Bathroom walls sweating after/during shower??

Hello all,
I just renovated my bathroom and just noticed tonight that I have moisture spots on my walls that have discolored my bathroom specific latex paint from Valspar(LOWES). I have been noticing that after a shower the walls do look like they are sweating so to speak. I have an exhaust fan rated for a room up to 85sq. ft. if I recall. My bathroom is roughly 8.5 X 9.5. That is 81 sq. correct!! It is a light/fan combo and the globe covers 95% of the fan opening. There is just a little area above the globe that is open. I thought I installed it wrong but nope! Do I need a new fan?! It is mounted in the center of the room, and the exhaust hose runs about 6ft. then up to the ext. wall of the house about 1.5ft off the floor. ANY INFO?? SUGGESTIONS??
Thanks

 

How long was the paint allowed to dry before the shower was used? Is this a deep/dark color?

 

The "sweating" is just condensation on the bathroom walls. It is normal and expected just after a shower. To reduce it, you will need a more powerful fan. I wouldn't touch those "ratings" with a 10ft pole. Get the biggest fan you can, at a noise level you can stand. However, even a large fan is not going to eliminate the condensation entirely.

SirWired

 

Don't shut off the fan right after the shower is over, let it run another 20-30 minutes to remove the moisture.

 

What was the manner/type of renovation?
(What I'd like to know is, if this is new drywall or a repaint, a possible wall covering removal, and what steps were taken in whichever case that it was)

Are they moisture-looking spots or actual drips of water?

How long ago was this?
How long was the room painted before use?

 

The renovation consisted of removing all the lath and plaster! THAT SUCKS!!!!! Removed all blown in insulation from the only exterior wall and ceiling and reinstalled the good pink stuff, new drywall, tub, vanity & top, light fixtures, plumbing fixtures, and trim. Everything but the toilet was renovated!!
Paint was allowed to dry about 20 hrs or so. Maybe more. The marks in the paint now look like water runs that are stained into the paint. THey are a lighter green than the OLIVE GReen my wife picked out. It is a dark color, kinda like a hunter green. I have been noticing the condensation on the walls after showers starting last month. Bathroom has been done since early Oct.! I am still installing the trim.
I talked to a couple of people at work and they said I need a bigger fan and that the ratings of CFM on the box are a joke!! Also the size of sq. ft. that it will cover is a joke.
So I guess that is my problem. I just hope for the life of me that I can get the one I have out and get a new one in w/o messing w/ the drywall. It took me about 4 hrs to install that stupid fan. From mounting to electrical to running that crappy duct work that falls apart on you if you tear it so slightly!!!! I am going to check one last thing tomorrow and that is if the louvers on my ext wall mounted cover are opening when I turn the fan on?? They did when I checked it about 2 weeks after install which was mid Oct. THANKS FOR ALL THE HELP!!! I appreciate it and I am going look into all the suggestions!!!

 

Sounds like you are on the right track. It is also possible that the paint is prone to have this problem because of the deep tint. I've used very little valspar paint but generally the coatings sold at a big box are there because of a competitive price. Better paints can be gotten at a real paint store [SWP, B.Moore, etc] While higher priced, quality coatings generally apply and wear better!

 

Here is what I have now, only it is a Hunter not a Harbor Breeze, but the specs are the same and the light is almost identical!! - http://www.lowes.com/lowes/lkn?actio...203&lpage=none

What about these two?? They are 20cfm's more than the one I have.
http://www.lowes.com/lowes/lkn?actio...674&lpage=none
http://www.lowes.com/lowes/lkn?actio...750&lpage=none

That means I would have to get just a light and mount that in the spot I have the fan/light now and then install this in a different spot?! Is this a bad or good idea?? I am befuddeled!! No idea how to spell that!! LOL

 

me either but I know what you mean

I don't know a lot about exhaust fans but I'm sure the more cfm the better. Assuming you have attic access it shouldn't be too hard to wire in another light.

 

The specs on that fan are a little shy of what your bath should have, so an upgrade is in order
I have the NuTone version of that fan myself, the recommended room size on it is 6X7 (42 sq. ft.) @ 70 CFM (which is what that one is)
So yes, over-spec'ing the fan is a good idea
And it looks like the retailer is being generous with the sq. ft. specs

However, that's no bath paint and upgrading the fan won't cure your leaching/moisture wall/paint problem
The deep tint is also causing problems
(most bath paints can only be tinted lights and pastels, even a medium is pushing it)

I'd also recommend a paint upgrade
The bath specific paints from either Ben Moore or Sherwin Williams would be a better choice

With a Hunter Green...that's deep... real deep for a bathI would strongly recommend Aura (from Ben Moore)
The Aura is different chemically from other paints
You won't get these problems with the deep colors and weeping/blotchy/leeching bath walls

So, yes...an exhaust upgrade is in order, but along with a paint upgrade

 

Well I took a shower about 30 min ago and it is mainly the ext. wall that really has a lot of condensation on it. It is about 42 deg outside. Is this the problem. My interior walls also have cond. on them but no where near what it is doing on the ext.
Well the specs on the link I gave you of the one that is similar aren't the specs I have. I will look them up tomorrow.
If I recall the fan is rated for a room up to a 80 sq. ft. Thanks for all the help!
I don't think I will be repainting my bath by the way!! I am taking a course for a job promotion which is a lot of reading and testing, also have a 17 month old with another one due Jan. 10th so I am going to get the trim done and get the closet in the bathroom painted and new shelving installed along w/ working 50hrs a week. I have never been this hectic!!

 

From a lot of experience, the Sherwin Williams "Bath Paint" will eliminate the stains you are getting. This paint holds up like the Sears Tower. It will not stain or mildew on you. This coating is made for heavy moisture, condensation, like a steam room. It holds up guaranteed!. You will need to apply two coats and this coating is only available in the extra white base. No mid tone, deep or extra deep base is available. I am not sure just how dark Hunter green is but three coats may be in order. Or one primer and two finish. I have four kids taking at least two showers everyday and there bathroom is like the steam room at your local health club. Three years since I painted it and looks fantastic. There are runs if you look for them, but they wash off. One of the best products SW every made for residential.

 

Without a doubt it is the paint then
A proper paint would fix it
However, a fan upgrade could (should) lessen the appearance of this...possibly to the point that it's not an issue
But it is a paint thing really

 

Your fan is not enough.

It seems fans are rated for a cfm rating of dry air and are intended to remove stale air and odors.

Removing heavy, moist air that weighs much more before it has a chance to condense (sweat to some people) on the walls is a different story. Once it condenses, you have to have enough power and movement of dry air to evaporate everything from the walls before is can cause a reaction (stain, mold, etc.). - It takes a lot of air movement and a supply of dry air.

Dick

 

SW Bath Paint is indeed a great product. However, OP indicated that it's a Hunter Green color. Chances are that it would be in either the "deep base" or worst case, "Ultra Deep".

ANY Mfg's latex paint in either of these bases are going to be subject to the OP's complaint.

Technical term = Surfactant Leaching
Laymens Term = The colorants, and other substances can "rise" to the surface during periods of high humidity. In effect the moisture in the air is rewetting the surface. Hence 'runs' that look like wet paint. The deeper the color, the more pigment subject to rewetting.

OP also indicated a 20 hour dry time. Completely inadequate for the situation. Latex paint may "dry" in 4 hours or less, but its not "cured" for up to 30 DAYS. If moisture is introduced during this cure time bad things can happen as discovered by the OP.

Best course of action is to limit use in the bathroom for a week or so. If the "runs" cannot be removed with gentle scrubbing it may be required to reprime with BIN, and then use a high quality Bath Paint in a much lighter color. Preferrably the "white" base, as it contains many more active pigments than the color bases.

Good luck!

 

GB is right on

I'd like to add that (in my experience) limiting bathroom use (lowering the humidity) for a week...or four...at this point won't help
Although it certainly would have helped during the initial cure time (first week or more), the damage is now done, and although the spots may fade or be washed off during this time, the leaching will appear when (if) the humidity rises again

Also, due to the new type of surfactant in the Aura paints (Ben Moore), this is not a problem with them
(the polymers actual wrap the tints)
Admittedly, I haven't done a Base 4 in a humid bath yet to say from personal (professional) experience (it's still pretty new), but so far so good

 

(GB pokes his inflated ego into the room and says "as always") and bows back out...lurking again for the perfect question...