Masonry Cleaning & Caulking SWMS

Masonry cleaning and caulking involves the post-construction restoration of brick, block and stone facades — removing mortar smears, efflorescence and construction residues using acidic wash-downs (typically hydrochloric-based proprietary cleaners), high-pressure water, and mechanical abrasion, followed by the application of polyurethane or silicone sealants to control joints, perimeter penetrations and expansion gaps. The work is hazardous because it combines corrosive chemicals, respirable crystalline silica liberated during dry cleaning, working at height on swing stages or scaffolds, and isocyanate exposure from polyurethane sealants. Chemical burns, silicosis, falls and eye injuries are the dominant acute and chronic risks.

Under the Work Health and Safety Regulation 2025 (NSW), this work is high risk construction work where cleaning or caulking is carried out at a height exceeding two metres (section 291(a)). Section 299 requires a Safe Work Method Statement to be prepared before the work commences, kept accessible, and complied with. Controls follow the hierarchy — eliminating dry cleaning where wet methods suffice, substituting less hazardous acid alternatives, engineering edge protection, and mandating chemical PPE and RPE.

Hazards identified

12 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Eliminate work at height where possible by completing cleaning and caulking from a mobile scaffold or EWP with full edge protection rather than ladders; ladders prohibited for continuous acid application above 2 m.
2. 2Substitute concentrated hydrochloric acid cleaners with the least hazardous product that achieves the finish (e.g. buffered or citric/phosphoric alternatives); verify against manufacturer SDS and record substitution decision.
3. 3Engineer edge protection on all working platforms compliant with AS/NZS 4576 and AS/NZS 1576 (scaffolding) and AS 2550.10 (EWPs); toeboards and mesh infills fitted to prevent tool drop.
4. 4Use wet-cleaning methods to suppress silica dust; where mechanical removal of mortar is required, use tools fitted with on-tool extraction (M or H class) compliant with AS/NZS 60335.2.69.
5. 5Bund and contain acid run-off using absorbent socks and neutralising agent (sodium bicarbonate); protect stormwater pits before acid application; dispose of neutralised waste per EPA guidance.
6. 6Establish a facade exclusion zone at ground level with hard barricades, spotters and A-frame signage; overhead protection (gantry) where public access below cannot be eliminated.
7. 7Chemical PPE to AS/NZS 1337.1 (goggles + face shield), AS/NZS 2161.10.1 (chemical-resistant nitrile/neoprene gauntlets), acid-resistant suit, and P2 respirator to AS/NZS 1716; full-face air-purifying respirator with acid gas cartridge during pressure rinsing of acid.
8. 8Fall arrest as last resort: harness and lanyard compliant with AS/NZS 1891.1 anchored to certified points; rescue plan documented and equipment available on site before work commences.
9. 9Isolate 240 V electrical equipment through a portable RCD tested to AS/NZS 3012; inspect leads before each shift; keep electrical items clear of wet zones.
10. 10Emergency provisions: eyewash and copious water source within 10 m of acid work; SDS accessible on platform; first aider identified; nearest hospital route documented.
11. 11Schedule acid work outside peak heat (before 10:00 in summer); implement work/rest cycles per the SafeWork NSW managing the risks of working in heat guidance; provide cool water and shaded rest area.
12. 12All workers hold CPCCWHS1001 (White Card), have received site-specific SWMS induction, and are competent in scaffold/EWP use and chemical handling. Consult workers under section 47 of the WHS Act during SWMS development and review the SWMS under section 302 whenever the platform, chemical or crew changes, or after any incident.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

A bricklaying subcontractor is engaged to acid-wash and caulk the four-storey brick facade of a new mixed-use development in Wollongong. Work is carried out from a swing stage suspended 11 m above a public footpath. Before mobilising, the SWMS is completed with the crew of three, identifying the s291(a) fall risk, the hydrochloric acid cleaner (SDS reviewed), and the polyurethane sealant. Controls include a substituted buffered acid product, full chemical PPE with air-purifying respirators, a hoarding and spotter at footpath level, neutralising agent bunded at each stormwater pit, and harness back-up anchored to certified davits. On day two, forecast temperatures reach 36 °C; the supervisor reviews the SWMS under section 302, reschedules acid application to 06:00–10:00, and records the amendment. All workers sign on, hold current White Cards, and the SWMS is kept in the site box accessible to the SafeWork NSW inspector who attends unannounced.

Related legislation

• Work Health and Safety Act 2011 (NSW)
• Work Health and Safety Regulation 2025 (NSW)
• Protection of the Environment Operations Act 1997 (NSW) — acid run-off and stormwater
• Environmentally Hazardous Chemicals Act 1985 (NSW)
• Poisons and Therapeutic Goods Act 1966 (NSW) — scheduled chemical handling
• Dangerous Goods (Road and Rail Transport) Act 2008 (NSW) — transport of acid concentrates

Frequently asked questions