OPTOLITH Optosan HydroSilan –

Clear Hydrophobic Impregnation for Mineral Surfaces

OPTOLITH Optosan HydroSilan is a high-quality, ready-to-use, solvent-free impregnating agent based on silanes and siloxanes, designed for hydrophobizing absorbent mineral building substrates. The product deeply penetrates the material structure, forming a long-lasting moisture barrier that effectively prevents rainwater penetration while maintaining the surface's vapor permeability. It is ideal for protecting façades made of brick, concrete, mineral plasters, and sandstone from moisture, efflorescence, and contaminants.

Applications:

• Hydrophobic impregnation of façades made of mineral plasters, brick, architectural concrete, silicate blocks, sandstone, and other absorbent mineral materials

• Protection against water, salts, and dirt penetration

• For exterior use – especially recommended for the renovation and preservation of historic buildings

Key Features and Benefits:

• Effective protection against rainwater – significantly reduces surface absorbency, protecting the material from degradation

• Maintains vapor permeability – allows the wall to "breathe," preventing moisture buildup within the structure

• Clear impregnation – does not alter surface appearance, ideal for historic and decorative façades

• Long-lasting hydrophobic effect – resistant to weather conditions, UV radiation, and salt exposure

• Easy application – ready to use, applied by low-pressure spray (recommended) or roller

Technical Data:

• Consistency: liquid

• Color: clear when dry

• Consumption: approx. 0.2–0.5 l/m² (depending on substrate absorbency)

• Application temperature: from +5°C to +30°C

• Absorption time: up to 30 minutes

• Packaging: 5 L, 10 L, and 30 L (availability depends on distributor’s offer)

Application Guidelines:

Before application, the substrate must be dry, clean, stable, and free from efflorescence, contaminants, dust, oils, moss, and lichen. Apply using a low-pressure spray (recommended) or roller, in one or two “wet-on-wet” layers until the surface is fully saturated. Do not apply to painted surfaces or unglazed ceramics. Full hydrophobic performance develops approx. 24–48 hours after application.

Technical Data Sheet