Energetic Renovation. ETICS In Comparison

Some media sharply criticize energetic renovation measures by installing an ETICS. The reports go in various directions

Author: Markus Haberland | Photos: Baumit

There are statements about the fire behavior of thermal insulation composite systems. Information that wall surfaces can no longer “breathe” and there is an accusation that there is a higher risk of mold formation due to the installation of facade insulation.

The commissioning of energy renovations for buildings from the private portfolio is declining. The advice of an ETICS system has become more intensive, there are many, sometimes critical questions: "How long can a thermal insulation composite system last?" Or "How are insulation boards disposed?" The discussion led to the opinion that ETICS systems dismantled after a certain life cycle and cannot be disposed of.

Properties of the ETICS

EPS insulation boards are an economical variant for creating an ETICS system. Long-term experiences with EPS panels are sufficient. In the past, media attention for EPS panels has focused on the fire behavior of the system. Very emotionally formulated articles distorted the view of the property profile of the EPS systems, triggered by fire scenarios that affected the facade surfaces from the outside. From this, the installation of additional fire bolts in the EPS systems was derived in early 2016. The "flame retardant" classification in fire classification is now even more certain. Large-scale fire tests confirm that the additional fire bars that are introduced effectively limit the spread of fire even when the fire load is external.

Resole and rigid polyurethane foam panels have the common property of low thermal conductivity and therefore already have good insulation performance with low insulation thicknesses. In the event of fire exposure, there is no melting process in the insulation material, so that no fire bolts are necessary for these systems to achieve the "flame-retardant" classification.

Systems made of mineral wool insulation boards are largely non-flammable. The classification depends on the cleaning systems used. The diffusion openness to water vapor is comparable to a dormant air layer and is therefore very high.

Wood fiber insulation boards have a lower thermal insulation capacity than other insulation boards. The big difference lies in the production in the wet and dry process. Due to the greater bulk density, there is a higher heat storage behavior, which results in a delayed cooling behavior on the outer surface and thus greater resistance to contamination. Wood fiber insulation boards are also used as a system on solid masonry, so that these boards can also be used to renovate existing buildings.

With a thermal jacket around the building envelope, an even situation is created on the masonry - energetically speaking. Thermally decoupled from the external conditions, the interior surfaces show a uniform and unchanged temperature situation. The thermal bridges have, so to speak, been deprived of the possibility of transport to the heat drain. This greatly reduces the risk of mold growth.

Lifespan of ETICS systems

A study published by the Fraunhofer Institute shows that the ETICS can largely be classified as defect-free and are therefore comparable to facade surfaces without insulation. In addition, an estimated time for the maintenance of the facade surfaces is given with an average of 22 years.

Specialists have the opportunity to offer their customers a maintenance contract for the facade surfaces. The BV-Farbe and BAF have published guidelines for this as the basis for the agreement.

For the Fraunhofer study: www.bit.ly/2GS6PB8