Experimental programme to assess ETICS cladding durability

The paper reports on the experimental evaluation of the durability of ETICS cladding through accelerated laboratory ageing, which is now being developed by BEST – Polytechnic of Milan. The experimental programme as a whole includes accelerated laboratory ageing, long-term outdoor exposure, comparison and analysis of results. Four types of specimens have been built with masonry wall acting substrate EPS as insulation and polymeric additives incorporated in the base coat mortar. Of the additives included in the mortar, two were prepared with acrylic resin and two with vinyl resin. Additionally, for each type of specimen, one included a typical finishing coat and another one an acrylic painting. For each series of ETICS specimens, a one set will be aged and the other remains as the (cladding system reference set). There are also four pairs of sets of smaller scale samples on which disruptive tests are to be completed. The ageing cycle consists of 125 UV cycles, 125 summer thermal shock cycles and 50 winter thermal shock and freeze-thaw cycles. In order to assess performance decay on the reference specimen and on the aged specimens at the end of their service life, several disruptive tests will be carried out, including: water absorption, water vapour permeability, tensile bond strength of adhesive and of base coat to insulation, render strip tensile tests, and pull off tests. Non-disruptive tests (e.g. record of T [°C], RH [%] and heat flow) are being conducted throughout the ageing process and, at every end of test cycle, characterization tests are carried out to assess changes in thermal conductance, moisture transfer properties, dynamic effects and thermal inertia. Infrared thermography and capillarity tests are also being carried out and photos are taken in order to survey evolution of cladding degradation.