The striking layered look is created by the construction process itself: Rammed earth is placed in approximately 12-14cm high layers in a formwork and compacted. As soon as one layer is finished, the next follows – layer by layer, until the desired wall height is reached. This technique not only makes the construction visible, but also gives each component its own distinctive aesthetic.

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Clay earth is a very durable building material when planned and executed professionally. The decisive factor is constructive protection against the effects of the weather – for example through overhanging roof edges, well thought-out details in the plinth area and/or erosion brakes in the form of trass lime or brick strips. Rammed earth in particular is characterized by high durability: Many historic earth buildings have been standing for centuries and provide impressive proof of the durability of this material.

The raw material clay is generally inexpensive and often available regionally. However, the construction itself requires a high proportion of manual labor, which increases the price in countries such as Austria, Germany or Switzerland due to comparatively high labor costs. At Lehm Ton Erde, we have developed technical innovations to reduce the amount of work involved and make the process more efficient. Nevertheless, rammed earth remains an artisanal process whose further development depends heavily on ongoing construction projects.

Rammed earth is locally available, reusable and does not require energy-intensive processing. The clay remains in the material cycle: at the end of its life cycle, it can simply be reused or returned to the earth.

The dimensioning of a rammed earth element depends on the respective application and the requirements for transportation and logistics. With a bulk density of around 2.3 t/m³, the weight limits are a key factor for planning. Elements with a height of approx. 120 cm, a maximum length of 300 cm and a weight of approx. 4 tons are ideal. The wall thickness varies flexibly between 7 and 85 cm – tailored to static and design requirements.

No, rammed earth walls generally manage without any internal reinforcement. Steel reinforcement would hinder the drying process, create stresses and encourage cracking. It would also make it considerably more difficult to compact the material during tamping. The load-bearing capacity is created solely by the solid construction and the specific composition of the material.

Rammed earth elements are produced in a damp state, then cut to size and carefully stored. The drying time is approx. 4-6 weeks, depending on the thickness of the element, the climatic conditions and the air circulation. Only after complete drying do the elements reach their full strength and can be safely moved and loaded.

Rammed earth is a solid material with a bulk density of around 2.3 t/m³ – comparable to concrete. This brings weight with it: one element can weigh several tons. It is therefore important to determine the dimensions in the planning phase so that transportation and installation are possible without any problems. With Lehm Ton Erde, we make sure that the components are compatible with standard lifting and transportation equipment – to ensure a smooth process on the construction site.

Yes – similar to bricks, prefabricated rammed earth elements are laid piece by piece. In order to achieve a closed, homogeneous surface, the joints are then filled with the same base material and retouched. As our material is processed in a moist state and is not stabilized with cement, it can be shaped permanently: retouching work is possible not only immediately after installation, but also years later.

Rammed earth can not only store heat, but also moisture. The top layer of clay acts like a natural sponge: when the humidity in the room is high, the wall absorbs excess moisture – up to around 55 % relative humidity. If the humidity drops, the rammed earth releases the stored moisture again. This passive moisture balance ensures a healthy indoor climate, increases thermal comfort and supports respiratory health.

When insulating rammed earth walls, it is important to choose a diffusion-open insulation material that allows moisture to pass through and thus preserves the natural moisture-regulating properties of the clay. In addition, the insulation must be connected to the rammed earth wall without gaps and airtight in order to avoid air gaps that can lead to heat loss or moisture problems.

The heat transfer coefficient (λ value) of rammed earth is around 1 W/mK and is therefore comparable to concrete. Due to this relatively high thermal conductivity, rammed earth walls must be additionally insulated if they are used as external walls in order to meet current energy requirements and building regulations.

We generally source raw materials from earthworks and excavation projects in the region, with transportation distances of between 15 and 40 km. In most cases, one source is sufficient to realize several projects. Before the material is processed in our production hall in Schlins, it is prepared: screened, crushed and mixed.

Rammed earth walls absorb high compressive forces and behave statically similar to unreinforced masonry. Loads should be transferred at right angles to the horizontal tamped layers wherever possible. The tensile strength is low and can be statically neglected.

Rammed earth and other building materials – such as wood – deform differently under load and over time. While wood reacts strongly to changes in moisture and temperature, rammed earth exhibits what is known as “settlement behavior” (creep). In order to prevent damage, such movements must be absorbed by the structure – for example by means of sliding bearings or special connection details such as slip connections. Such solutions have long been established in the construction industry and can also be used reliably in rammed earth construction.

Similar to brick masonry, rammed earth elements are laid in a bond to ensure even load distribution. In order to safely transfer point loads, the individual elements should be connected and stabilized using a ring anchor or similar details. This creates a coherent, load-bearing wall structure.

As rammed earth only has a low tensile strength, openings such as windows or doors must be structurally secured – usually using separate lintel elements. These can be made of wood, steel or concrete, or can be integrated into a closing rim that reliably transfers the load across the opening. The planning and construction costs increase, especially for larger openings. Early coordination between architecture, statics and construction is therefore crucial.