External wall insulation application should start with the preparation and verification of the substrate to which we attach EPS or wool. Regardless of whether we are dealing with the substrate in a new building or a already existing building (sometimes with the original layer of insulation, which is to be modernised), we need to ensure that the surface is stable, dry, even and clean. A properly prepared substrate should have sufficient strength, enabling the mounting of insulation.
Furthermore, it must be free of impurities of release agent, dust, grease and comply with the requirements in terms of flatness and surface roughness. Attaching insulation to the untreated substrate or loosening surface (the old plaster, facade paint), may result in a lack of traction between wall and insulation, and lead to serious consequences. During the implementation phase, you can always check whether the surface is well-prepared. Simply rip off fastened board from the wall and assess if either the break occurred in the structure of EPS or, which is unfortunate, it has detached from the facade structure.