Cal. EDC § 17600

The governing board of any district defined hereafter, in addition to any other authority granted by law, may employ as classified employees, in accordance with rules and regulations established by the personnel commission, any certificated employees of the district or districts during vacation periods, or on any other day or days when the certificated employee is not required to perform services for the district, to repair or build apparatus or equipment related to their duties as certificated employees even though the total cost of labor exceeds one thousand dollars ($1,000). This section applies only when the average daily attendance of any school district, or of two or more school districts governed by governing boards of identical personnel, is 400,000 or more, as shown by the annual report of the county superintendent of schools for the preceding school year.