The following information is an updated application procedure for owners and contractors using the Silox Adobe and Rammed Earth Water Repellent in their protective treatment of asphalt and cement stabilized mud adobe, natural sun-dried mud adobe with straw added, and rammed earth, asphalt, cement, and natural, sun-dried mud adobe homes and structures.

For nearly four decades, I’ve dedicated myself to researching and developing the Silox Adobe and Rammed Earth specialty water repellents. These products have been meticulously crafted to shield earthen materials from the elements. Through our proprietary blend of resins and silicones in the Silox formulas, we’ve successfully protected hundreds of homes throughout both in Tucson and the Southwest.

Ongoing research on the Silox products is a regular occurrence. In fact, as of April 27, 2024, our flagship product, the Silox Original, has recently undergone another improvement, enhancing its water repellency properties.

Adobes come in various types, each with its own characteristics. Cement stabilized, asphalt stabilized, burnt adobe, and sun-dried natural adobe are among the options. Burnt adobe stands out due to its kiln-firing process, which makes it harder and more resistant to water penetration compared to unfired adobes. This type is prevalent in Tucson, AZ, where I reside and operate, and it’s the adobe which the Silox was initially designed to safeguard.

Over the decades, customers have shared valuable feedback about their experiences using the Silox on their homes, whether constructed from adobe or rammed earth. While I’ve long been aware of the varying square foot application requirements based on the type of adobe or rammed earth, I now recognize the necessity of updating my information on these application procedures and sharing my findings accordingly.

This update primarily focuses on sun-dried mud adobes, including those that are “natural” without additives (such as asphalt or cement), asphalt and cement stabilized mud adobes, and rammed earth. It does not address or apply to burnt adobe, an important distinction to note.

Given that sun-dried adobes and rammed earth are typically more porous than burnt adobe, they often require a greater amount of the Silox per square foot for adequate protection. Therefore, the following updated information is provided, incorporating decades of feedback from customers and real-time experimentation and observation in field tests regarding these best practices:

Here’s a revised version for clarity:

It is now recommend applying two flood coats of the Silox using a ‘wet on damp’ method for maximum protection of sun-dried mud adobe and rammed earth. After spraying the initial flood coat, as demonstrated in several of my videos, the second flood coat should be applied before the first coat has a chance to dry. Avoid applying the second flood coat over a completely dried first coat, as the silicones in the Silox will begin to dry and cure, leading to repelling of the second flood coat. This may prevent the second flood coat from penetrating and breaking through the silicone barrier.

In hot, dry weather conditions (for instance, temperatures 90°F or above and humidity below 15%), particularly if you’re spraying walls in direct sunlight (a practice I never recommend in such temperatures), it’s advisable to follow the shade of the house for application. The rule of thumb in these hot and dry conditions is to apply the Silox only on walls shaded from the sun, not in direct sunlight.

In these circumstances, the second flood coat should be applied within 45-90 seconds of the first coat due to the rapid drying of the initial application on the adobe or rammed earth walls.

In hot, low-humidity conditions, you’ll apply the Silox within seconds after the first flood coat. If temperatures are lower and humidity is higher, this rapid reapplication of the second flood coat can be extended to perhaps three to four minutes.