It is always better to be proactive than reactive. If you are looking for a house to buy, you must check out every nook and cranny to ensure that there is no mold anywhere. Getting a house that is infested by black mold or any other mold cleaned can become quite a costly affair, and home insurance companies generally reject any claims for mold cleaning.
In your own house, you must do a periodic inspection to ensure that there is no mold. Air ducts, heating systems, roof tiles, window edges and cupboards through which there are pipes running are places which usually get infested by black mold. You cannot tell which type of mold is it unless you have it tested in a laboratory. It again becomes a costly affair; therefore, the best option is to clear out any mold that is in the house.
If you live in a humid area, that is where black mold thrives the most; you should monitor the humidity level in your home. The humidity level in your home should never exceed 55% RH. Anything above this will be an ideal breeding and thriving atmosphere for black mold and other fungi and dust mites.
To check if you have a humidity problem in your home, you must invest in humidity sensors or a hygrometer. You should place the moisture meter at places that you suspect have a high humidity level. You can move the meter around and check the moisture levels in various areas of the area. In case the humidity level is high, you would need to get a dehumidifier installed. You can get multiple dehumidifiers installed in various rooms of your house.
You should check for water leakage/seepage and rusty pipes. Nowadays, most pipes in houses are concealed and it is difficult to check for rusty pipes and leakages. The only way to check for leakages is to listen if you can hear water running when the tap is turned off. If you hear water running or smell a musty odor, you can expect for fungi to thrive in these areas.
If you have a leaking tap or toilet, or discolored damaged walls, these are the places where black mold can grow. The best way to ensure that your house stays free from any type of fungi growth is to keep the humidity level within prescribed limits and check your home regularly to ensure that there is no fungi or black mold spots in your house.