Cutting small rectangle out of K-Rend render

[plastermm]

Dear Forum,

I have a K-rend rendered house front and would like to install a flushed video entryphone next to my door which would require to cut a reactangle out of the render. What would be the best method to avoid cracks or other damages to the render ?

Thank you
Markus

 

[bobski]

Small Angle grinder for most of it.

And a decent blade in a (oscillating) multi tool for the finer bits.

 

[Monkey Boy]

Or big 9” grinder and cut from inside house, that way if your accurate you don’t need the multi tool for the corners

 

[plastermm]

Small Angle grinder for most of it.

And a decent blade in a (oscillating) multi tool for the finer bits.

Thank you. Any experience with a particular brand ?