Innovative, hydrophobic acrylic coatings and finishes enhance an exterior wall’s weather resistance and more effectively repel water than traditional paints and coatings by mimicking the waterproofing properties of lotus flowers – by providing the ultimate solution for water damage prevention.
In addition, hydrophobic acrylic coatings and finishes contribute towards ensuring all layers of the building envelope (including the finished surface layer) work to control moisture infiltration and accumulation, which is vital to meeting the demands of today’s building owners and code requirements for healthy, sustainable, and resilient structures.
How to Measure the Hydrophobicity of a Coating or Finish
Manufacturers measure hydrophobicity by setting a water droplet on the product’s surface and watching the angle as the droplet moves – the contact angle. Manufacturers define coatings with a contact angle of 90 degrees or greater as hydrophobic, while coatings with 150 degree or greater contact angles are super-hydrophobic.
Super-hydrophobicity allows more water to roll off the wall, which prompts faster drying and removal of dirt. In addition, super-hydrophobicity protects a building’s exterior and long-term value by resisting mold, water, dirt, staining, extreme temperatures, and UV rays.
The Lotus Effect – Super Hydrophobic
A 7000 magnified lotus leaf microstructure.
StoColor® Lotusan® Mimics the Lotus Leaf
Smooth, super-hydrophobic StoColor® Lotusan® is an above-grade, vertical exterior wall coating with Lotus-Effect® Technology. Builders can use it on stucco, masonry, EIFS, concrete and previously painted wall surfaces.
The Science Behind StoColor® Lotusan®
Tiny wax pillars (smaller than 100 microns apart) coat the lotus plant’s leaves, which helps to waterproof and clean the plant. The high surface tension of water does not allow it to infiltrate through the pillars and into the leaf, which creates a hydrophobic effect that forces moisture to bead and roll off the leaf. The beads pick up dirt particles as they roll off the leaf, which keeps the lotus leaves clean and dry — the lotus effect.
TowerHouse Condominium in Miami Beach, Florida
The condo association chose StoColor® Lotusan® coating to paint this 50-year-old structure because of the coating’s longevity, waterproofing capacities, and self-cleaning Lotus-Effect® Technology.
Problems with Conventional Exterior Wall Coatings
Conventional exterior coatings lack resistance against many outdoor elements (bulk water, temperature, UV exposure, impact, pollution, and biological organisms), which affects the structure’s integrity and the occupant’s safety and comfort:
- Bulk Water: Rain, dew, snow, humidity, etc., can cause a conventional water-based coating to soften and become sticky, which further attracts dirt.
- Temperature and UV exposure: Hot temperatures and sun rays can degrade coatings on the building’s exterior, which leads to fading after years of exposure.
- Impact: Flying debris, hail, building movement, equipment, etc., can all cause abrasions and compromise exterior cladding paint and coatings.
- Pollution: Nitrogen oxides, smoke, dust, soot, fertilizers, nitrates, etc., can all damage a facade’s coatings.
- Biological Organisms: Fungi and mildew create an unattractive green appearance that can diminish the coating’s effectiveness. In humid climates, fungal growth tightly bonds and leaves a coating on the coating’s surface.
Hydrophobic Coatings and Finishes Repel Water
Hydrophobic coatings and finishes repel water, which helps resist mold, algae, and mildew and reduces maintenance costs by increasing the time between recoats.
Stolit® HDP® Hydrophobic Finish
Builders can use ready-mixed Stolit® HDP® as an exterior and interior decorative textured wall finished (fine, medium, swirl, and freeform textures) on Sto wall systems and over-prepared vertical above-grade masonry, concrete, and stucco substrates.
Stolit® HDP® provides several other significant benefits and features, including:
- Excellent water repellency, which helps maintain clean walls
- The high water vapor permeability allows a substrate to breathe naturally, which provides superior resistance to blistering and peeling.
Integral Colorants create lasting, uniform color - Enhanced Polymer Technology spreads and floats easily and provides UV resistance.
- Water-based, and is safe, non-toxic, and cleans up with water
- Low VOC improves a building’s IAQ and protects the environment
Super-Hydrophobic Coatings – The Ultimate Solution for Water Resistance and Moisture Damage Prevention
Super-hydrophobic microstructure coatings repel water by rolling it off the surface, in order to limit an exterior wall’s contact with dirt and water. This process mimics the lotus leaf’s water-repellent surface and self-cleaning abilities.
The Advantages of Super-Hydrophobic Coatings
Super-hydrophobic acrylic coatings for recoating existing buildings and new construction repel water and dry quickly. The process lessens the opportunity for mildew, mold, dirt, and other pollutants to grow or stick on the surface.
Super-hydrophobic coatings also help maintain the building’s exterior aesthetic and benefit the building owners by enhancing the wall’s integrity, lessening costs, and reducing maintenance:
Long-Term Integrity and Appearance Advantages
Hydrophobic coatings resist weather, algae, mold, mildew, and UV, which enhances the exterior wall’s long-term integrity and appearance.
Lessens Long-Term Costs
Hydrophobic coatings create durable exteriors, which can eliminate annual pressure washing and allow for longer periods between recoating, lessening the total cost of ownership. Over two decades, hydrophobic coatings may save nearly 80 percent of the total expense of a standard coating product.
Reduces Maintenance
Hydrophobic coating’s water-shedding properties ensure rapid drying and dirt removal and produce coatings that last up to ten years – conventional coatings only last two to three years. Therefore, hydrophobic coatings have lower long-term maintenance costs.
Hydrophobic acrylic coatings also often include silicone polymer technology, which provides longer fade resistance durability than conventional acrylic coatings.
Super-Hydrophobic StoColor® Lotusan® Coating
Highly water-repellent StoColor® Lotusan® surface coating with LotusEffect® Technology keeps buildings’ facades clean and attractive while also saving money on maintenance and recoating. In addition, easy and seamless to apply StoColor® Lotusan® comes in numerous colors within the StoColor® offerings.
StoColor® Lotusan® provides three significant features: super-hydrophobic, vapor permeability, and UV resistance:
1. Super-hydrophobicity provides:
- Enhanced resistance to mold, mildew, and algae
- Superior water repellency
- Excellent dirt resistance
2. Vapor permeability allows the substrate to breathe naturally to resist blisters caused by trapped water vapor.
3. UV resistance ensures a facade with superior color retention.
Self-Cleaning StoColor® Lotusan®
StoColor® Lotusan® is a superior coating solution for new construction and recoat projects over stucco, concrete, EIFS, fiber cement board, and pre-painted or primed wood substrates. The self-cleaning component of super-hydrophobic StoColor® Lotusan® effectively protects the exterior facade with the following features:
- Excellent weather and chalk resistance
- UV-stable
- High water vapor permeability
- Resists the growth of algae, mold, and mildew
- Smooth matte (flat) surface
- High level of water- and dirt-repellent after the coating dries
Protect Exterior Walls from Water Damage with StoColor Lotusan Super-Hydrophobic Coating and Stolit HDP Hydrophobic Textured Finish
Hydrophobic Stolit HDP textured finish and super-hydrophobic StoColor® Lotusan® coating will both repel water, which helps keep a wall attractive while also saving money on recoating and maintenance.
Super-hydrophobic StoColor® Lotusan® exterior coating (Lotus-Effect® Technology), however, allows dirt and rain to flow off the coating surface like rain droplets falling off a lotus leaf, which helps protect the facade from water damage and keeps it attractive while also saving money on recoating and maintenance.
Contact the Sto professionals today at (800) 221-2397 today for more information on how hydrophobic coatings and finishes for exterior wall systems can prevent water damage!
