How can i be sure the mildew in my shower is killed before i paint over it?

Question

i heard something about bleach, is that a liquid or powder?

i have a powder can that says "contains bleach" is that good enough?

Answer 1

get a bottle of clorox and spray all over the wall

Answer 2

The foolproof, professional way is to use a mix of TSP, bleach and hot water.  You mix it up carefully following the directions on the back of the TSP box.  Wear rubber gloves and old clothes and keep the window open.  The stuff is nothing to play with but it gets the job done.  It tears through really bad mildew that Tilex etc. won't touch.  If the paint is already coming up, it may take some of it off as you scrub, but that's actually a good thing, because you don't want to be painting over stuff that isn't properly adhering to the wall already.  Just sand it smooth after it dries and you'll be fine.  TSP is what professional painters use to prep the surface before they paint and a good paint job is almost entirely about the prep, so don't skimp on getting the surface perfect before you start.

To help keep the mildew from coming back, I would use a primer with mildew agents specifically formulated for bathrooms.  Killz or Binford both make them, but there are other brands as well.  If you can't find it at the home center, go to a regular, free-standing paint store (you'll get better paint there too, the stuff in the home center is cheap, but this is somewhere where you definitely get what you pay for).  You can also get anti-mildew agents added into your final coat of paint as well, and make sure you use semi-gloss paint that easier to wipe down.

Finally, the ultimate cause of mildew in your bathroom is insufficient ventilation.  You need to get that warm moist air out of the bathroom after a shower or you will have to keep fighting this battle interminably no matter how good a job you do now.  If you don't have a bathroom fan, get one.  If you do have one, it isn't being used enough. I suggest investing a little money in a timer switch that will automatically run the fan for some pre-set time (30 minutes or whatever) and then shut-off.  You want it to run long enough both to dry out the bathroom as well as get the moisture out of the ducts between the fan and the outside.  

If you do all that, your mildew problem will be permanently banished.

Good Luck!

Answer 3

Yes bleach is the best method for killing mold