pisä

Pisé is a traditional earth-building technique in which walls are formed by compacting damp subsoil into wooden forms and then removing the forms after each layer has been densely tamped. The method creates solid, load-bearing walls made from earth, typically built up in horizontal lifts until the wall reaches its final thickness.

The material composition of pisé is generally a natural soil mix consisting of clay, silt, sand, and gravel in varying proportions. In some cases stabilizers such as lime or cement are added to improve strength and moisture resistance, and fibers like straw may be included for reinforcement. After shaping, the exterior and interior faces are commonly finished with lime or cement-based plaster to protect the wall from moisture and weather. Walls are usually relatively thick to provide adequate thermal mass and stability, though thickness varies with climate and structural requirements.

Performance and design considerations play a central role in pisé construction. The walls offer high thermal mass, helping to moderate indoor temperatures, and they have good fire resistance. However, they are sensitive to moisture and improper drainage, so proper foundations, waterproofing, and surface protection are essential. In freeze-thaw climates, thicker walls or additional insulation may be required. Construction requires skilled labor to achieve uniform compaction and avoid cracking, and the technique often relies on traditional craftsmanship or stabilized variants in modern practice.

History and use: pisé has deep historical roots in various regions, particularly in continental Europe, and has experienced a revival in contemporary sustainable architecture. Modern rammed-earth buildings frequently emphasize local materials, energy efficiency, and durable finishes, combining traditional methods with modern stabilization and protective plasters.