- Concrete.
- Cement.
- Asbestos.
1. Remove Loose Material & Clean Thoroughly
- Use a stiff scraper or high-pressure water jet to remove all loose or flaking material—this includes old paint, debris, mould, or algae.
- For mould or algae, treat the surface with Multilac Disinfecting Wall Wash, applying with appropriate protective gear. Allow it to work for 24–48 hours, then wash and scrub using high-pressure water to remove bleach residue and dead growth.
2. Repair Leaks & Stains
- Fix any active leaks or drips that could cause staining.
- Allow the surface to fully dry out. If stains reappear, apply two coats of Multilac Supreme Life Water Proofing Sealer (solvent-based) to seal through and let it dry for 24–48 hours