Mold is one of the most prevalent micro-organisms within a home as well as one of the most dangerous. Molds release tiny spores, and when these spores land on a wet area, they grow. Because mould needs a moist environment, it is mostly found in bathrooms. Providing ventilation to keep a bathroom dry was once the only method of preventing mould, but wall treatments that resist mould are now available.
Some paints are designed to prevent mould growth. These paints contain anti-fungal agents that will prevent mould that becomes attached to the wall from growing or reproducing. It is important to note that these paints will not kill any mould that is already present, so it is crucial to thoroughly clean all walls to remove any mould before painting them with mould-resistant paint.
Anti-fungal agents can be added to paint that is not specifically designed to be mould-resistant. When doing this, it is important to follow the directions carefully because too much of an anti-fungal agent per gallon of paint can be toxic. Also, these additives work better with less porous paint; the more gloss there is in a paint, the less porous it is.
Tile is one of the best surfaces for the prevention of mould and mildew. Glazed or sealed tiles provide the mould with no food source. If the tiles are not glazed, it is best to apply a sealer to the tiles if you are tiling a bathroom.
The main source of mould on tiled walls is on the grout between the tiles. Grout is very porous when dry, and this allows it to absorb water, providing the ideal conditions for mould growth. Some grouts have anti-fungal additives in them to prevent mould growth, while other grouts have latex additives that reduce the absorbency of grout. Using one of these grouts would reduce the chances of mould growing in the grout.
Sealing the grout will also prevent mould growth. It is important to seal the grout only after it has had time to dry, usually 48 hours. Two types of grout sealer are available: membrane-forming sealers and penetrating sealers. In a room with high moisture such as the bathroom, only penetrating sealers will prevent mould. Membrane-forming sealers may prevent mould for a while, but if any water leaks past the sealer membrane, it will not be able to dry and will begin to grow mould. Penetrating sealers provide a deeper seal that is able to dry.