Dear neil, sorry to hear about your roof. These climbers can slowly
destroy a building. My experience is similar to yours, except the
building didn't belong to me. It was a russian vine, its job was to
screen a wood shed from the house. It did that all right, but with out
maintenannce this thing had smothered the shed and had started the shed
to lean.
The plant is so quick to get going.
is your Ivy root still left in? My I suggest that if it is to try and
dig it out carefully and treat it with a branded weed killer in a
concentrate form. Hope that helps.