I've just finished painting the pebbledash rendering of my house with Dulux Weathershield. The instructions recommend 2 coats, which is what I have given it, but the first coat was thinned by about 20% as the original surface was very porous. Can I include this as one of the coats or does it require a third coat. It looks fine and I don't really want to do it again if I don't need to as it takes two days and costs about £100 in paint. On the other hand I want to be sure it has been done correctly.