The average maintenance salary at Sherman Isd was $42,031 , which is 16 percent higher than the average salary for this job in Texas, but 8 percent lower than the national average for this job . Maintenance salaries at Sherman Isd typically range from $28,704 to $48,194 (25th to 75th percentile). The highest reported maintenance salary was $91,127. There are 17 employees at Sherman Isd with the job title maintenance.