I own the ground floor flat of a period conversion that sits on a sloping ground. This means the house flank wall is partially under the ground level (how much under the ground depends on the room. I would say between 30cm and 70cm).
A worker drilled two progressively longer holes on the flank wall with the intention of fitting a broadband Internet cable, only to later realize that the height of the holes was too low, and he was drilling under the ground level (alas..).
As a result, I now have two 100cm (!!) long holes of about 50mm diameter that pierce past the flank wall and get into the ground. My rough estimation is that the holes are about 20cm below the ground level and that the flank wall has a width of about 35cm.
I am trying to understand what would be the most appropriate way to fix these two holes. I am particularly concerned about having weaken any existing damp-proofing, or having increased the chances of water / humidity / damp penetration on the wall from the underground soil.
To make things more complicated, the part of the flank wall the holes go through:
(1) is very close (possibly within) the area were the chimney breast (removed / covered by the previous owner(s)) used to be, so I am not sure they went through the chamber/flue/external side of the chimney breast
(2) may have some layer of thermal / damp insulation material (not sure what it is..) fitted at around 2cm of depth within the wall (see picture)
Thanks in advance