Quick answer: Surface prep is 70% of a successful waterproofing job. Strip back loose paint, high-pressure clean, repair cracks with a flexible filler, prime with Rhinoluxe Bond and Key, then apply Rhinoluxe Shield Exterior in two full coats. Skipping prep is the most common reason exterior waterproofing fails inside a year.
Why prep matters more than the topcoat
Even the best waterproof paint only bonds as well as the surface underneath it. A chalking, dusty or hairline-cracked wall will release the paint film within 6–18 months no matter how good the topcoat. The Rhinoluxe Shield system is designed for proper SABS-grade prep — under-prepped walls don't get the warranty bracket.
Step-by-step prep
- Inspect the wall. Look for hairline cracks, blistering, chalking, mould, peeling paint, salt deposits.
- Strip loose material. Scrape off blistered or peeling paint until you hit sound substrate. Wire-brush rust spots on any metalwork (gates, railings touching the wall).
- High-pressure wash. 1200–1800 psi on plaster, lower (800 psi) on older or fragile walls. Remove dust, salt, algae, lichen.
- Mould treatment. If you see mould or algae, treat with a fungicidal wash or dilute bleach (1:4). Let dry fully.
- Crack repair. Hairline cracks (<1mm): can be bridged by Shield Exterior alone. Larger cracks: cut out, fill with a flexible exterior filler, sand flush.
- Spot-prime patches. Where you've filled or where the original substrate is now exposed.
- Allow to dry. Walls must be touch-dry and weather-dry. After rain, give at least 48 hours of dry weather.
Choosing the right primer
| Surface condition | Recommended primer |
|---|---|
| Chalking paint / shiny old paint | Rhinoluxe Bond and Key (universal adhesion) |
| New plaster / cement render | Plaster primer (alkali-resistant) |
| Exposed brick | Bond and Key |
| Rusted metal sections | Rhinoluxe ZP4 Primer (zinc phosphate) |
Applying Shield Exterior
Apply two full coats of Rhinoluxe Shield Exterior by brush, roller or airless spray. Allow 4–6 hours between coats. Don't apply if rain is forecast within 24 hours or if surface temperature is below 10°C or above 35°C.
Common mistakes
- Painting over chalking paint without Bond and Key — film releases inside 6 months.
- Skipping the mould wash — mould grows back under the new film.
- Applying one thick coat instead of two thinner ones — DFT looks the same but the film stays soft.
- Waterproofing only the cracked areas — leaves edges that delaminate.
- Working in direct hot sun on dark walls — Shield Exterior skins over too quickly, trapping solvent.
Where to buy
Order Rhinoluxe waterproofing paints at rhinoluxe.co.za with national delivery, or visit our paint shops at 143 Blaauwberg Road, Table View, Cape Town or 5a Betschana Road, Sebenza, Edenvale, Johannesburg. For trade pricing on bulk orders, call +27 84 985 6141.
