Well, there's no window in this bathroom either but I do run a fan and sometimes leave the door cracked open a bit. The paint in the MBR bathroom has the same problem and it is a much more open space. I primed and used a satin paint in the MBR bath. I think I used Valspar that time, so I guess it's not the paint brand that's the problem. The only common denominator is me. LOL.

I left the door open a crack too and I then had those streaks on the master bedroom wall. I guess there's no way around it.

Wow, this isn't encouraging. I was planning on painting our master bathroom soon and was going to use Zinsser's 123 with BM's bathroom paint thinking it would be the best but it doesn't sound like it's worth the extra money for the BM paint now.

Sounds like the streaks don't wipe off?

Say there OP...

As Shee says, do your streaks wipe off!?!?

Unless you used Duration FLAT, temporary streaks are nothing to be even remotely concerned about. Higher-end paints like that aren't affected by temporary water contact.

Let ANY paint dry for ~ 24 hrs. b4 a load of steam hits the surface. FULL cure of the total paint-job can take a month however.

If streaks wipe off...NO concerns whatsoever.

Faron

"Water-whitening" can sometimes happen with latex-based coatings. Enough moisture makes its way into the coating film to swell the polymer particles, which normally are not 100% fused even though the pant has dried, resulting in micro-gaps which scatter light, thus causing the whiteness. It of course is not noticeable with white paints, but it can be with clear latex films, and with medium and dark colors. Tinted paints are generally made with more surfactants (soaps) than are white paints, which increases the tendency, because the surfactants increase water absorbancy by the dried paint. When the streaks dry out, the light scattering drops off, and may disappear altogether. As the shower is used over time, and condensation extracts the surfactants from the paint, whitening tendency will decrease." -John Stauffer, Technical Director, Rohm and Hass Paint Quality Institute

Water Whitening is a form of leaching but it's not the same thing as typical surfacant leaching that can look brownish, or like syrup. This leaching is completely clear and dries out and disappears within hours of it occurring.

I have noticed cheaper paints can let go of color along with moisture and surfacants. The better grades/brands recover from the water whitening quicker and they have a better chance of releasing the surfacants to the point of the problem completely going away with time.

It can look like the walls are bleeding in white streaks and people's first inclination is to wipe the walls. I kinda think the best thing to do is leave it alone. Make sure the bathroom is well ventilated, let it dry out naturally each time and just wait it out til one day it just quits happening.

Couple things I believe people don't understand about water whitening is it CAN HAPPEN WITH ANY PAINT or combination of primer and paint. Bathroom paint or 'regular' paint - it still happens. Oil primer under - it still happens, etc., etc. etc.

As I understand it - and have seen happen - if your top coat is prone to "normal" water whitening, it's going to happen regardless. Just have to wait for the surfacants to work out of the film.

I hate to admit it but I didn't try to wash off the streaks. I just assumed that it was condensation due to either poor paint or faulty application. I usually use flat paint, but I hadn't painted bathrooms until I did these two. The builder had used flat paint in the bathrooms previously and they didn't have the streaking problem then. I think he had someone spray it on - it was applied awfully thin and you could see parts of the drywall in some of the other rooms in the house.

I agree this is a condition of using cheaper paints, but I have done some experimenting in my own bathroom with high end paints over the years and have found that C2 fails, Benjamin Moore fails and Muralo fails...all high end paints. The only paint that has worked for me is Grahams Satin. Go figure.

Oh we just recently purchased a home,and this is happening in our spare bathroom. We've completely gone over every inch of the wall with baking soda and vinegar,and a week later,the streaks are back. They do wipe off,but these are brownish streaks look like nicotine on the walls,which are a darker shade of green,like moss green. Is there NO way to stop this? We do have a vent fan in there,just no window. I was thinking to clean it all down,let iti dry completely,paint it with Kilz,let that dry,then repaint the room. Does anyone know if this would help any? And would a lighter flat color be better?

They do wipe off,but these are brownish streaks look like nicotine on the walls,which are a darker shade of green,like moss green.

That's not water-whitening. Sounds like typical leaching, but I've only seen that one time and it was exterior not interior, so, I don't know. Hopefully others will chime in with info.

Yea if it's brown that mean surfactant leaching. Is it possible that the bathroom was painted recently and isn't completely cured? The leaching should eventually stop and will certainly help if the paint is totally dry.

I don't recommend this but I painted my bathrooms with Duration Exterior and no surfactant leaching for over a year.

I built a new house in Powell last year and this is what I did.

Primed new wallboard with GARDZ. Applied two coats of Duration Exterior in Thunder Gray.

Try GARDZ on your next bathroom project, followed by two full coats of Acrylic Enamel paint.

Help Anyone?? I am going to paint a customers bathroom. They have 6 kids that share this room and there is tons of streaking in the paint. It is a darker color paint. I am concerned that when I put tape on the wall the paint came off. We sanded the entire room and will be using the Ben Moore Bath and Spa paint. I haven't painted it yet and stopped because I wanted to do a little research since this paint is quite expensive. I was going to sand with a palm sander, prime, then paint. the Bath and Spa has a primer in it but didn't feel confident since the paint came off with scotch tape (that's all we had at the time)

Use a quality primer(Zinsser 123) and paint away .Don't let anyone take a shower for at LEAST 48 hours, double that would be better.

Traditionally, only semi-gloss or gloss paint would be used in a bath with shower due to the "surfactant leaching" which can occur in high humidity areas. In glossier paints, the white pigment is milled much finer, and thus pack together much more densely. This denseness also bars or lessens moisture penetration. This is also why gloss paints generally wash much better than low sheen paints, with their relatively loosely packed pigments. If moisture does not penetrate into the paint film, surfactant leaching cannot occur.

One paint that I regularly recommend for baths is Behr Ultra. Behr introduces another metallic particle into the Ultra paint which is of the several nanos dimension in size ( a nano is one billionth of a meter). Nano particles are so small that they are not "seen" by light ways, and thusly do not affect the color of the paint. This increases the density of the paint film and makes it extremely moisture resistant. A side benefit is that the dense paint film also becomes inherently mildew resistant, although all Behr paints include a chemical mildecide too.