External thermal insulation composite systems are mostly made of insulation materials and related adhesives and plasters, which are rejected in building biology, for example, due to nonpermeable materials, toxic ingredients, problematic fire performance, contaminated soil and groundwater as a result of leaching algicides and fungicides, as well as other problems during the life cycle of the various components from manufacture through disposal.
It is only natural then that we intended to choose an external thermal insulation composite system (Doser) for the IBN flagship project that would not have any of those problems. On a substructure (vertically mounted “ladders” made of roof lathing and spacers, Picture 1), horizontal mounting strips 25 x 75 mm (1 x 3 in) made of coniferous timber were screwed with an on-center spacing of 62.5 cm (24.6 in) and then the assembly was covered with 50 mm (2 in) thick water-repellent soft fiberboards (wet-processed) as a plaster base (Picture 2).
The resulting cavities (diameter = 21 cm / 8.3 in) were filled with Steicozell blown-in wood chip insulation (Picture 3). As a next layer, a permeable mineral plaster base coat and plaster top coat were applied and, after the plaster coats were dry, another two finishing coats of one-component silicate dispersion paint (Keim-Granital) were applied.
This exterior wall assembly achieves a U-value of ca. 0.10 W/m2K.