Are Pirrouet® bricks fully coloured?

Yes. We apply a water-resistant, scratch-resistant coating to the visible faces of Pirrouet® bricks. This transparent acrylic coating is primarily to protect against weathering, so gypsum efflorescence cannot occur with Pirrouet®. Because the coating is only applied to the exposed surfaces, the amount used is minimal, and so is its environmental impact. The coating does not reduce the durability of Pirrouet® bricks.

Pirrouet® bricks are produced using residual materials from the steel industry, specifically steel slag, a mineral-rich byproduct containing compounds like calcium and magnesium oxide. These minerals are added to liquid steel to remove contaminants and purify the metal.

Once the purification process is complete, the metallic fraction is separated and reused in steel production, while the mineral fraction, which is clean and non-toxic, is repurposed to create our carbon-negative Pirrouet® bricks.

This innovative reuse of industrial byproducts not only ensures material purity and safety, but also contributes to a more sustainable construction industry.

The CO₂ storage in Pirrouet® bricks is permanent and chemically bound. During production, carbon dioxide reacts with calcium hydroxide present in the raw materials, forming calcium carbonate, a process known as carbonation.

This reaction creates a limestone-like structure, locking the CO₂ into the brick's mineral matrix. Unlike temporary storage methods, this chemical bond ensures that the captured CO₂ cannot be released back into the atmosphere, making Pirrouet® bricks a durable and carbon-negative building solution.

Pirrouet® uses only inorganic pigments based on iron oxides, known for their excellent UV resistance. Both internal and external QUV ageing tests show that the colour change (Delta E) remains well below generally accepted thresholds – even under extreme conditions with increased UV exposure. In addition, the bricks are finished with a protective coating that provides extra resistance to UV radiation, moisture and pollution. Any colour fading is minimal and not visible to the naked eye.

Our Pirrouet® bricks come with a 10-year warranty.

Depending on the size you choose, you will need the following quantities per m2:

WF (210x100x50): 72/m²
LF50-S (240x72x50):  64 /m2
DF (215x100x65): 58/m2
XXL44-S (440x72x44): 42/m2

The above quantities are guideline values and assume the bricks are laid with a joint of 12 mm. If the bricks are glued, you will usually need more bricks per m2.

Pirrouet® bricks are class IW3, meaning they have the same low water absorption as ceramic handmade bricks. They can therefore be laid using standard mortars and systems (standard joints, thin-bed mortar, glue, lime mortars, etc.). 

Download the processing instructions

Pirrouet® bricks have been tested in accordance with the strict European standards for ceramic bricks. We currently have an Environmental Profile (EP) for Pirrouet®, based on estimates and calculations. This will be validated against real-world production data after one full year of manufacture. That verification process is underway, and we expect the Environmental Product Declaration (EPD) to be available in spring 2026. Once published, the EPD can be used for official environmental calculations. 

If you have any questions, please don’t hesitate to contact us.

Pirrouet® bricks have a very high dimensional stability and are therefore perfect for circular processing. A dry stacking system is currently under development. The mortar industry is also working on a special lime mortar, which will make it possible to recover the Pirrouet® bricks. Please contact us for more information.

As this is a completely new product and technology, we are currently working on achieving the KIWA innovation certificate. This certificate will also serve as the basis for an EPD certificate proving sustainability in figures.

At first glance, the CO₂ uptake of 60 kg per tonne may seem modest, especially when compared to materials like spruce wood, which stores around 623 kg of CO₂ per cubic metre. However, the true impact of Pirrouet® lies in its entire production process. Unlike traditional bricks, Pirrouet® bricks are dried rather than fired, which drastically reduces energy consumption and emissions. This allows us to create a genuinely CO₂-negative product. 

With an annual output of 20 million bricks, we capture and permanently store approximately 2,500 tonnes of CO₂ each year—a significant and lasting contribution to reducing atmospheric carbon. 

Furthermore, unlike wooden façade materials that eventually release their stored CO₂ at the end of their lifecycle, Pirrouet® bricks lock in CO₂ permanently through carbonation, a chemical process that forms stable, limestone-like compounds.

We are currently investigating whether CO2-negative bricks can also be produced as pavers. These require different properties from facing bricks in terms of breaking load, frost/thaw resistance, salt resistance and trip/slip resistance. In addition to developing potentially new, innovative pavers such as CO2-negative paving stones, we are fully committed to producing more sustainable pavers, through dematerialisation and the future use of green hydrogen gas. Clay paving is made from local river clay, a renewable resource which increases natural biodiversity and flood safety when extracted. The lifetime of clay pavers is on average 135 years and the reuse rate is almost 90%(!). Because of all this, our pavers fit perfectly within the circular economy. Clay pavers also have a unique aesthetic; they are colourfast and create an unbeatable atmosphere in outdoor spaces. Clay pavers have been the most circular product for public paving for centuries!

Pirrouet® CO₂-negative bricks store more CO₂ than is emitted during their production. They are made using residual materials from the steel industry, which undergo a carbonation process that permanently binds CO₂. This process continues for some time after production. The net CO₂ storage of these bricks is higher than their overall emissions.

Pirrouet® bricks are, on average, around 30% heavier than traditional ceramic bricks. However, the narrowest Pirrouet® size (72 mm) has the same weight per square metre as standard bricks with a 100 mm laying surface. This narrow format is therefore a sustainable option that typically requires no foundation adjustments.