Earlier this year, we thought we were dealing with subsidence. I called the insurer, but it took them two months to send a surveyor.
There are no external cracks, only hairline fissures around the windows receiving direct sunlight. Being half a mile from the river, our soil is a mix of clay and pebbles. The surveyor’s initial verdict was simply "seasonal weather-related movement," which he is confirming in writing.
Even so, I remain cautious. While the cracks are hairline, the windows on the party-wall side have dropped by about 5 mm (though they have been completely stable for the past three months).
We are planning a rear extension on this 1959 end-of-terrace home, which involves taking down the entire rear ground-floor wall and installing a 22 ft RSJ. Will the new footings and steel support effectively mitigate any future subsidence risk?
