Many thanks for the answer.
I'll try the mixes suggested and see how rogh the surface is.
I guess the hardest thing to do is to get it to match the existing render.
I need to hack off and replace about 1/2 sq metre of blown rendering to the front wall of my house, under a window.
Is there a premixed render generally available or do I need to mix the render? If so, what is the recommended mix and how do I go about getting the same rough texture?
Does anyone have any experience of the Big Bear brand of tools at Screwfix?
They are presently selling a 40cm electric chainsaw for under £70 which is very cheap.
Are these products any good?