because of bumping or movement from someone hitting the wall from the other side?

3) Once repaired I say use a high quality primer to seal everything good and then repaint it.

[KC]

The paint is sand textured.

No problems on the ceiling, which I would think would get it the worst since that's where all the steam goes.

The problem areas are halfway down the wall. It affects at least 3 different joints. No movement or bumping, on the walls,.. It just seems like the joint compound "lost its grip" and that's what produced the blister. I could be wrong on that. Hopefully applying new joint compound to the problem spots, priming and painting will solve the problem.

Thanks for the help.

[R Doornbosch]

If you have the space some compounds are better than others at repelling water. In some cases I've used Durabond 90 (Basically cement) to fill the gaps, but it's extremely hard and does not sand very easy so be careful. I would highly recommend a good primer and possible oil paint to repel the steam or water wrecking the walls. Can't say much more without actually seeing the problem.