Tiler came over. We ran shower, stood in there, walked around in there & no leak.... until 15 minutes after he went. He's coming back tomorrow.
Will post outcome for all to read :)
Grey above green baton is end and corner of upstairs showerbase. It is 30mm lower than floorboards that can be seen here. Damage to green timber was always there.
Took some closeup photos. It appears the new joist has dropped leaving fractures in vilaboard and a crack in corner.
Base is 2 layers of vilaboard, tilers mud and 12mm floor tiles.
When water went through there was approx. 150kg (2 adults). Up until then max weight up there was approx...
Hi! We had a level entry shower installed upstairs on the timber floor. Builder checked out the joists & laid cement sheeting, it's all done upstairs but now 2 months later we have a leak in the corner of the shower (coming through downstairs) and an issue at the other end but I'll tackle that...