Product Overview

Summary: This SOP sets out clear, practical steps for controlling moisture before, during and after plastering works to protect worker health, structural integrity and finish quality. It helps Australian construction and maintenance teams manage damp, mould, and material failure risks while staying aligned with WHS obligations and relevant building standards.

Moisture is one of the most common and costly causes of plaster failure, mould growth and indoor air quality issues on Australian building sites. Uncontrolled moisture can lead to cracking, delamination, efflorescence, corrosion of fixings, and unhealthy work environments, exposing workers and occupants to respiratory hazards and businesses to rework, disputes and potential non-compliance with WHS and building requirements. This Safe Operating Procedure provides a structured, step-by-step approach to identifying, monitoring and controlling moisture throughout the plastering process, from substrate assessment and site preparation through to curing, ventilation and verification checks.

Developed for Australian conditions, the procedure addresses the practical realities of humidity, rain events, flood-affected works, and tight construction programs. It sets out clear responsibilities for supervisors and trades, details the correct use of moisture meters and environmental monitoring, and prescribes control measures such as sequencing of wet trades, temporary weather protection, ventilation strategies and safe use of dehumidifiers and heaters. By implementing this SOP, businesses can reduce moisture-related defects and WHS risks, improve finish quality, and demonstrate a defensible, documented system of work that supports compliance with their duty of care and relevant Australian Standards.

The document is written in plain, site-friendly language but underpinned by WHS principles, making it suitable for toolbox talks, onboarding of new plasterers, and integration into broader quality and safety management systems. It provides a repeatable method that can be applied across residential, commercial and refurbishment projects, including remedial works in existing damp or flood-impacted buildings.

Key Benefits

• Reduce moisture-related defects such as blistering, cracking, mould growth and delamination in plaster finishes.
• Ensure safer working environments by controlling damp, mould and poor air quality that can affect worker health.
• Standardise moisture assessment, monitoring and sign-off processes across all plastering projects.
• Minimise rework, delays and client disputes arising from moisture damage or non-compliant finishes.
• Demonstrate due diligence with documented moisture control practices aligned to Australian WHS and building standards.

Who is this for?

• Site Supervisors
• Plasterers and Solid Plasterers
• Construction Project Managers
• Residential and Commercial Builders
• WHS Advisors and Safety Officers
• Facilities and Maintenance Managers
• Quality Assurance Managers (Construction)
• Building Inspectors and Clerks of Works

Hazards Addressed

• Exposure to mould spores and bioaerosols in damp or water-damaged areas
• Respiratory irritation from working in high-humidity or poorly ventilated spaces
• Slip, trip and fall risks from wet floors, wet materials and water ingress
• Structural and finish failures from applying plaster to substrates with excessive moisture
• Electrical hazards associated with using powered dehumidifiers, heaters and fans in wet environments
• Manual handling risks from handling waterlogged plasterboard or wet materials
• Condensation-related corrosion of metal framing, fixings and services behind plaster linings

Included Sections

• 1.0 Purpose and Scope
• 2.0 Definitions and Key Terms (Moisture Content, Relative Humidity, Dew Point, Curing)
• 3.0 Roles and Responsibilities (Supervisors, Plasterers, WHS Personnel)
• 4.0 Pre-Start Requirements and Planning (Weather, Programming, Site Conditions)
• 5.0 Required Tools, Equipment and PPE (Moisture Meters, Hygrometers, Dehumidifiers, Respiratory Protection)
• 6.0 Moisture Assessment of Substrates and Building Elements
• 7.0 Environmental Controls (Ventilation, Temperature and Humidity Management)
• 8.0 Moisture Control During Plaster Application and Curing
• 9.0 Working in Damp, Water-Damaged or Flood-Affected Areas
• 10.0 Use of Mechanical Drying Equipment (Dehumidifiers, Fans, Heaters) – Safe Work Practices
• 11.0 Quality Assurance, Inspection and Acceptance Criteria (Moisture Limits and Sign-Off)
• 12.0 Hazard Identification and Risk Controls Related to Moisture and Mould
• 13.0 Emergency and Incident Response (Water Ingress, Storm Events, Equipment Failure)
• 14.0 Training, Competency and Communication (Toolbox Talks and Inductions)
• 15.0 Recordkeeping, Monitoring and Continuous Improvement

Legislation & References

• Model Work Health and Safety Act and Regulations (as implemented in each state and territory)
• Safe Work Australia – Managing the Work Environment and Facilities Code of Practice
• Safe Work Australia – Construction Work Code of Practice
• AS/NZS 2589: Gypsum linings – Application and finishing
• AS/NZS 2311: Guide to the painting of buildings (for guidance on substrate moisture and preparation)
• AS 3740: Waterproofing of domestic wet areas
• National Construction Code (NCC) – Performance requirements related to moisture management, damp and condensation
• Relevant state-based WHS regulations for construction work and plant (e.g. portable heaters and dehumidifiers)