How long do mold test results take Mold test results usually take 24 to 48 hours. Once the lab sends results back, GreenRoom Remediation reviews the report with you and creates a step-by-step plan to remove the mold and stop it from coming back. Mold Testing| Share This Story, Choose Your Platform! FacebookXRedditLinkedInWhatsAppTelegramTumblrPinterestVkXingEmail