Short Answer
Contractors can identify visible signs of moisture-related problems but should not present themselves as specialists in every aspect of mold testing/remediation unless appropriately qualified.
Detailed Explanation
Roofing and exterior contractors can identify visible signs of moisture problems — water stains, wood rot, condensation, and visible mold growth in attics and on exterior surfaces. This is part of evaluating the building envelope and identifying the source of moisture intrusion. However, mold testing (air sampling, spore counts, species identification) and mold remediation (containment, removal, clearance testing) require specific training, equipment, and in some states, licensing. A roofing contractor who identifies mold during an inspection should inform the homeowner and recommend consultation with a qualified mold professional for testing and remediation, while focusing on correcting the moisture source that allowed the mold to develop.
Why It Matters
Understanding the limits of a roofing contractor's expertise ensures that mold problems are properly evaluated and remediated by qualified professionals.