Drippy, icky bathroom fun!

May 6, 2008 7:31 PM

Mold and bleach? How much to kill it, but not me? (And I guess not my roommate, too.)

I've got some seriously moldy bathroom walls. This is a rental home, and I'm looking quite forward to moving out of it in the fall.

I'm looking for an easy, inexpensive solution to getting the mold off. Past askmetafilter questions say to wash the walls with bleach (straight?) or a bleach solution. Well... color me ignorant, but is it safe to simply spray the walls w/ bleach? If I need to make a solution, is there a standard bleach/water recipe?

Basically, this bathroom hardly ever dries. So, if the wall hardly ever dries, I have concerns about the walls being bleach and stinky the next time I take a shower after I clean it - possibly to an unhealthy, annoying level. Not to mention brushing against the wall with fabric and ruining it.

Am I being paranoid? I feel like a total cleaning n00b.

posted by fillsthepews to home & garden (21 comments total)

What type of surface? (tile, painted drywall, etc.)
posted by winston at 7:42 PM on May 6, 2008

Seconding what kind of surface. It is likely perfectly fine to spray the walls with bleach, though, either straight or dilute.

The important thing is ventilation when using bleach. It sounds like you have a problem with that already. What you need, my friend, is a fan. If there is no surface on which to put a fan, put it on the floor in a place where you won't trip on it. Do your best. This may be a PITA. It will also keep mold from growing on your walls and allow you to clean them with bleach without choking.
posted by desuetude at 7:57 PM on May 6, 2008

Mary Ellen (a cleaning expert) says "To clean bathrooms, tile and vinyl floors, make a bleach solution combining 3/4 cup bleach to one gallon of water." If it is not tile or vinyl, you may mess up the paint and/or drywall so (a) don't soak the wall and (b) test in a very inconsipcous spot. (behind the toilet?)
Also, you don't just spray the bleach on. Let it sit (15? 30? minutes) and scrub the mold off with a scrub brush. Open the windows and turn on a fan, both to protect yourself from fumes and to dry out the room.
posted by metahawk at 7:59 PM on May 6, 2008

I apologize for not answering the part about cleaning, but you might consider installing a higher grade fan and running the fan all the time. (You could also install a humidistat, but that might be too big a job for a rental home that you're planning to move out of in 6 mo.)
posted by acoutu at 8:15 PM on May 6, 2008

Um, in terms of what surface its probably an "oil based" or "plastic based" paint. Typical cheapo bathroom glossy paint.

It is hard - I dont exactly love living in mold, yet I'm not willing to put too much work in it.

Thanks everyone for your reccomendations. There is definetly no surface to put a fan on, hah. I will do my best not to die.
posted by fillsthepews at 9:00 PM on May 6, 2008

Oxiclean (or another other brand of oxygen-based cleanser) is a much safer option if you're worried about bleach. Here's part of the product review when used for cleaning mold:

Mold and mildew stains are organic and the cleaner works very well on those. Anyway, we mixed it with just a little hot water and made a thick paste. We applied it to the stains and let it stand for a short while. We then rubbed the stain with a sponge and it started coming off. The stain did not come completely off in some places so we repeated the procedure once again until it all disappeared. So far, so good.
posted by amyms at 9:00 PM on May 6, 2008

Definitely ditto what acotu said about a fan. Since it's a rental home you probably don't want to go to the trouble of installing a ceiling fan. You can do what I did, and get a small wall-mount fan. We installed this in the bathroom without much trouble, and it really cut down on the post-shower humidity. You could also put a standing fan in there, blowing out the door.
posted by radioamy at 9:08 PM on May 6, 2008 [1 favorite]

Straight bleach seems a little strong. Most instructions call for diluting it somewhat, usually considerably, such as the 3/4 c to gallon listed above.
posted by fructose at 9:12 PM on May 6, 2008

I have used 4 parts water: 1 part bleach in a spray bottle. OPEN THE WINDOWS. Spray affected areas liberally. Close the door. Next morning, mold is gone, rooms smells bleachy. Leave windows open and enjoy. My paint was fine, I got bleach on a good tshirt (dumb). Your bathroom needs much better ventilation if it's always damp.
posted by theora55 at 9:16 PM on May 6, 2008

If you prefer to stay away from the bleach then you can use vinegar to kill the mold. Do NOT try the vinegar after you've tried the bleach or vice versa. Bleach + Vinegar = BAD fume mojo

Whichever one you chose to use, I'd try it out first on an inconspicuous place on the wall like behind the toilet or under the sink.
posted by GlowWyrm at 9:23 PM on May 6, 2008

chose=choose...I can't spell. :)
posted by GlowWyrm at 9:24 PM on May 6, 2008

A very low concentration does a great job. Add a little vinegar as well for an even better low concentration efficacy.
posted by caddis at 9:41 PM on May 6, 2008

Oh, the order of dilutions is important. First dilute the bleach in water and then add the vinegar. Adding the vinegar and bleach together without first adding the water might release some chlorine gas, not good. Anyway, adding an acid (vinegar is one) to bleach is always a risk, but when mixed with a dilute bleach it makes a super potent mold killer. Vinegar and hydrogen peroxide is probably even more potent for general bacteria including spores (I am not sure whether it beats the bleach/vinegar mixture with mold but it will nuke mold quite well) and it is safer in the released gas department.
posted by caddis at 9:54 PM on May 6, 2008

Spraying the bleach gets horrifying amounts of fumes in the air. A mop is an easy way to apply the bleach. Mop again with plain water after a bit to wipe the bleach off the walls.
posted by yohko at 11:12 PM on May 6, 2008

long term, look at getting a dehumidifier.
posted by Dillonlikescookies at 2:59 AM on May 7, 2008

Best to just wash the walls with soap and water to remove the mold. Then rewash with a vinegar and water solution.
posted by zia at 3:55 AM on May 7, 2008

I'm guessing, in light of caddis's last comment about adding vinegar to bleach, that GlowWyrm was thinking of ammonia + bleach, which IS a horrible mix. Noxious chlorine gas! Avoid!
posted by Stewriffic at 4:52 AM on May 7, 2008

I had a bit of mold in my bathroom, I did a 5:1 water/bleach mix and it instantly made the mold go away. The mold was very very mild though, just a few splotches about the diameter of a pencil.
posted by substrate at 6:07 AM on May 7, 2008

Stewriffic,

No I was thinking of vinegar and bleach. If you mix vinegar and bleach you can create dangerous fumes. But as someone mentioned earlier, if the bleach is diluted enough it won't be a problem. I still do not recommend mixing bleach and vinegar especially if you are not going to dilute the bleach with water as it will result in chlorine gas.

bleach + ammonia = bad

bleach + vinegar = bad
posted by GlowWyrm at 6:09 AM on May 7, 2008

Thanks, everyone! This is just the sort of info I needed. Hopefully, I'll attack this over the weekend and report back :D
posted by fillsthepews at 9:49 AM on May 7, 2008

Just attacked my own mold bathroom mold based on some of the advice here. Vinegar did nothing, but some Tilex mildew/mold remover (almost all bleach, far as I can tell) worked great. One application and 90% of it just disappeared. But the smell is really strong. Open a window, turn on a fan, and prepare to leave for a while.
posted by meta_eli at 7:39 PM on June 12, 2008