National Building Service, Inc. is a commercial cleaning service based in Knoxville, Tennessee since 1985. We specialize in professional and reliable janitorial cleaning for your business and industrial buildings, whether it's an office, school, church, or recreational park. We offer 24/7 emergency service for our regular customers, carpet and floor cleaning, strip and floor waxing, construction clean-ups, daily cleaning, and much more! Give us a call or visit our office today for more information!