Folks, i am a DIY plasterer (get that out the road first) can manage skimming but recently my mate asked me to render his house wall just above kitchen window where it is leaking ( a no cost job). You can actually see the cracks. My question is this. I have done a K rend job on my mothers garage and it looks great. I would like to use a ready mix mortar bag to do this then add the peas to match his existing. Can i use ready mix mortar instead of 4 and 1 sand cement mix? I just find it easier having used it to lay slabs last year saves the dry mixing?