Top Argex building blocks are a construction material with a mission:
The continuing energy crisis, heating of the earth, the new EPB-standards and the insulation problems related to them, have been the cause in Europe to thoroughly review the outer walls, roofs and floor structure of buildings. The aim was to reach an optimal combination of price, quality, sustainability and comfort. The result has been an expansion in the range of possibilities to reduce warmth-loss drastically in our buildings.

To achieve perfect living comfort you have to go beyond just limiting warmth loss.

In our northerly areas, where weather conditions can change any minute, limiting warmth loss alone is not enough. We also have to take into account the dynamic character of a wall, in specific heat capacity, thermal inertia, surface temperature and all other elements influencing a wall. It is also important to realize that thermic comfort does not automatically translates into living comfort. Indeed, there are other factors that come into play when determining living comfort. Think about acoustic comfort (how noisy is a wall, can you hear a nasty echo?), fire safety, sustainability and user friendliness (how easy is it to drill, mill or saw it?).

 Developed in the laboratory to create the perfect durable building block

Several European research laboratories and universities have developed the Top Argex Building block, together with a few dozen manufacturers. This building block is designed to meet all these demands: not only does it guarantee a good thermal insulation and curtailment of heat-loss due to the cell-like structure and amount of air between the individual granules, it also has a high sound-absorbing ability making it acoustically ideal. Furthermore it is fireproof, durable, easy to use and surprisingly light!
Topargex® is a quality label and a trademark, to safeguard the quality of this product. To be able to use the label, the manufacturers who are producing the Topargex® building blocks have to comply with strict technical demands. Of course we comply, since we have a 3-generation long tradition of excellent quality, that connects nicely with the high quality standards of the Topargex® building blocks. The Topargex building blocks are easy to recognize by their label “Topargex”, which is printed on the pallets or binding straps, making it visible for everybody.

An ideal building block to construct houses, schools and hospitals

The high demands for a Topargex building block regarding weight, compressive strength, isolation value, composition and drying times, give each of these building elements unique technological features, making them ideal to construct more complex structures like commercial housing, public schools, hospitals, industrial facilities i.e. The ingenious combination of features of these concrete blocks ensures that they are perfectly suited to be used in buildings for people to live in or stay in for a longer amount of time. If you want to build a school or house, it helps a lot that said building is able to retain its warmth and at the same time should be fireproof, has great acoustic abilities and is easy to adjust. All this combined makes Topargex and ideal building material.

Argex: durable and applicable

The “secret sauce” of a Topargex building block consists of Argex, cement and natural aggregates. Especially Argex is an interesting component of this mix, because this is a complete natural product. Argex consists of nothing more of small granules of clay, being mined in the heart of Flanders. After being mined they are being processed to meet the specific construction demands of builders all over Europe. It is a humble product that has a surprisingly versatile scope – for example in thermal floors and acoustic walls as well as in the composition of the super light and non-flammable Argex concrete, which in turn is being used to assemble the Topargex building blocks.

Topargex® is recommended for:

  • Single-family, multi-family and commercial housing
  • Public buildings: schools, hospitals, …
  • Offices and industrial buildings
  • Anywhere where a comfortable living space needs to be created


Topargex® has been developed in cooperation with several European laboratories, universities and leading producers of industrial construction materials. The patented production process of these building elements through high-tech installations guarantees a high stableness, stability and pressure resistance.
Thanks to the intrinsic features of the Argex granules (40% air enclosed in baked and expanded clay) integrated in the concrete skeleton, many experts consider Topargex blocks the ultimate combination of often conflicting features like bearing power, isolation, warmth and acoustic comfort.  The big amount of air is striking for a building element that comes across as heavy but is surprisingly light, a feature not to be underestimated, since lightness gives way for a speedy processing and guarantees cheaper logistical expenses.


  • Thermal insulation
    K value of 0.54 W/m²K with “only” 3 cm of insulation (λ = 0.04) for 14 cm thick Topargex blocks, heat loss through the joints λ = 0.35 W/mK
  • Thermal inertia
    reaction of the wall to temperature fluctuations, “how comfortable the wall feels to touch”; the heat capacity of Topargex blocks is twice that of cellular concrete blocks
  • Noise attenuation
    There is no difference between a concrete wall and a Topargex wall, in spite of the fact that the latter’s density is just half. This is due to the microporous cellular structure of the expanded clay pellets.
    E.g. 14 cm thick block (4/1.2) > 47 dB attenuation
  • Acoustic absorption
    Topargex walls have excellent sound absorption characteristics. NRC value = 0.50 – even with two paint layers.
  • Fire resistance
    Topargex blocks provide excellent results in relation to fire-resistance.
    Some examples: Solid 14 cm Argex blocks: Rf = 3 hours, 19 cm = 6 hours
  • Pressure resistance
    Topargex blocks have enough compression strength to be used for the construction of buildings of up to three stories.
  • Mechanical attachments
    As this is a cement-bonded product, radiators, cabinets etc. can be fixed to the wall without special plugs, and stay there for a lifetime. Other (baked) bricks are performing much worse in this regard.
  • Plastering
    Because of the rough surface, there is no need for any extra binder coating (as there is with bricks/hollow blocks). This reduces the cost of rendering and ensures cleaner/straighter plastering.
  • Processing
    Topargex blocks are easy to handle, bond easily with the mortar and can even be glued in place. Because of their low weight and large size (on average 35% greater surface area than a hollow block) a bricklayer can get much more work done in the same time.