On 16/08/2020 21:23, Vir Campestris wrote:
On 15/08/2020 17:45, Kellerman wrote:
You need professional advice from a Building Surveyor.
Contact your Buildings Insurance Company.

+1

(I wouldn't normally add +1, but this is exactly the right thing to do
in a situation where doing the wrong thing could be _very_ expensive)

Andy

More than that if it has just recently appeared then any delay could
allow it to become considerably worse and even dangerous.

Where I used to live entire semis and the odd detached house or parked
car would occasionally disappear into the ground due to mining
subsidence or sink holes. Old buildings were built on timber frames and
more modern build on concrete rafts so that they might tilt a bit under
provocation from mining subsidence but the walls didn't usually crack.

--
Regards,
Martin Brown