K Rend on a lime mortared house

[Scarophion]

Good evening,

I've recently moved into a Victorian terrace that was covered in cement rendering for the last 30 years. The builder who removed the rendering recommends that I re-render with K Rend (silicone) instead of lime because, he claims, it is breathable. The K Rend website certainly claims that it is.
I am hoping for other opinions. Surely, even if it is breathable, because it is cement it will crack because it is not as flexible as the lime mortared walls?

You may have come across Mr Pete Ward, who is very much against anything other than traditional materials (there are even links to his articles in this forum's wiki!)



But this is just one view and I was wondering what other plasterers think.
I've also read about acrylic rendering, which is supposedly breathable and very flexible. I expect it is quite expensive.

I am interested in any opinions.

Thanks.