How to Check for Mold

Tools. You will need a flashlight. Even in good lighting, you need a bright light to make sure that you don't miss any discolorations. It is also a good idea to wear a disposable breathing mask and a pair of latex gloves. See the links below for more information on being able to identify mold and about mold testing.

Areas previously water damaged. If you have been flooded or had any leaks that you were aware of, these areas can have grown mold if the area was not immediately completely dried out.

Basement, crawl space and attic. Since these areas generally have the perfect combination of cool, moist air and darkness. The exterior walls are more prone to mold damage because of dampness seeping into the foundation. Also inspect any exposed wood that would probably be used for framing for black mold growth. Mold can weaken the supports and cause damage to the structure of your house.

Under the drywall/inside the wall/above the ceiling. If you have walls or a ceiling that is cracked, peeling, bulging or discolored, it has probably sustained water damage. This is absolutely an area that you will want to have tested by a professional or get a mold testing kit yourself. Toxic black mold often grows inside the walls with water damage and it spreads quickly.

Under the baseboards. If you have had water damage on your floor, do not overlook the possibility that water seeped up behind the baseboards.

Floors. Carpet in particular can be a breeding ground for mold and mildew if it has been wet through and sat for any amount of time. Keep in mind that even if you vacuum out moisture from the carpet after major water damage, the padding doesn't have any ventilation to dry properly in most cases. Tile can also harbor mold in grout and under tiles with adhesive.

Beneath/behind toilets and sinks. There are often small leaks in these places that can cause major mold damage over time.

Heating/cooling systems. Both your ductwork and the furnace are particularly susceptible to mold. The most common places for standing water to create an environment for mold is the drain pan, cooling coil and a humidifier if you have one built into your furnace. If you suspect you have mold growing in your system, contact a professional HVAC technician for assistance.