I have recently been asked to do a rendering job for somebody. They are telling me that it can be done with just one coat. I'm only just starting out as a plasterer after college. I have done a few small rendering jobs but always with two coats, a scratch coat then the final coat. I haven't seen the job yet, so I don't know what the background is likebut I assume it is brickwork. If it is put on using just one coat, what problems are likely to happen? if any.