Growing interest insulation very often results in choosing companies with low price for materials and installation, without considering whether technological standards are observed. The analysis of defects occurring in contact insulation systems should warn investors on how to proceed when choosing a supplier, so as to avoid claims for the resulting defects, or in a extreme case, so the insulation will not have to be replaced. It also wants to draw the attention of suppliers and designers towards those major faults when installing the contact insulation, and bring awareness to the general public about deficiencies that could arise, in particular with the implementation of contracts with no technical supervision.

Different prediction methods for the Sound Reduction Index of single building structures in laboratory conditions and for the Apparent Sound Reduction Index in buildings are presented in following paper. A short discussion of methods is done regarding to input data, assumptions of calculations etc. The main part of this paper is focused on a comparison between predicted and measured results, which leads to evaluation of methods´ accuracy. This paper is based on author´s PhD thesis.