Sustainable insulation with wood fibre

The Ehehalt family from Essen are very environmentally conscious and sustainability plays a major role - even in their home. This is why they opted for wood fibre insulation when renovating their semi-detached house, which is over 100 years old. "We felt that synthetic, oil-based insulation materials simply wouldn't suit such an old house," says Ulrich Ehehalt. Insulation with the new lightweight wood fibre insulation boards is particularly attractive when renovating detached and semi-detached houses in solid construction. Together with the mineral plaster and paint systems from KEIMFARBEN, facades can be insulated in a particularly durable, resistant and sustainable way.

What is probably mankind's oldest building material is becoming the building material of the 21st century. Wood has decisive advantages over all other building materials: it grows back, its use conserves resources and protects the climate. And last but not least, the sustainable material also impresses on a health and emotional level. In our daily dealings with buildings and architecture, wood creates a beneficial connection to nature. One of the many areas of application is wood fibre insulation. Wood fibres have excellent insulating properties and an outstanding ecological balance. They reduce CO2 emissions in two ways. Firstly through the natural CO2 storage effect during growth (photosynthesis) and secondly through the energy savings in the thermal insulation system.

Existing houses are more than just "four walls". They are places with memories, created by generations before us. They need to be valued and preserved. This was also the wish of the Ehehalt family, who bought a semi-detached house in Essen that was over 100 years old 10 years ago. After the purchase, the roof and basement ceiling were insulated and the windows and front door were replaced. Now the facade with an area of approx. 130 m2 was to be renovated. At the same time, a photovoltaic system was installed on the roof. For the insulation, the couple opted for a mineral system from KEIMFARBEN with the insulating material wood fibre.

According to Ulrich Ehehalt, the decisive factor in favour of this insulation material was "first and foremost the fact that it is a renewable raw material that can also be recycled. Good moisture regulation was also important to us." This is one of the most outstanding properties of wood fibres as an insulating material. The material can absorb up to 15 % of its own weight in moisture and also release it again - with undiminished insulation performance. The diffusion-open structure of wood fibre insulation materials supports moisture management, protects against mould growth and makes a significant contribution to a healthy living environment.
The Ehehalt family received in-depth advice from the Rickers painting company. Founded in 1952, the family business is based in Essen and is now run by the third generation of the family, junior manager Jan Rickers and senior manager Ulrich Rickers. Three master craftsmen, a team of 15 skilled workers and a dedicated office administrator form the heart of the company. Ulrich Rickers processed his first thermal insulation system in 1980. Rickers has been using mineral insulation since 1990. Even when using the insulating material EPS, the remaining structure of the ETICS is completely mineral.

Ulrich Rickers attaches great importance to providing his customers with detailed advice. In his experience, this is honoured. "The customer realises whether I'm interested in finding the best solution for them. I don't want to be criticised later as a consultant tradesman: We heard there was another system and you didn't talk about it." Consultancy also includes aspects of ecology and healthy living. Wood fibre insulation, for example, improves sound insulation, which contributes to a better living environment, especially near busy roads.

GUTEX Thermowall-L 160 mm insulation boards were used for the ETICS on the single-family home in Essen. The plinth was insulated with plinth insulation boards 035 140 mm. The facade insulation begins above the water table > 30 cm. At the beginning of the work, the plinth area was protruding; afterwards, the area was to be recessed. Base areas are generally more exposed to moisture or mechanical loads than the facade surface. Therefore, with regard to any repair or maintenance measures that may need to be carried out at a later date, the recessed plinth design is the best technical solution and enables cost-effective refurbishment with little effort. Only the plinth surface is refurbished without having to interfere with the facade surface. In line with the demand for long-lasting, sustainable systems.

Ulrich Rickers confirms that the processing of the wood fibre insulation boards does not differ significantly from insulation with mineral wool or EPS. This assessment is also shared by the site managers responsible for the project, Robert Koch and Martin Schwarz. However, wood fibre insulation boards must be stored in a dry place. If moisture draws over the cut edge, there is a risk that the dimensions of the board will change, which can later lead to damage to the reinforcement and plaster. At the construction site in Essen, the boards were stored by a wholesaler, delivered daily and processed just-in-time.

One challenge for Rickers at the Ehehalt family's construction site was the installation of prefabricated external venetian blind boxes. This is a system solution for installing external venetian blinds in ETICS systems. They are individually configurable, delivered directly to the construction site as prefabricated components by GUTEX and integrated flush with the surface of the insulation layer as part of the façade insulation work. The precision of prefabrication pays off for the craftsman in many ways. Among other things, it speeds up work processes on the construction site and drastically reduces the susceptibility to errors in detailing.

As the new generation of wood fibre insulation boards - marked with an "L" - is light and compact, it can be moved quickly and easily on the construction site. Gluing and dowelling is carried out as usual. Only a standard 8 mm masonry drill bit is required for dowelling. The panels can be easily cut to size using an electric foxtail. However, Rickers has invested in a Mafell wire saw, which can also be used to precisely cut mineral wool panels. For this purpose, Mafell carried out a familiarisation session at the construction site. Precise cutting is a very important aspect for Ulrich Rickers, particularly in terms of sustainability in the use of materials. The thicker the insulation boards become, the greater the risk that the cut will be crooked and that insulation residues can no longer be processed. Disposing of insulation waste is also a cost factor.

The service life of an insulation system is largely determined by the quality of the surface. It protects the underlying insulation layer against moisture and other environmental influences. For the ETICS in Essen, KEIM Brillantputz was used as the finishing coat in accordance with the approval - a high-quality mineral thin-layer lightweight render based on white lime, white cement and valuable marble aggregates. KEIM Putzgrund was used underneath to give the wall an even texture.

Insulating the façade in harmony with nature is still the right decision for the Ehehalt family "to become a little more sustainable". And in addition to the much more attractive facade, the feel-good effect has also materialised very quickly: "In summer, the house is 1 - 2°C cooler and in winter the rooms don't cool down as quickly. Gas consumption has been reduced from around 15,000 kWh to 8,000 kWh," is the conclusion of the marriage so far.
For Ulrich Rickers and his team, insulating with wood fibre is an opportunity to work in an aesthetically pleasing and responsible manner and to position themselves as pioneers. After all, customers are increasingly looking for craftsmen who think ecologically.