Raw material circle instead one-way utilization - Sustainable insulation of facades

The basic idea of the raw material cycle is the dismantling of building materials after the end of use and re-use. In this way, buildings become the raw material storehouse of the future. This is also called circular construction or "cradle to cradle".

Here for example - facade insulation:

Since 2019 there is the first zero waste external thermal insulation composite system (ETICS) that can be dismantled after its service life; each type of component can be separately recycled. Here you can find out how the recyclable ETICS works.

Chapter overview:

1. Why are facades insulated?

2. What is the system build-up of an ETICS?

3. How does the dismantling of weber.therm circle work?

4. Conclusion

Why are facades insulated?

Today facades are insulated in new buildings and renovation projects to save energy costs in the long term. Various methods can be used for this purpose, which differ in terms of materials and environmental compatibility. In addition to synthetic insulation materials, such as expanded polystyrene (EPS) or phenolic rigid foam (Resol), there are mineral materials made of stone and glass wool or renewable variants made of wood fibers or hemp, for example.

Anyone who decides to insulate with a mineral ETICS can also reduce the burden on the environment and choose a sustainable, recyclable system - weber.therm circle.

Mineral or full mineral ETICS – what is the difference?

One speaks of a mineral ETICS if the insulation boards are made of mineral wool. Mineral wool is a generic term for glass wool or stone wool. In the case of a fully mineral system, all components from the insulation to the bonding/reinforcing mortar and overlay render are mineral.

Good to know: mineral insulation provides high fire protection, as stone and glass wool are not combustible. Fully mineral systems therefore offer the highest fire protection.

What is the build up of an ETICS?

First, as a rule, ETICS should always be installed by skilled tradesmen. They consist of three layers that are matched to each other: insulation boards, reinforcement layer and external coating of render, clinker, glass or ceramic. Rendered facades can be additionally painted, but this is not always necessary, as mineral overlay renders (top coats) and ready-to-use ones in pasty (wet) form are generally through-coloured.

Layer by layer

First, large-format insulation boards are glued to the masonry or, in existing buildings, to the old facade. Depending on the substrate, the insulation material, the building height and location, the boards are additionally doweled. A special reinforcement layer is then applied onto the insulation material to strengthen the construction. It consists of a reinforcing mortar into which a reinforcing fabric (woven mesh) is embedded. This layer absorbs stresses within the facade and prevents cracks in the base coat render. In most cases, a layer of render (overlay render as top coat) is then applied. Biocide-free mineral top coat renders are particularly durable and eco-friendly. Ready-mixed top coat renders in pasty (wet) form can now also be produced without environmentally harmful biocides. Optionally, a weather-resistant facade paint can be used.

In this classic structure of ETIC systems, the individual components are glued and thus permanently connected to each other. This makes recycling difficult. When the building is demolished, these materials are therefore usually disposed of mixed together instead of being used a second time. Since 2019 the first recyclable ETICS weber.therm circle has been available, which does not require a bonding mortar at all. Each layer's materials can thus be returned to the raw material cycle.

How does the dismantling of weber.therm circle work?

Materials can only be re-used if they can be separated by type. This is possible with the first recyclable and so far sole approved ETICS weber.therm circle that can be degraded according to a type of component. In this system, the mineral wool insulation boards are not glued with a bonding mortar but mechanically fastened.

Dowelling instead bonding

The specialist tradesman fastens the insulation boards, specially designed for this system, to the masonry with screw dowels. This is followed by a separation layer consisting of a base coat of mortar and a special fabric (woven mesh). This so-called separation mesh facilitates the removal of the exterior shell from the insulation board during demolition. As with conventional mineral systems, this is followed by a reinforcement layer and an exterior coating.

Dismantling: separate layers from each other

During dismantling, the render layer is first cut open. The render and the fabric are gripped with an excavator shovel and pulled off. The separation fabric ensures that the insulation material is detached from the render. Then the steel screws and dowel heads are removed from the insulation boards. Finally, the mineral wool boards can be easily removed from the wall.

Benefits of a recyclable ETICS

• The masonry remains almost in its original condition when weber.therm circle is removed. This is particularly important if a conversion or extension is planned.
• All dismantled building materials - mineral wool, dowels, screws, reinforcing mortar, overlay render and woven mesh, can subsequently be collected and recycled as raw materials.

Conclusion

A facade insulated with ETICS lowers heating costs and thus helps to reduce CO2 emissions. Furthermore, an insulated building envelope is a prerequisite for a heating system with a low-temperature flow. So anyone thinking about buying a heat pump should have the facade insulated beforehand. Building owners can also contribute more to the sustainable building by choosing a thermal insulation composite system. By choosing the insulation material and its re-usability, they decide whether to conserve precious resources and reduce their own ecological footprint. For building owners, the demolition or conversion of their house may be a distant prospect. In view of ever scarcer resources, however, there is a growing awareness of the need for buildings that are built in a recyclable manner. Thanks to the weber.therm circle insulation system, which can be recycled by type, today's building materials are tomorrow's raw materials.

Professional tip

On top, the craftsmen are certified by the system manufacturer for the application of weber.therm circle (with general approval). Since it offers high fire protection (class of reaction to fire A 1), like all all-mineral systems, additional fire protection measures, such as fire bars, which must be used with EPS systems, are not required.