Efflorescence with algae in damp conditions

Basement walls, retaining walls, or ground-floor exterior where white salt crystals appear alongside green or black biological growth due to persistent moisture

Why order matters

When two problems appear together, the treatment order is critical. Using the wrong product first can spread stains, neutralise chemicals, or cause new damage. Follow these steps in order.

Treatment Steps

1. Step 1: Efflorescence

   Product: Lithofin MN Builders' Clean (diluted) + moisture investigation

   Why this order: Address the moisture problem first. Efflorescence signals active water movement through the stone - this same moisture feeds the algae. Dry-brush salt crystals, then investigate moisture source.

   Method: Dry-brush loose salt crystals with stiff brush. Apply diluted Builders' Clean (1:10) to remaining deposits. Rinse. Investigate and address moisture source (drainage, waterproofing, ventilation).

   Wait: Address moisture problem. Wait for surface to dry (may take weeks for wall cores to dry)

2. Step 2: Algae Moss

   Product: Lithofin ALGEX

   Why this order: Once moisture is reduced, treat algae. Without addressing moisture first, algae will return within weeks.

   Method: Apply ALGEX to all affected areas. Leave 24 hours. Remove with brush and rinse. Improve ventilation and drainage to prevent recurrence.

   Wait: Monitor for 4-6 weeks. If efflorescence returns, moisture source is not resolved.

Warnings

• This combination always indicates a moisture problem - chemical treatment alone will not solve it permanently
• Do not seal the surface while moisture is still active - trapped moisture worsens both problems
• Consider professional moisture assessment for structural walls