2 storey extension with rendered wall completed in Autumn 2010

Hi, I would say absolutely it is fair to ask. I doubt very much he said that once it was done that it will probably only last 5/6 years? We have experienced some quite varying severe weather over the last 5 years, from extreme cold to very heavy rain, all of which can have a detrimental effect on finishes such as render. That said, if the wall being rendered was bonded properly, and applied in correct strengths for each layer, and a waterproofing additive added, you should still have a good finish. The problem you get sometimes, is that if the render doesnt bond to the wall properly, you can get hollows behind the render, if then this cracks and water enters and then it freezes and expands it will start to blow it off. Hope this helps explain it a little better. Also for future reference, render should always be layered in weaker layers. the base coat being the strongest and then subsequent layers having a weaker render mix. This means that if the there is movement from the base ie the wall it will help minimise cracking. if they aren't layered like that it will crack. Imagine a jelly that has a layer of melted chocolate poured over it, once that hardens if the jelly were to move, it would crack. Its the same principle, albeit a very unusual way to describe it?!?