Hemp lime bricks: Insulates. Regulates. Protects.

The Versatile Properties of the Schönthaler Hemp Bricks

Imagine a building material that makes construction possible without additional insulation.

It is lighter, harder, more durable, and more resistant to environmental influences and fire hazards than comparable common alternatives. It keeps indoor air healthy and low in odor, regulates humidity, and allows visually appealing design.

In addition, it is sustainable in production, use, and recycling, and made from a renewable raw material that can produce enough material for a single-family home on one hectare of land in just half a year.

Sections from cutting or milling and retired samples can simply be shredded and mixed into the production of new material without noticeably affecting the properties.
For anyone hearing or reading about the many positive properties of hemp bricks for the first time, it’s hard to believe. But this building material of the future already exists, and it can be used in your next project affordably and with little effort!

We are happy to inform you in a personal consultation about the advantages of hemp bricks for your individual application. The most important properties at a glance:

Hemp bricks are…

…temperature-regulating: Hemp bricks cool in summer and warm in winter (10+ hour phase shift). An ENEA study shows indoor summer temperatures in Sicily of about 26°C without air conditioning.

…humidity-regulating: They absorb moisture and slowly release it again. Hemp bricks are breathable and diffusion-open, so no vapor barrier is needed.

…sound-insulating: The rough surface improves room acoustics. Example values: hemp lime stone 38 cm with plaster: -48 dB, 12 cm with plaster: -41 dB. Interior wall systems with -57 dB and -66 dB are also available.

…efficient and economical: Heating and cooling needs are reduced. No cost for additional insulation. Perfect for low-energy and passive houses (e.g., 38 cm wall = Climate House A Nature).

…easy to handle: Very lightweight; can be cut/milled with standard tools and built with lime mortar. Also possible to mix on-site as hemp concrete. Reinforcement mesh is only needed in critical areas.

…an alternative to building with wood: Hemp grows about 50 times faster than comparable amounts of wood. One hectare of industrial hemp produces enough biomass within 5 months for a small single-family house. Hemp bricks combine the advantages of wood and clay.

…healthy: Hemp bricks prevent mold and pests, purify indoor air (thanks to natural lime), raise its pH level, neutralize odors (ionization), and reduce harmful radiation. They are produced without chemical additives.

…100% natural, without compromise: Made from only two natural materials using a cold-air process. CO₂-negative production and fully recyclable — can be reused as a building material even multiple times.

…future-proof and sustainable: A durable material that continues to harden over time and becomes even more resistant. An example of future-proof building, Cradle-to-Cradle design, and a contribution to the circular economy.

Fire Safety

A property of hemp bricks that deserves separate emphasis and illustration is fire safety. Other natural materials often have low or inadequate fire protection, which is a main reason they are not used in certain projects.

The Schönthaler hemp bricks are hardly flammable and do not ignite due to heat or radiant exposure—even over long periods.

In numerical terms, they meet the following standards:

Hemp bricks 12 cm without plaster: EI 45
Hemp bricks 12 cm with plaster: EI 60
Hemp bricks 30 cm with plaster: EI 240
Fire behavior: B, s1, d0

Indoor Climate

Hemp bricks regulate indoor humidity by absorbing moisture from the air and slowly releasing it again. Natural lime disinfects the absorbed air and increases its pH level.

The ideal humidity in living and sleeping spaces has a huge impact on our well-being, and also on energy savings. With the right humidity, people feel comfortably warm even at lower temperatures.

Hanfsteine schaffen ein behagliches Raumklima

ionisation

Hemp bricks are able to break down persistent odor molecules by absorbing and splitting them. This shortens the perception of the smell. Odor molecules that are stored inside the material are released back into the surrounding air only slowly, so they are barely noticeable again.

Condensation energy

When hemp-lime absorbs water vapor from the air, condensation energy is released and warming occurs. When the water is released back into the air, the evaporation energy needed is taken from the water, causing cooling.
With hemp bricks, this leads to natural cooling in summer and warming in winter.