Use Duram S900 for: Weatherproofing porous masonry; minimising efflorescence; assisting with mould/fungal resistance; protecting from rain and salt spray while keeping the original look.

Duram S900: A Technical Overview

Duram S900 is a clear, deep-penetrating siloxane solution formulated for high-pH mineral substrates. It soaks into porous surfaces to create a weatherproof barrier below the surface, maintaining vapour diffusion so substrates can breathe. Ideal for external concrete, cement render, face brick and porous pavers, S900 helps reduce efflorescence and biological growth, and supports the long-term integrity of masonry exposed to rain and salt spray. Application is by saturation in wet-on-wet coats to ensure sufficient uptake in the pore structure, drying to a non-gloss clear finish.

Core Features & Specifications

  • Deep penetrating siloxane chemistry – forms a sub-surface weatherproof barrier without altering appearance.
  • Breathable system – allows vapour diffusion to reduce trapped moisture risk.
  • High pH tolerant – suitable for new concrete and lime-based mortars/bricks.
  • Clear, non-gloss finish – maintains original aesthetic of masonry.
  • Quick drying – touch dry ~2–4 h; full cure typically 12–24 h at 25°C/50% RH.
  • Packaging: 15 L pail; Colour: Clear; Shelf life: 12 months (unopened, stored correctly).

The Duram S900 Advantage

  • Weatherproof barrier that preserves the original look—no film build or sheen.
  • Supports longer-term substrate durability by limiting water ingress.
  • Efficient application—brush, roller, spray or pour; repeat wet-on-wet to target porosity.
  • Versatile across common porous mineral substrates including terracotta and sandstone.

Proactive Troubleshooting

Scenario: Under-saturation on highly porous or friable areas

Potential Outcome: Insufficient pore filing can leave pathways for water ingress, reducing weatherproofing performance.

Best Practice: Apply multiple wet-on-wet soaking coats until refusal, prioritising highly porous zones. Always test a small area to confirm uptake and finish before proceeding.

Scenario: Applying over damp or contaminated surfaces

Potential Outcome: Uneven penetration and possible discolouration or reduced effectiveness.

Best Practice: Ensure surfaces are dry, sound and clean. Remove laitance/efflorescence by wire brushing, wash and allow to dry prior to application.

Applications in Practice: Trade Scenarios

For Waterproofers (On-site Applicator): Balcony screeds & masonry facades

The Professional's Challenge

Wind-driven rain and salt spray drive moisture into porous balcony screeds and façade brickwork, risking efflorescence and staining without changing the façade’s look.

The Adheseal Solution

Saturate the surface using wet-on-wet coats until refusal so S900 penetrates deeply. Maintain a consistent, even soak. Typical working temperature: 5–30°C; allow full cure 12–24 h before service.

Best Practice Note

Focus on edges, parapets and drip lines where porosity is highest; these areas often require extra passes to achieve uniform uptake.

For Builders (Business Owner/Operator): Sandstone and porous paver hardscapes

The Professional's Challenge

Delivering long-lasting, low-maintenance hardscape finishes without altering the natural stone appearance.

The Adheseal Solution

Apply S900 by low-pressure spray or roller and immediately follow with additional wet-on-wet coats. Target coverage varies with porosity—expect lower m²/L on highly porous stone.

Best Practice Note

Always conduct a test area to confirm appearance on decorative stone and verify the number of soaking coats required.

For Tilers (On-site Applicator): Terracotta & grout lines

The Professional's Challenge

Terracotta and grout are highly porous and prone to rapid water uptake and efflorescence at joints.

The Adheseal Solution

Concentrate application along grout lines and terracotta faces using repeated wet-on-wet soaking passes until refusal. Allow 12–24 h cure before service.

Best Practice Note

Mask adjacent non-porous finishes and maintain ventilation throughout application and curing.