Chemical Adhesives, Grouts & Waterproofing in Wet Areas: COSHH and Method Statement Requirements for Tiling Contractors

Table of Contents

• Introduction: Why Tiling COSHH is More Complex Than It Looks
• Cementitious Adhesives and Grouts
• Epoxy Adhesives and Grouts
• Waterproofing Systems and Tanking Products
• Silica Dust from Tile Cutting
• Confined Space and Ventilation Considerations
• What Your COSHH Assessment and Method Statement Must Cover
• Frequently Asked Questions

Introduction: Why Tiling COSHH is More Complex Than It Looks

Tiling contractors routinely work with multiple hazardous chemical products on the same project. Cementitious adhesives, epoxy grouts, liquid waterproofing membranes, and silicone sealants all carry different hazard profiles and require different controls. A COSHH assessment that simply lists "use gloves and work in a ventilated area" is not adequate for a product containing an epoxy resin sensitiser.

Under the COSHH Regulations 2002, you must identify every hazardous substance used on a project, assess the exposure risk, and implement controls that are adequate to reduce that risk. This guide explains the COSHH requirements for the main chemical product categories used in wet area tiling and what your specialist tiling RAMS must say about each of them.

Browse all trade RAMS templates on the RAMS AI trade hub — covering 22 specialist construction trades.

Cementitious Adhesives and Grouts

Cementitious tile adhesives and grouts are the most commonly used products in tiling. They contain portland cement, which is classified as harmful by skin contact (and to a lesser extent by inhalation of dry powder during mixing) due to its strongly alkaline nature.

Key hazards:

• Cement burns (contact dermatitis) — Prolonged or repeated skin contact with wet cement causes alkaline chemical burns. Wet cement in boots is a serious injury risk — knee-length gloves must be worn when working with cement in confined areas or when kneeling in wet adhesive.
• Eye hazard — Cement splashes to the eye are a medical emergency. Safety spectacles must be worn during mixing and application.
• Respiratory hazard during dry mixing — Mixing dry cementitious products generates calcium silicate and cement dust. RPE (FFP2 minimum) should be specified for the mixing operation.

Required controls:

• Waterproof gloves (nitrile or rubber, not latex) during all wet cement handling
• Safety spectacles during mixing and application
• FFP2 RPE during dry mixing operations
• Barrier cream on exposed skin areas
• Washing facilities on site with clean water and pH-neutral soap
• Wet cement on skin must be washed off immediately — do not allow to dry

Epoxy Adhesives and Grouts

Epoxy tile adhesives and grouts are used in high-performance applications — swimming pools, commercial kitchens, chemical-resistant flooring, and anywhere a standard cementitious grout would not provide adequate durability. They consist of a resin component and a hardener (curing agent) that must be mixed before use.

Key hazards:

• Skin sensitisation — Epoxy resin (particularly bisphenol A diglycidyl ether, BADGE) is a Category 1B skin sensitiser. Once sensitised, an operative may be unable to work with any epoxy product without suffering an allergic reaction. This is an occupational disease risk, not just an irritation risk.
• Respiratory sensitisation — Some amine-based hardeners used in epoxy grout systems can cause respiratory sensitisation (occupational asthma) if inhaled during application in poorly ventilated spaces.
• Eye hazard — Epoxy components are severely irritating to the eyes. Eye protection is mandatory.

Required controls:

• Nitrile gloves (minimum 0.2 mm thickness) — latex does not provide adequate protection against epoxy
• Safety spectacles or full-face visor when mixing or applying overhead
• Local exhaust ventilation (LEV) or adequate general ventilation when applying in enclosed spaces
• RPE (A1P2 half-mask) for vapour and particulate exposure during mixing and application in confined areas
• Pre-employment health surveillance for operatives who will regularly use epoxy products
• Immediate removal of any operative who develops sensitisation symptoms

Waterproofing Systems and Tanking Products

Liquid-applied waterproofing membranes and tanking systems used in wet rooms and swimming pools vary in their chemical compositions. Common product types include:

• Cementitious slurry systems — Similar hazard profile to cementitious adhesives. Primary hazards are cement burns and respiratory dust during mixing.
• Polymer-modified bitumen systems — Some pool tanking systems use bitumen-based products. Hazards include sensitising agents and fume exposure during application.
• Reactive resin membranes — Some specialist wet room membranes contain reactive chemical components similar to epoxy resins. Check the SDS for sensitiser content.
• Sheet membrane systems — Hot-applied sheet membranes present burn and fume hazards during torch application.

Your COSHH assessment must be based on the specific product being used — not a generic "waterproofing" assessment. Obtain the Safety Data Sheet for each product from the manufacturer before writing your COSHH assessment.

Silica Dust from Tile Cutting

Cutting porcelain and ceramic tiles generates dust containing respirable crystalline silica (RCS), which causes silicosis — an irreversible and potentially fatal lung disease. The COSHH Regulations set a Workplace Exposure Limit (WEL) for RCS of 0.1 mg/m³ as an 8-hour time-weighted average.

Control hierarchy for tile cutting dust:

• Wet cutting — Wet tile saws using continuous water suppression are the preferred method. Water effectively suppresses silica dust at source. Your RAMS should specify wet cutting as the default method for all porcelain and ceramic tile cutting.
• On-tool extraction — Where dry cutting is necessary (e.g., with an angle grinder for complex cuts), on-tool dust extraction using an M-class or H-class vacuum unit must be used.
• RPE as last resort — If engineering controls alone cannot adequately control exposure, FFP3 disposable masks or P3 filter half-masks must be worn. RPE should be specified as a supplementary measure, not the primary control.

Confined Space and Ventilation Considerations

Wet room and swimming pool tiling frequently takes place in enclosed, poorly ventilated spaces. Your COSHH assessment must address:

• Ventilation adequacy for the products being used (particularly epoxy grouts and any solvent-containing sealants)
• Whether forced ventilation (fans, temporary ventilation units) is required to achieve safe working conditions
• Whether any space qualifies as a confined space under the Confined Spaces Regulations 1997 — typically only deep recesses or tanks, not standard shower rooms
• Maximum continuous working periods in areas of reduced ventilation before breaks are required

What Your COSHH Assessment and Method Statement Must Cover

• List of all chemical products to be used, with SDS reference and COSHH classification
• Exposure route and risk for each product (skin, inhalation, eye)
• Control measures for each product: substitution considered, engineering controls, PPE
• PPE specification: glove type, eye protection, RPE filter rating
• Ventilation requirements during application
• Silica dust controls for tile cutting: wet cutting specification, on-tool extraction details
• Health surveillance requirements for operatives using epoxy products
• Spill and waste disposal procedures for each product category
• Emergency procedures in the event of skin or eye contact

Frequently Asked Questions

Do we need a separate COSHH assessment for each adhesive product or can we use one assessment for all tiling products?

Strictly speaking, you need a separate assessment for each hazardous substance used. In practice, many tiling contractors produce a consolidated COSHH assessment document that covers all products used on a project, with a section for each product. This is acceptable provided each product is assessed individually and the controls are product-specific — a single generic "tiling COSHH assessment" covering all products with the same controls is not adequate.

Is cement burn really a serious risk for experienced tilers?

Yes. Cement burns are a significant occupational health risk for tiling operatives, particularly from prolonged kneeling in wet adhesive or when working with grout in enclosed spaces like shower trays. Experienced tilers can underestimate the risk because the alkali reaction is slow — skin may feel fine during work but develop chemical burns hours later. The HSE registers significant numbers of RIDDOR cement burn incidents in the tiling and laying trades each year.

When do epoxy grout sensitisation risks require health surveillance?

The COSHH Regulations require health surveillance where there is a reasonable likelihood of occupational skin disease or respiratory disease arising from the work. For operatives who regularly use epoxy products, health surveillance (periodic skin and respiratory health checks) is required. The HSE's guidance on COSHH and epoxy resin should be consulted for the specific surveillance frequency. Your COSHH assessment should state the health surveillance requirement and confirm how it is being met.