Any advice on using this product for finish coat on XPS insulation which has been fiberglassed meshed and rendered. Best mix sloppy or thick and how long to leave before sponge floating, finish effects etc. I'm in Bulgaria renovating my future retirement cottage and am told it's one of the best products to use for the climate. I'm not a renderer but can do a decent enough job , it's product knowledge I don't have and pretty much can't find in-depth instructions for correct use of this product. Any tips or advice ?