The last tenants took so many showers that there is mildew on the bathroom ceiling, since they never bothered to crack open the window, to let the steam out.

I tried to clean it well, before starting to repaint tomorrow, but some of it did not come off, even with a stiff brush. I tried various bleach cleaners and had bleach itself. It looks better so I am thinking of just painting over it now but will the mildew come through the new paint job?

I have never had this issue before so not quite sure how to get it all off or if painting over it would solve the problem without it coming back through the new paint.

Cat

Cat, yes the spots will come thru latex paint.

First, bleach needs TIME to DWELL on the spot.

Bleach does not remove all spots.

Make certain it's well dried, then spray some KILZ on it. Let that CURE, not just dry.

Paint.

Sherwin Williams has a paint additive to retard the future growth of mildew on damp surfaces.

Unfortunately it is not easy to clean ceilings with bleach. No matter how careful I am, it gets to my hands through the gloves and runs down my arm. I have also come close to hitting my head on the ceiling so getting it in my hair will be next.

I tried using a mop too and that did not work very well either. I am afraid that spraying Kilz will result in getting more on me than the ceiling. lol.

Maybe some pro painter will comment on this:

I just got a publication in the mail from Behr Paint that they send to painting pros. There was an article on a product called Concrobium Mold Control that is available at HD. They say "It contains no bleach, ammonia or VOCs, ....

remains on the surface after it's used to provide protection from mold recurrence."

I do use concrobium and like it much better than bleach. Comes in a spray bottle (or a gallon refill jug). Spray on and let sit. Scrub with a brush and rinse. Let dry. Then spray some on and let dry on the surface before repainting. Not all stains will be removed (because they are stains) so you need to seal the stain with Kilz or Bin and let dry overnight before applying finish coat.

Concrobium is much easier to work with than bleach because if does not have the odor and toxicity issues. My stains did not come through the repainted ceiling and it's been a couple of years.