In the world of sustainable construction, water-based hydrophobic treatments are increasingly becoming the standard. These modern technologies offer powerful, long-lasting protection for facades and roofs. They combine technical performance with environmental responsibility, are safe to use, and perfectly suited for sensitive projects such as schools, homes, or hospitals. For contractors, painters, and renovation professionals, they are the ideal solution for permanently repelling moisture, pollution, and frost damage – with respect for people and the environment.
Hydrophobics are specialized impregnating agents that protect mineral building materials such as concrete, brick, plaster, or natural stone from water ingress and contamination. The active ingredients in hydrophobics typically belong to the chemical families of silanes, siloxanes, silicones, or other functional polymers. Depending on the product type, these components are either dissolved in organic solvents (solvent-based hydrophobics) or emulsified/dissolved in water (water-based hydrophobics).
When applied to a porous substrate, the hydrophobic agent penetrates deep into the capillary networks and microstructures of the material. Once inside, the active substances chemically react with the mineral components of the substrate. This process – usually via hydrolysis followed by polymerization – forms a hydrophobic, water-repellent zone within the surface, without forming a film on the exterior.
Advantages of Water-Based Hydrophobics
Full Compliance with VOC and Environmental Legislation
Water-based hydrophobics offer a solution to the increasingly strict environmental regulations in the construction sector. VOC use (volatile organic compounds) is heavily regulated by European and national legislation due to their impact on public health and air quality. Modern water-based products are completely solvent-free, non-flammable, and odorless. This makes them especially suitable for urban environments and sensitive areas such as schools, hospitals, healthcare facilities, and residential buildings.
Extended Service Life and Structural Protection
A high-quality hydrophobic treatment provides long-term protection for mineral substrates – such as brick, plaster, and concrete – against moisture ingress, pollution, and freeze-thaw cycles. This not only significantly extends the life of the material but also reduces the need for frequent maintenance or renovation. In doing so, a durable hydrophobic agent contributes to lower material consumption, reduced waste generation, and decreased CO₂ emissions throughout the building’s life cycle. This is a key factor in meeting sustainability labels and environmental performance standards in modern construction projects.
Compatibility with Ecological and Bio-Based Building Materials
Another major benefit of water-based hydrophobics is their excellent compatibility with natural and circular building materials such as lime plasters, clay plasters, lime screeds, and other bio-based products. Since these substrates are often highly porous and alkaline, it is essential that a hydrophobic agent can penetrate deeply without forming a surface-sealing film. Water-based formulations perform excellently here: they remain vapor-open, allow the material to breathe, and offer effective water repellency without compromising the aesthetics or functionality of the substrate. They fit perfectly within the principles of circular construction and renewable material flows.
Thinking Ahead in a Changing Construction Landscape
Sustainable and healthy building is no longer a niche – it’s becoming the norm. Developers, architects, and contractors increasingly face EPB requirements, environmental certifications, and client expectations related to ecology and health. Water-based hydrophobics meet this new reality: they are easy to use and compatible with both modern construction methods and renovation practices. By choosing water-based alternatives, you position yourself as a forward-thinking professional focused on quality and sustainability.
Water-Based Hydrophobics for Facade and Roof
RC HYDROCREME 4 – Cream-Based Hydrophobic with Maximum Penetration
RC HYDROCREME 4 is an advanced cream-type hydrophobic agent specially developed for long-term protection of highly porous mineral substrates such as brickwork, natural stone, and concrete. With a high active content of 25%, this concentrated formula delivers deep-penetrating, water-repellent performance. The cream adheres excellently to vertical surfaces and creates a pronounced beading effect without blocking vapor permeability. Thanks to its high alkali resistance (up to pH 14), RC HYDROCREME 4 is also ideal for fresh substrates such as new plasters or cement-based materials. Not suitable for dense or non-porous surfaces.
RC 805 ECO – Solvent-Free Facade Protection with Long-Term Effectiveness
RC 805 ECO is an innovative, water-based hydrophobic treatment completely free of solvents and VOCs (volatile organic compounds). The formulation is based on a combination of high-performance polymers such as silanes, siloxanes, fluorinated resins, and polyolefins. This blend ensures deep penetration into mineral building materials such as concrete, brick, and natural stone (excluding bluestone), even on alkaline surfaces. RC 805 ECO does not form a film on the surface, allowing the substrate to remain breathable and maintain its natural vapor exchange.
RC HYDROTOP – Effective Roof Impregnation for Long-Term Protection
Developed specifically for the demands of roof surfaces, RC HYDROTOP is a water-based impregnation product based on a silane/siloxane emulsion. It creates a hydrophobic barrier in roof tiles, concrete tiles, and ceramic shingles, without forming a visible film or altering the surface color. RC HYDROTOP's vapor-open structure allows the roof to breathe, while significantly reducing moisture ingress and the growth of moss, algae, and fungi. This keeps the roof not only technically protected but also clean and well-maintained, even under prolonged exposure to rain and environmental pollution.
With RC HYDROCREME 4, RC 805 ECO, and RC HYDROTOP, Reynchemie offers a range of specialized hydrophobics tailored to specific applications – from facade to roof. Each product combines top-level technical performance with ecological responsibility. Thanks to their water-based formulation, safety in use, and long lifespan, these solutions are perfectly suited for professionals committed to building, renovating, or protecting sustainably – without compromising on quality or environmental standards. Choose water-based technology that anticipates the challenges of today and tomorrow.
