The main function of a masonry paint system is to protect the substrate against atmospheric conditions and to maintain the initial aesthetic characteristics. As an independent coatings test laboratory, we are very regularly called to assist in the investigation of the failure of paints on a myriad of surfaces from wood to metal to cementitious surfaces.
In this case, our specialists were asked to investigate the failure of a EIFS (Exterior Insulation and Finish Systems) which consisted of polystyrene sheets onto which was glued a fibreglass mesh, followed by the application of a base coat and finally the decorative render.
Our laboratory was contacted by a well known fast food restaurant who informed us that the render on the side of the building was failing with pieces of render falling off the building and large holes appearing. A technical inspection was requested and the following week, we had a forensic engineer on site with magnifying glass in hand.
During two hours on site, we felt that the cause of the issue was pretty straight forward. Examining the surface of the EIFS showed that the decorative topcoat was in places delaminating from the base coat, with the formation of cracks in the film, which allowed for the ingress of water which continued to undermine the system.
