The bedroom is 4m long in the length the joists run — the joists are 2 x 8, they are about 4 and a half floorboards away from the wall (around 25 - 30 inches) and they are about 20 inches between each joist. I’m not in the house so these are best guesses at the moment.
Plumber has notched across all the joists far beyond the 35mm allowable by building regs.
As a fix — after raising concerns — the contractors are offering to brace/bridge the joists.
My concern is that will do little to address the problem as it’s adding strength in the wrong direction and it...