In article ,
John Rouse wrote:

Houses built before the war are likely to be lime mortar, as cement was
too expensive for normal use, and ivy will penetrate the mortar and
loosen the bricks. I nearly got killed pulling ivy off our garden wall,
about thirty linear feet of wall collapsed when I pulled a strand off
one end and, had I not been nimble on my feet, would have been all over
me.

Don't you mean the Great War? Cement mortar was widespread by 1920,
though it was typically a lot weaker than modern hard mortar.

In any case, ivy will only SOMETIMES damage mortar - in other cases,
it may protect it.


Regards,
Nick Maclaren.