Protect Your Laterite Brick Wall: Natural & Durable Wall Coating Step by Step Guide

Laterite stone or brick, with its distinctive earthy hues and porous texture, has been a cornerstone of construction in many regions, particularly for its natural availability, excellent thermal insulation properties, and unique aesthetic appeal.

Did You Know?

Laterite brick construction is notably common in specific regions of India, primarily due to the natural availability of laterite soil and the stone’s suitability for the local climate. The major areas include:

Coastal Karnataka: Regions like Dakshina Kannada, Udupi, and Uttara Kannada have a strong tradition of using laterite in residential buildings, temples, and other structures. The stone’s porosity helps in maintaining cooler interiors in the humid climate.
Kerala: Laterite is extensively used throughout Kerala, especially in the coastal and midland regions. Its use ranges from foundation work to wall construction in houses, churches, and historical monuments. The term ‘laterite’ itself was first coined in the Malabar region of Kerala.
Goa: Laterite is the most significant traditional building material in Goa. A large part of Goa is covered with laterite plateaus, making it readily available. It’s used in almost every type of construction, from simple houses to elaborate churches, forts, and temples, showcasing its durability over centuries in the coastal climate.
Maharashtra (Konkan region): The coastal belt of Maharashtra, known as Konkan, also sees widespread use of laterite in construction, similar to the neighboring regions of Goa and Karnataka. Forts and old houses in this area often feature laterite masonry.
Parts of Tamil Nadu: Some districts of Tamil Nadu, particularly those bordering Kerala and Karnataka, also utilize laterite for construction, especially in rural areas.
Hilly areas of Assam: Laterite soils are found in the hilly regions of Assam, and the stone is used to some extent in local construction.
Andhra Pradesh: Some southern districts of Andhra Pradesh also show the use of laterite bricks in housing and other structures.

These regions have historically relied on laterite due to its local abundance, ease of cutting when freshly quarried, and its hardening properties upon exposure to air, making it a durable and cost-effective building material for the local climate. The unique reddish-brown hue of laterite also contributes to the distinctive architectural character of these areas.

Protection of Laterite Stones

From rustic homes to grand architectural marvels, laterite bricks lend a character and charm that few other materials can replicate. However, its inherent porosity also makes it susceptible to water absorption, leading to issues like dampness, efflorescence, and eventual structural degradation.

Protecting laterite walls is crucial not only for their longevity but also for preserving their natural beauty. Fortunately, advanced technologies offer effective solutions without compromising the stone’s inherent charm. This article delves into two distinct yet highly effective systems for protecting your laterite stone walls: Organo Silane Chemistry and Clear Acrylic Chemistry. We will provide a detailed, step-by-step guide for each, empowering homeowners, architects, and builders to make informed decisions and ensure the enduring beauty and integrity of their laterite structures.

Understanding the Need for Protection

Before we delve into the application processes, it’s essential to understand why laterite stone needs protection. Like we mentioned above, it’s porous nature allows water to penetrate easily. This absorbed water can lead to several problems:

Dampness in Interiors: Moisture seeping through the walls can cause damp patches, mold growth, and an unhealthy indoor environment.
Efflorescence: Dissolved salts within the stone can be carried to the surface by water and deposited as unsightly white powdery stains.
Structural Weakening: Continuous water ingress can weaken the mortar joints and even the stone itself over time, leading to cracks and structural instability.
Discoloration and Degradation: Exposure to the elements can cause the natural colour of laterite to fade or become stained, diminishing its aesthetic appeal.

We continue to receive calls from renowned architects from Goa, Mumbai etc who face this dampness issue in the interiors of their marvellous creations. Therefore we thought of publishing a detailed article on implementing a suitable protection system as a proactive measure to safeguard your investment and maintain the natural beauty of your laterite walls for years to come.

Protecting Laterite Stone Walls with Organo Silane Chemistry

Organo Silane is based on advanced nano technology based organo silane chemistry. It works by penetrating deep into the porous structure of the laterite stone and reacting chemically to create a hydrophobic (water-repellent) barrier within the material itself, without forming a visible surface film. This approach preserves the natural look and breathability of the stone while providing excellent water resistance.

Surface Preparation for Organo Silane Application
Proper surface preparation is important for the successful application and long-term performance.

Cleaning the Surface: Begin by thoroughly cleaning the laterite walls to remove any dust, dirt, loose mortar, biological growth (like algae or moss), and other contaminants. Remember to clean to your satisfaction as after the treatment, the look will be all the same including any missed out spots/marks.

Method: Use a stiff brush or broom for loose debris. For stubborn dirt and biological growth, you can use a mild detergent solution followed by a thorough rinse with clean water. A pressure washer can be used with caution, ensuring the pressure is not too high to damage the stone or mortar joints. Allow the wall to dry completely for at least 24-48 hours, depending on the weather conditions. The surface must be dry to the touch and free from any visible moisture before proceeding.
Tools/Materials: Stiff brush, broom, mild detergent, clean water, pressure washer (optional).

Plugging Cavities (Very Important and you will thank us later): Laterite stones often have natural cavities and pores. These can act as pathways for water ingress, potentially leading to dampness inside. It’s crucial to identify and seal these effectively.

Method: Carefully inspect the entire wall surface for any visible cracks, holes, or deep pores. For smaller cavities and cracks (up to 5-10 mm), a white cement-based grout or a specialized stone filler can be used as detailed ahead. For larger cavities, you might need to use small pieces of matching laterite stone held in place with specialized stone filler. To achieve a natural look, try to match the colour of the filler or mortar as closely as possible to the surrounding laterite. You can achieve this by mixing terracotta tile joint grout along with laterite stone powder into the white cement along with polymer. (White Cement: Laterite powder: Terracotta colour tile joint grout – (1: 0.5:0.25) and add adequate quantity of SBR or acrylic co-polymer liquid for wetting to form a paste consistency. Ensure the filler is pressed firmly into the cavity and levelled with the surrounding surface. Allow the repair work to cure completely according to the manufacturer’s instructions (typically 24-72 hours).
Tools/Materials: Trowel, pointing trowel, cement, fine sand, water, pigments (to match laterite colour as mentioned above), stone filler (optional), small pieces of laterite stone (for larger cavities).

Application Procedure for Organo Silane

Applying Organo Silane is a straightforward process, but attention to detail is key.

Dilution: Organo Silane is typically supplied in a concentrated form and needs to be diluted with clean water before application.

Ratio: Follow the manufacturer’s instructions for the recommended dilution ratio. A common ratio is often between 1:10 to 1:40 (Organo Silane : Water), but always refer to the specific product information for guidelines based on the porosity of the laterite.

Application Method: Organo Silane can be applied using various methods:

Spraying: A low-pressure garden sprayer or an airless sprayer is often the most efficient method for larger areas, ensuring even coverage. Apply in a consistent, overlapping manner, working from top to bottom.
Brushing: For smaller areas or intricate details, a wide, soft brush can be used. Ensure thorough saturation of the surface.
Rolling: A low-nap roller can also be used for larger, relatively even surfaces.

Number of Coats: Typically, a single, thorough spray of Organo Silane is sufficient as it penetrates deeply into the substrate. Saturation of the surface is the key. However, for highly porous laterite or areas exposed to severe weather, a second spray might be recommended after the first spray has been absorbed but is still slightly damp (wet-on-wet application). Always follow the manufacturer’s recommendations.

Drying Time: Organo Silane does not form a surface film, so there is no traditional “drying time” in the sense of paint. The product is absorbed into the stone. However, allow the treated surface to remain undisturbed for at least 4-6 hours after application to allow for proper penetration and reaction. Avoid any rain or water contact during this period. Full hydrophobic effect will typically develop within 24-72 hours.

Safety Precautions:

Wear appropriate personal protective equipment (PPE) such as gloves, eye protection, and a mask, especially when spraying.
Ensure adequate ventilation in the work area.
Keep the product away from children and pets.
Refer to the Safety Data Sheet (MSDS) for detailed safety information.

Maintenance Tips for Organo Silane -Treated Walls

Laterite walls treated with Organo Silane require minimal maintenance to retain their water-repellent properties and natural appearance.

Regular Cleaning: Occasional cleaning to remove surface dust and dirt is recommended.

Method: Use a soft brush or gently rinse with clean water. Avoid using harsh chemicals or abrasive cleaners, as these can potentially affect the treated surface over time, although Organo Silane is generally resistant to mild cleaning agents.

Inspection: Periodically inspect the walls for any signs of damage or new cracks. Address any structural issues promptly to prevent water ingress through damaged areas.

Reapplication: Organo Silane provides long-lasting protection, typically for several years (5-10 years or more), depending on the exposure conditions and the porosity of the stone. Reapplication may be necessary when you notice a reduction in the water-repellent effect (water no longer beads up on the surface or stone shows water wetting signs). Follow the original application procedure for reapplication.

Protecting Laterite Stone Walls with Clear Acrylic Chemistry

Clear Acrylic system is a clear acrylic-based coating that forms a thin, wet, transparent film on the surface of the laterite stone. This film acts as a barrier, preventing water ingress and protecting the stone from staining and weathering. It can also enhance the natural colour and provide a slight or semi gloss -sheen, depending on the specific product.

Surface Preparation for Clear Acrylic system Coating

Similar to Organo Silane, proper surface preparation is similar for the adhesion and performance of Clear Acrylic coating.(refer to the surface preparation mentioned above)

Application Procedure for Clear Acrylic Coating

Applying Clear Acrylic coating requires careful attention to ensure a uniform and durable finish.

Dilution (if applicable): Some Clear Acrylic coating may require dilution with a specific thinner as recommended by the manufacturer.

Ratio: Always refer to the product manufacturers information for specific dilution instructions. Improper dilution can affect the film formation and performance.

Application Method: Clear Acrylic coating can be applied using:

Spraying: An airless sprayer provides the most even and efficient application for larger areas. Apply in thin, overlapping coats to avoid runs or drips.
Brushing: Use a good quality brush suitable for acrylic coatings. Apply in smooth, even strokes, working in one direction to avoid brush marks.
Rolling: A short-nap roller can be used for larger, smoother surfaces. Ensure even pressure and overlap each pass slightly.

Number of Coats: Typically, two thin coats are recommended for optimal protection and a uniform finish. Allow each coat to dry completely before applying the next.

Drying Time: Drying times will vary depending on the specific Clear Acrylic coating product, ambient temperature, and humidity.

Between Coats: Allow the first coat to become tack-free and dry to the touch before applying the subsequent coat (typically 2-4 hours).
Full Cure: Allow the final coat to cure fully before exposing the wall to rain or heavy moisture (typically 24-72 hours). Refer to the manufacturer’s instructions for specific drying and curing times.

Safety Precautions:

Wear appropriate PPE, including gloves, eye protection, and a respirator, especially when spraying.
Ensure good ventilation during application and drying.
Keep the product away from open flames and sources of ignition (if the thinner is flammable).
Refer to the MSDS for detailed safety information.

Maintenance Tips for Clear Acrylic coating – Coated Walls

Laterite walls coated with Clear Acrylic coating are relatively easy to maintain.

Regular Cleaning: Clean the surface regularly to remove dust, dirt, and mildew.

Method: Use a soft cloth or brush and a mild soap and water solution. Rinse thoroughly with clean water. Avoid using strong solvents or abrasive cleaners that can scratch or damage the acrylic film.

Inspection: Periodically inspect the coating for any signs of scratches, peeling, or damage. Address any issues promptly to prevent water from getting underneath the film.

Reapplication: The lifespan of Clear Acrylic coating depends on the environmental conditions and the quality of the product. Reapplication may be necessary every 3-5 years, or when you notice the coating starting to degrade or lose its protective properties. Before reapplying, ensure the surface is clean and free from any loose or flaking coating. Lightly sanding the existing surface can improve adhesion of the new coat.

Choosing the Right Protection for Your Laterite Walls

Both Organo Silane and Clear Acrylic coating offer effective solutions for protecting laterite stone walls, but they cater to different needs and aesthetic preferences.

Organo Silane Chemistry is the ideal choice for those who want to maintain the completely natural look and breathability of the laterite stone while providing excellent, long-lasting water repellency. It penetrates the stone, offering protection from within without altering its appearance.
Clear Acrylic Chemistry is suitable for those who desire a visible protective layer that can enhance the colour and potentially provide a slight sheen. It also add a wet finish to the walls. It offers good water resistance and protection against staining, and can be easier to clean.

Ultimately, the best system for your laterite walls will depend on your specific requirements, aesthetic preferences, and the level of protection needed based on the local climate and exposure conditions. By following the detailed steps for surface preparation, application, and maintenance outlined in this article, you can ensure the longevity, beauty, and structural integrity of your cherished laterite stone walls for years to come.

Choose wisely and enjoy the enduring charm of your naturally protected laterite structures!

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Disclaimer: Whilst the information contained herein is true, accurate and represents our best knowledge and experience, no warranty is given or implied with any recommendations made by us, our representatives or company, as the conditions of use and the competence of any labour involved in the application are beyond our control. We strongly advise all personnel concerned to conduct their own thorough research and establish a quality control process tailored to their specific needs and requirements. Images shown are for indicative purposes only.

Tag: Laterite brick wall