Plascon Quality Woes

I paints my house a few years ago with Wall and All. It’s the most expensive paint in the market. The thing discoloured after about 5 years. Plascon tried everything claiming the runoff from my slate waterproofing caused the damage. They off course could not explain how the boundary walls had the same damage. They did tell me Wall and All was not suitable for a boundary wall ( I still don’t understand the logic).Eventually they offered 4 cans of paint as settlement because the guarantee was for 12 years and I was nearly half way there. I had bought 10 cans originally. We settled on six. Of course no labour compensation (the most expensive part). I painted the house in around September last year with Wall and All again. It is February and the walls are now blistering…looks as though water is getting under the paint…amazingly never happened before in the 14 years that I have owned the place…I wonder what the excuse will be this time…