Causes of mold on a bathroom ceiling
Bathrooms are one of the most common home locations for black and brown mould or mildew. Mold is caused by a fungal spore that enters the home and then reproduces to cover a large area. Bathroom ceilings are susceptible to mould because of the bathroom's ideal growing conditions for the fungus.
If you are able to identify the cause of the mould on your bathroom ceiling, then you can take the steps necessary to remedy the problem.
The very design and structure of a bathroom ceiling makes it an ideal space for mould to grow. Many bathroom ceilings feature low ceilings that trap air and humidity. Bathroom ceilings are commonly painted with a textured paint like sand or popcorn; the texture creates small pockets and grooves that serve as mould breeding grounds. Mold is also drawn to corners and spaces with shadows. Since ceilings join walls at angles around the entire room, mould is commonly found on ceilings where the ceiling meets the wall.
Poor Air Circulation
Sufficient air circulation have several benefits. In a bathroom, extractor fans or open windows allow damp air to escape the room to reduce dampness and humidity. Mold spores are a common component of the air, but typically moving air prevents spores from settling onto surfaces. If a bathroom space is not well ventilated or fitted with an insufficient fan system, mould spores have the opportunity to settle on ceiling surfaces and begin multiplying. Leave windows open and provide an adequate fan system in your bathroom to reduce the likelihood that mould will invade the ceiling.
Most bathrooms feature a central extractor fan with a low-wattage light bulb and a set of vanity lights. Bathrooms are typically comprised of a large space with several additional cut out spaces for things like vanities, showers, baths and toilets. The number of small nook-like spaces decreases the likelihood that all areas of the bathroom receive adequate lighting, especially ceiling areas. Mold thrives in dark spaces that hold in humidity, and so dark areas of the bathroom ceiling provide an ideal growth location for mould and mildew.
Bathrooms are a high-humidity area. Not only is humidity aided by showers and baths, but the small spaces hold moisture into the room. Steam rises and traps moisture on bathroom ceilings. When a mould spore rises with the air, it comes into contact with the warm, moist ceiling surface and begins to reproduce. Reduce bathroom humidity by providing adequate ventilation after showers and baths. If you notice that certain areas of the ceiling seem to be pooling water, wipe them down with a cloth to remove spores and prevent reproduction.