Prevent Mold in Bathroom

How can I prevent mildew in my bathroom?

By far the most important mildew control remedy is to increase the ventilation in the bathroom. Leave the bathroom door open after you shower or bathe, and use the bathroom exhaust fan. If you live in an older home without an exhaust fan, install one, and be sure it is vented to the outside, or you may transfer your mildew problem to the attic!

Existing mildew on most surfaces can be killed with a mixture of 50% household chlorine bleach with 50% water. Use a hand sprayer to apply it to the surface, allow it to remain for a few minutes or until the blackish, dirty-looking mildew color disappears and then rinse thoroughly with water. If the surface is covered with soap scum, the mildew might be more difficult to kill. In that case, perform a thorough cleaning first with either TSP, a TSP equivalent or a commercial soap scum remover. Then use a mildew wash, even if it "looks" as though the mildew is all gone.

There are commercial cleaners that combine bleach with a cleaning product. I have found them to generally be less effective at killing the mildew so my advice is to keep your killin' and cleanin' separate!

Unfortunately, the mildew will return eventually unless you seal the walls by proper repainting. Mildew attack increases the porosity of the paint film, making reinfestation a certainty. Applying the proper paints after killing the mildew will assure longer-term mildew resistance.

By the numbers

Kill all mildew using bleach, as described above. Wash all walls with a prepainting detergent such as Soilax. If the ceiling is a spray texture ceiling, do not attempt to wash it or the texture will come off. If the texture is mildewed but still firmly attached to the ceiling, spray the bleach solution, let it dry thoroughly, and then continue to the next step, priming.
Let the surfaces dry thoroughly and then prime the affected walls completely with one coat of an oil based, fast drying primer such as Kilz.
After the primer is dry, finish painting the walls with two coats using a semigloss or eggshell finish latex paint, or a specially formulated bathroom/kitchen paint. Because of its limited washability, flat wall or ceiling paint is not recommended in bathrooms, especially where it will be directly exposed to water such as around the top of a tub or shower enclosure.
The paint you choose must be treated with a mildewcide which you can purchase at the paint store. Do yourself a favor... have your paint store add the mildewcide for you before shaking the can... it is difficult to evenly mix the mildewcide by hand! The exception would be bathroom and kitchen paints which normally have a mildewcide in their formula, making extra additives are unnecessary.

Mildewed caulk and grout in tubs and showers often resist bleach and other cleaners. Why? Because the mildew is growing inside the caulk or grout ! The only way to fully eliminate it is to remove the old caulk and replace it with a mildew-resistant caulk designed for bathrooms. Ditto for the grout, except you should replace it with a latex-fortified grout. These newer grouts are much less porous than old style cement grouts and more strongly resist mildew!