Installation of very light thermal insulation with a rendering on a new facade can in principle be done with an adhesive. However, most people don’t trust this because it depends on the state of the facade (wet by rain, contamination due to traffic, etc.). At that moment, they want mechanical fixings, which are anchored in the facade.
In case of a ventilated surface with more heavy thermal insualtion like cellular glass and with a heavy cladding, an improved mechanical fixing is needed.The patent of Willy Trittenbach, once a collegue is a nice example of such a very stable fixings. But stainless steel has thermal conductivity of 15 W/mK and GLAPOR cellular glass about 0.05 W/mK or a factor 300. This means that a 6mm screw cinducts the same amount of heat as a cylinder GLAPOR cellular glass with a diameter of 100 mm, which is a huge cold bridge. Besides the screw, also the legs are passing the cellular glass. The patents mention at least one fixing in every boards 450 x 600 or a cold bridge of about 10% of the thermal insulation. To remove this cold bridge, a new patent was taken.
This new patent eliminates works with a double layer insulation, separated by a board, which is fixed on the walls. In this case, there is no direct connection by a long screw between the surface of the thermal insulation and the wall.
However, in Germany ventilated facades have to be insulated with thermal insulation with melting point above 1000°C according to DIN 4102-17. Check the German product datasheet before ordering the thermal insulation in case of Germany.