letter no. 1
My ceiling has a damp patch. Is that my leak or my upstairs neighbour's?
the desk replies — Statistically it is water from above — the flat upstairs or a common riser. Photograph the patch with dates, report it to building management in writing, and do not open your own ceiling before the source is identified. A leak from the neighbour's internal pipework is their liability; one from a shared riser is the building's.