Alertdoor

Alertdoor, formally Alert Door Service, inc., installs and repairs garage doors and garage door openers, swinging and sliding gates and their motors, commercial sectional and rolling doors and grilles, and hollow metal pass doors. The company has been serving the Peninsula since 1980 and is family-owned and operated, with three generations in the business.

Commercial and residential customers can request a free estimate by phone. Office hours are weekdays during the day, and the company offers 24-hour emergency service. The office is at 925 N Amphlett Blvd. in San Mateo.