Clarifying “Pisé” in Morocco: Mud Brick vs. Rammed Earth

“Pisé” is a widely used building material in Morocco, but it can be confusing because the term is used in reference to several different building techniques. Understanding the distinctions between mud brick, traditional rammed earth, and modern rammed earth, as well as the types of plaster used, is important for anyone planning a construction project. Here, we clarify these materials and techniques to help you make informed decisions and communicate effectively with your contractor.

- Mud Brick, or "adobe brick" is a traditional material made by mixing earth with water and straw, then forming it into bricks and letting them dry in the sun. Mud bricks have been used for centuries, providing excellent thermal properties.

- Traditional Rammed Earth: This method involves compacting a mixture of damp earth into a formwork to create solid walls. It’s known for its robustness and aesthetic appeal.

- Modern Rammed Earth: While similar to traditional rammed earth, this modern variant often includes additional materials like cement and steel reinforcing to enhance strength and durability. Despite frequently appearing in internet searches, modern rammed earth is not commonly used in Morocco. It requires structural engineering similar to concrete.

- Traditional Mud Plaster is applied over walls to create a hand-made finish of natural mud. It requires periodic maintenance, especially in regions with high humidity or exposure to the elements.

- Modern Cement Plaster, also called Stucco, provides a more durable and longer-lasting finish compared to mud plaster. It can be designed to mimic the appearance of traditional mud plaster.

1. Thin plaster coating on a modern concrete block wall: This is a widely used modern construction method where a thin layer of plaster is applied to block walls. It can be colored and textured to resemble traditional finishes and even include bits of straw to mimic adobe.

2. Traditional Rammed Earth: As previously mentioned, this involves compacting earth into formwork to create solid, load-bearing walls. It’s admired for its rustic natural beauty and thermal mass. It can be left exposed but is normally covered in some kind of plaster.

3. Traditional Mud Brick: Mud bricks are handmade and dried naturally, then stacked to form walls. They offer good insulation but require regular maintenance. It can be left exposed or covered in plaster.

4. Engineered Rammed Earth: Although not widely available in Morocco, this technique incorporates stabilizers like cement to improve strength and longevity. It is typically left exposed.

It's important to note that traditional mud plaster walls need “refreshing” every few years, depending on the exposure and climate. To reduce maintenance, some opt to use modern plaster, which can last longer and still achieve an adobe-like appearance. For example, "Villa des Oliviers" utilized traditional rammed earth covered with a modern cement plaster layer. The Villa in Marrakech utilized adobe mud bricks covered with cement plaster.

When working with a contractor, ensure they understand the specific type of “Pisé” you want and confirm their ability to execute it properly. Ask to see examples of their past projects. Clear communication and planning are key to achieving the desired outcome for your project.