Hi I wanted to put this in the rendering plastering trades section but couldn't click on that topic title for some reason. Has anyone rendered onto external polystyrene insulation? Its actually the base of my founds an EPS insulated raft. The two products i'm looking at are Aquabase EWI 226 a silicone render system with a fiberglass mesh or a cement slurry aquamat elastic with either 10cm polyestewr fleece or fiberglass mesh   Anyone done this before and g