Bathroom Vents, Mold, and Wet Laundry
Some homes these days are taking to putting carpet into the bathroom, but this is a serious mistake. No matter how careful you are, the toilet, bath tub, or sink will eventually overflow and both your carpet and padding will be completely soaked in water. If you do happen to have carpet in your bathroom and have no intentions of removing it, get ready for a mold hazard. If the carpet and padding get wet and are not completely dried as soon as possible, mold will start to grow under it. Once carpet padding gets molded, it has to be thrown away. There is nothing else you can do. The best advice is to take up the carpet and have tile installed. This creates a waterproof barrier over your wooden floor.
Leaving damp rags, towels, or clothing on the floor anywhere is a bad idea and these items need to be washed as soon as you can, since if you leave them unattended for more than 48 hours, mold can start to grow on them. Leaving them on a floor that is carpeted and then covering them up with dry clothes is even worse, since you will probably forget about the wet items and neglect to wash them. This will cause mold to grow on everything in the pile, including the carpet and padding. Clothes should be put into a hamper instead of on the floor and dry clothing should never be put on top of wet.
Keeping the humidity down in the bathroom can also be a big problem, especially if you do not have an exhaust vent installed so that steam can escape. The water vapor adheres to the ceiling and is absorbed by it, causing it to be almost continually moist. This is the perfect environment for mold to grow in and if you do not have an exhaust fan installed, this is something that you should invest in, especially if you are going to remodel the bathroom to remove the infection, anyway.