Heidi

We had a solid wall insulation system applied to the side of our house 6 years ago. It was rendered with a coloured silicone-based render. This winter regular, rectangular staining has appeared on the surface. Would this be a cosmetic problem only - or the sign of something more fundamentally wrong with the insulation system and dampness trapped beneath? The system is supposed to have a 25 year guarantee. Grateful for any thoughts.