Repair Systems — 05
Mould & Moisture Damage
Technical product reference for biocide treatment and mould-resistant primer and paint systems for mould remediation and moisture damage repair in Australian Class 2 strata apartment buildings.
What are mould and moisture damage treatment systems?
Mould in Class 2 strata apartment buildings forms when moisture accumulates on internal surfaces — caused by condensation on cold external walls and ceilings, water ingress from above or adjacent units, or inadequate ventilation in bathrooms, laundries and kitchens. Before any biocide treatment or repainting is carried out, the source of moisture must be identified and rectified. Surface treatment of mould without resolving the underlying moisture cause will result in recurrence.
The standard remediation sequence for mould-affected internal surfaces is: apply biocide wash to kill active mould spores and break down the mould colony at the surface, allow the surface to dry thoroughly, apply a suitable primer, then apply a mould-resistant topcoat. Skipping the biocide wash step and painting directly over mould contamination is a common defect in mould remediation works — the mould colony must be killed and removed before any paint system is applied.
Mould-resistant interior paints contain an active inhibitor in the paint film that suppresses mould re-growth on the surface in high-humidity environments. These paints are appropriate for bathrooms, laundries, kitchens and other mould-prone areas, and are significantly more effective than standard interior paints in high-humidity conditions. However, the active inhibitor reduces over time and is not a substitute for resolving the moisture source — standard paint in a continuously damp environment will always fail regardless of mould-resistant additives.
Do not confuse with:
- Mould-resistant grout — tile grout system for joints between tiles, not a paint or surface coating for walls and ceilings
- Waterproofing membranes — membrane systems to prevent water ingress, not a mould treatment or surface paint
- Exterior facade biocide — exterior cleaning and biocide products formulated for facade use, not internal walls and ceilings
Product Reference
2 products — 2 brands — mould and moisture damage treatment systems — scroll to view all
System Description
Selleys Rapid Mould Killer is a ready-to-use biocide spray for removing mould, mildew and algae from internal walls and ceilings prior to repainting. Applied directly from the trigger spray bottle to affected surfaces, allowed to dwell and rinsed or wiped off. Kills active mould spores at the surface, preparing the substrate for primer and topcoat application. The source of moisture causing mould growth must be identified and rectified before applying any biocide treatment — surface washing does not address underlying water ingress, condensation or plumbing leaks. Confirm current dwell time and application instructions with the current Selleys product label before use.
Technical Properties
- Ready-to-use biocide spray — no dilution required — fast acting, spray and rinse application
- Kills mould, mildew and algae spores at the surface — prepares substrate for repainting
- Trigger spray bottle — suitable for internal use with adequate ventilation
Limitations
- Surface treatment only — does not address the source of moisture — moisture source must be rectified before treatment
- Deeply penetrated mould in plasterboard (greater than 3mm) requires full plasterboard replacement — surface washing is not sufficient
- PPE required — respiratory protection, gloves and eye protection mandatory during application
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
Dulux Wash&Wear +PLUS Kitchen&Bathroom Low Sheen
Premium interior paint with active mould inhibitor
System Description
TODO: owner confirm — Dulux Weathershield is an exterior product range and is not suitable for interior use. The current Dulux interior mould-resistant paint for bathrooms, kitchens and laundries appears to be Dulux Wash&Wear +PLUS Kitchen&Bathroom Low Sheen, which features Mouldshield Technology and a 10-year guarantee against mould growth on the film. Confirm the correct product name and formulation with Dulux Australia before specifying — product names are subject to periodic revision. Apply over a suitable primer following biocide washing and surface preparation. The active inhibitor in the paint film does not compensate for ongoing moisture — the source of moisture must be rectified before repainting.
Technical Properties
- Built-in active mould inhibitor — suppresses mould re-growth on the paint film in high-humidity environments
- Water-based formulation — low VOC — suitable for internal use with standard ventilation
- Premium interior paint — washable, durable film — suitable for ceilings and walls
Limitations
- Active inhibitor in the paint film does not address the source of moisture — water ingress or condensation must be resolved before repainting
- Not suitable as a standalone waterproofing system — mould-resistant paint is a surface coating only
- Mould resistance of the film will reduce over time — regular cleaning and maintenance required in high-humidity areas
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
System Comparison
Side-by-side technical comparison of mould and moisture damage treatment products. Confirm current product specifications with manufacturer TDS.
| Product | Brand | Type | Mould kill | Paintable | Substrate | Primary use |
|---|---|---|---|---|---|---|
| Selleys Rapid Mould Killer | Selleys | Biocide spray | Yes — kills active spores | N/A — preparation product | Plasterboard, paint, masonry | Pre-paint biocide spray — mould removal from walls and ceilings |
| Dulux Wash&Wear +PLUS Kitchen&Bathroom (TODO: confirm name) | Dulux | Interior paint | Inhibits re-growth on film (Mouldshield Technology) | Yes — is the topcoat | Primed plasterboard, masonry | Mould-resistant topcoat for bathrooms, kitchens, laundries |
Brand Equivalents
Mould treatment product equivalents across brands active in Australian Class 2 strata remediation.
| System type | Selleys | Dulux |
|---|---|---|
| Biocide spray (mould removal) | Rapid Mould Killer | — |
| Mould-resistant interior paint | — | Wash&Wear +PLUS Kitchen&Bathroom (TODO: confirm) |
Source identification is mandatory before treatment
- Mould recurs if the moisture source is not rectified — water ingress, condensation or plumbing leak must be resolved first
- Widespread mould on plasterboard (penetrated more than 3mm) requires full plasterboard replacement — surface washing alone is not sufficient for deeply contaminated board
- PPE required during mould washing — respiratory protection, gloves and eye protection for any remediation involving significant mould growth
Disclaimer
Information is general only. The source of moisture must be identified and rectified before mould treatment — biocide washing and repainting does not address underlying dampness or water ingress. Product selection must be confirmed against substrate and the current manufacturer technical data sheet. For significant mould infestations, engage a mould remediation specialist. Do not rely on this reference as a substitute for professional advice.