United Kingdom 
We just took up old underlay from our new house , and there are Ivy roots attached to the underside . There is an Ivy growing up the side of the house , on the other side of that floor
16 Aug, 2021
Answers
Are we to assume the Ivy has found a way in from outside?
Welcome to Goy by the way.
17 Aug, 2021
Does the ivy appear to have come through the wall, or is it an old house with a cavity underneath rather than solid foundations? My mother's lovely house was built after WW1 and had large cavities under the floors . Every now and again we'd find a strand of bindweed creeping up the hall wall!
20 Aug, 2021
Sorry I don't understand what you're asking.
17 Aug, 2021