Efflorescence is a common issue affecting masonry surfaces, particularly permeable materials such as concrete, brick, and stone. It appears as a white, powdery or crystalline residue on the surface. This occurs when moisture within the masonry dissolves salts and transports them to the surface. As the moisture evaporates, the salts remain behind, creating the characteristic white staining. While efflorescence is not structurally harmful, it is unsightly and often indicates ongoing moisture movement.
Efflorescence removal can be achieved using a range of specialised cleaning products available on the market. However, in many cases, effective cleaning can be done with common household materials.
For mild efflorescence, household vinegar is often sufficient. For more stubborn deposits, diluted hydrochloric acid or phosphoric acid may be required. When using any acid‑based cleaner, proper dilution with clean water is essential.
The most effective way to prevent efflorescence is to keep moisture out of the masonry. Applying a high‑quality penetrating silicone sealer helps repel water while allowing the surface to remain breathable. This prevents moisture from carrying salts to the surface.
Penetrating sealers are especially valuable around pools, decks, driveways, and alfresco areas, where moisture exposure is high. Premium sealers can also repel oil, making them ideal for barbecue areas and outdoor entertaining spaces.
In addition to sealing, good building maintenance is essential. Addressing leaking downpipes, faulty gutters, poor drainage, and other moisture sources will significantly reduce the likelihood of efflorescence returning.