This way will be fine after looking at the video.
well after digging more rubble out i have found another RSJ (girder) 750 mm from one at wall.
i think i just need to slide in new 5x2 into the two girders with the 4x2 on top .
I feel much happier knowing there must be beams running right across the bathroom section so no shower in the underpass.
THANKS AGAIN ALL WHO POSTED I SAVED MY NO CLAIMS :banana::banana: