Human Resources Administrator

Job Summary

Oldcastle Infrastructure is seeking a highly organized and proactive HR Administrator to support our DBD4 operations team. This role serves as the administrative backbone of the business, ensuring efficient office operations, supporting field and management teams, and helping coordinate key business processes across operations, HR, accounting, and customer support functions.

The ideal candidate is a self-starter who thrives in a fast-paced environment and enjoys wearing multiple hats. This position offers the opportunity to grow and learn various aspects of the construction and infrastructure industry, including contract administration, billing support, compliance tracking, employee onboarding, and customer service.

Job Location

• This position will be on site at our office in Mesa, AZ.

Job Responsibilities

• Manage daily office operations and administrative activities.
• Serve as the primary point of contact for office visitors, employees, customers, and vendors.
• Assist with employee onboarding, new hire paperwork, and general HR administrative support.
• Support payroll tickets and timekeeping processes.
• Coordinate and maintain employee files and confidential records.
• Assist with customer contracts, subcontract agreements, and project documentation.
• Request, track, and distribute Certificates of Insurance (COIs).
• Support preliminary lien notice and compliance processes.
• Assist with project billing, invoicing, and administrative project closeout activities.
• Maintain office supplies, equipment, and company records.
• Support document management and electronic filing systems.
• Coordinate meetings, schedules, and company communications.
• Provide administrative support to the Director of Operations, HR and field leadership teams.
• Assist with special projects and other duties as assigned.

Job Requirements

• 3+ years of office management, administrative, operations support, or related experience.
• Strong organizational and multitasking skills.
• Excellent verbal and written communication abilities.
• Proficiency with Microsoft Office Suite, including Outlook, Excel, Word, and Teams.
• Ability to manage confidential information with discretion.
• Strong attention to detail and follow-through.

• Experience in construction, infrastructure, contracting, engineering, or industrial operations is preferred.
• Experience with billing, invoicing, contracts, payroll support, or compliance documentation is preferred.
• Knowledge of Certificates of Insurance (COIs), lien notices, or contractor documentation is preferred.
• Experience with ERP, HRIS, or project management systems is preferred.