Humidity is the root cause
Mold needs moisture, and Fayetteville's summers supply plenty of it. NOAA counts about 768 hours in an average year when the wet-bulb temperature at Drake Field is above 73°F, and about 2,152 hours above 67°F. The 1% summer design condition is 92°F with a coincident wet-bulb of 75°F. That is muggy air that finds its way into crawlspaces, attics and basements. A mold problem almost always means a moisture problem, and remediation that doesn't fix the moisture will be followed by more mold.
Where it shows up
The usual places in a humid climate are crawlspaces with bare dirt floors or vents that let in summer air, basements below grade, attics where bath fans dump moist air, closets on exterior walls, and around air handlers and ductwork where condensation forms. An air conditioner that is too large for the house, short-cycling without removing enough moisture, can keep indoor humidity high even when the temperature is comfortable. If the whole house feels damp, ask an HVAC contractor to look at the system alongside the mold work.
After floods and leaks
Heavy rain can turn a dry house into a wet one fast. NOAA lists a 100-year rainfall rate of 3.7 inches per hour for Drake Field, and the National Weather Service recorded a September 24, 2019 flash flood that flooded several Fayetteville city trails and led to at least two water rescues. Wet drywall, carpet and insulation that aren't dried within a day or two in warm weather are prime mold sites. If you've had water in the house, start drying immediately and keep the space closed with dehumidifiers running.
How remediation should work
For larger areas, follow the approach in the EPA's mold guidance and industry standards such as IICRC S520:
- Find and fix the moisture source first.
- Contain the work area with plastic sheeting and negative air pressure so spores don't spread.
- Remove porous materials that have grown mold, such as drywall, insulation and carpet, rather than just spraying them.
- Clean and dry structural wood and hard surfaces.
- Confirm the area is dry before rebuilding.
Spraying a coating over moldy material without removing it or fixing the moisture is not remediation.
Testing, and who does it
Testing can help in some situations, such as hidden mold or a dispute, but visible mold doesn't need a lab to confirm it. If you do test, consider using an assessor who isn't also selling the remediation, so the same company isn't both diagnosing the problem and profiting from the fix.
Before you hire
Ask for a written scope that names the moisture source, the containment plan, the materials to be removed, and how the company will show the area is clean and dry at the end. Ask about protecting the rest of the house, especially the HVAC system, during the work. A remediation company should be comfortable explaining why each step is needed.